I guess that was a 'pun intended'. For one, it needs a runway to take off and two, not many people would be able to afford it along with all the airport rigmarole needed which of course would also require a pilot's licence.
Still, it's interesting seeing the advancement in technology. Each step is a step towards something really worth while.
Engineering and Technology Thread
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Dannie Boy
- Hero
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Re: Engineering and Technology Thread
Takes me back to my youth and watching a cartoon “The Jetsons” - we were all going to be up in the sky!!
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pharvey
- Moderator
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Re: Engineering and Technology Thread
"Hope is a good thing, maybe the best of things" - Yma o Hyd.
Re: Engineering and Technology Thread
Indepth look at standby home generators.
This subject could do with a bit more in depth information for anybody interested.
For those that do not know me I have spent a big part of my working life repairing, operating and maintaining a multitude of different types of generators, along with their engines and distribution systems. Right from a 32 volt DC generator as a 10 year old on the farm that I grew up on, through a 5 year apprenticeship in a rewinding and repair shop, on to serving as both a ships electrician and later the chief engineer on both AC and DC systems up to 6 kV on oil rigs for more years than I want to remember!
(no Sherlock, NOT on the Titanic)
Oh, and along the way I owned and flew helicopters for several years, one of which had a
28 volt combined starter / generator controlled by a carbon pile voltage regulator!
GENERATORS
All generators are not created equal, and in Thailand there seems to be an endless and confusing array of choices. However, as this is about small portable AC generators suitable for use as a backup home supply, I will try and stick with them.
It also refers to 220 volt 50Hz single phase, if you have a 3 phase supply it is still possible but different equipment will be required.
It also assumes that you own the house, as I doubt any rental landlord would allow a permanent installation. If you live in a Condo, you will probably be banned from ANY type of generator, although a small portable such as a Honda type may be able to be used if you have a balcony.
Output capacity
AC generators, regardless of size, are rated by the KVA (thousand volt amps, or just volt amps), NOT by how many watts or kilowatts that they put out. The reason for this is a much overlooked and misunderstood fact of AC circuits called "power factor". (PF)
Power factor is the ratio between "apparent power" (volt amps) and "real power" (watts or kilowatts). There are several reasons for this, but for here just accept that because of magnetic induction for one thing, there are going to be losses in any AC circuit. Or put another way, the voltage and amps in an AC circuit sine wave are NOT in phase. The voltage can be both leading OR lagging the current, but in this case with small generators the current will lag the voltage as it rises and falls. The usually accepted figure is 0.8 for calculations, but depending on the type of load the PF can be a lot less.
The formula to derive the watts then becomes: volts x amps x PF
So, if we have a generator rated at say 5.0 kVA, and the voltage is 220 volts, then by default the amps should be: 5,000 divided by 220 = 22.72 amps. Ignoring the PF, we could then say that as volts x amps = watts we have near enough to 5,000 watts, or 5.0 kilowatts.
But it cannot be ignored, as the AC formula is; volts x amps x PF
220 x 22.72 x 0.8 then becomes 3.998 or 4,000 watts, or 4.0 kilowatts.
The amps available then becomes: 4,000 divided by 220 volts = around 18 amps
A small parathesis here: on another post it has been stated that a quoted Honda generator is too small, followed by; "25 kVA." A decimal point mistake maybe, but 25 kVA is over 100amps, or just under 20 kW.
The next line quotes; 5,500 kVA! That is 5,500 thousand VA, which is 5 megawatts. I guess what is meant is that the generator is 5.5 kVA. The point is that it is important to understand the meaning of just what is being quoted. Close parathesis.
The following are some examples of generators listed in Thailand:
Generator-Gasoline Engine-HYUNDAI-Model-HD-GE-6800E-Power-55-kW-Blue - Thai Watsadu - Thai Watsadu
HD-GE-6800E HYUNDAI HD-6800E Gasoline Engine Generator 5.5 kW. 15 Hp (220V.| Electric Starter) - HereTools
The above is an example of how the generator is labelled. It shows 6,800 kVA, and correctly claimed as 5.5 kilowatts. (kW) And it appears to have 1 single full load outlet socket.
https://www.europa.co.th/th/product/451 ... -d5-silent
The above is an opposite example where it is shown as 5.5 kW, but if it is a 10 hp engine then it is probably around 6.8 kVA, which is in fact shown on other websites.
This one is a good example of why you need to shop around, both for price and capacity:
DAEWOO GDA8000E Gasoline Generator 7.5 kW. 17.0 HP (Start key) - EUROPA.co.th
I have no idea where the following are manufactured, but Atlas Copco machinery have a good reputation. Caveat Emptor here. Some generators made for the US market MAY have multiple voltage output options, such as 120 / 240 volts. Stay away from these as they can introduce a dangerous safety factor due to the internal windings centre tap method that is not designed for the MEN earthing system used here.
เครื่องปั่นไฟ Atlas Copco รุ่น P8000 ขนาด 6.5kW | Lazada.co.th
เครื่องปั่นไฟ Atlas Copco รุ่น P6000i ขนด 7kW | Lazada.co.th
The following is little more than a kid's toy. It is NOT designed for use as a backup, but rather just as a source for a couple of lights and fans. If that is all you want then it would probably do the job. Again, it is ambiguous as to just what its maximum output is, but more likely only 2.5 kW, and maybe 10 amps. To use this just plug in an extension cord with a multi outlet receptacle when needed for a few portable lights and fans. It MAY run a small refrigerator, more so if you have an inverter fridge. As the starting amps drawn by an induction motor can be up to 6 or 7 times the running amps, a small generator may "bog down", or stall, trying to start such a load.
HONDA เครื่องปั่นไฟเบนซิน EX3000CX R ปรับแรงดันไฟฟ้าอัตโนมัติ HONDA สีแดง | Lazada.co.th
Engine speeds: An engine driving an AC generator has to run at a set speed to obtain both the correct voltage and frequency. While the voltage can vary within certain limits, the frequency should not. The frequency of an AC generator is a function of the number of magnetic poles in the stator and the RPM of the rotor, and is referred to as "synchronous speed". The formula for 50 hz is: 50(hz) x 60(time in minutes) ÷ pairs of magnetic poles.
A 2 pole AC generator has 1 pair of poles, so: 50 x 60 = 3,000 ÷ 1 = 3,000 rpm
A 4 pole AC generator has 2 pairs of poles, so: 50 x 60 = 3,000 ÷ 2 = 1,500 rpm
and so on.
Just to prove it if you come from a 60Hz country:
A 2 pole AC generator has 1 pair of poles, so: 60 x 60 = 3,600 rpm ÷ 1 = 3,600 rpm
A 4 pole AC generator has 2 pairs of poles. so: 60 x 60 = 3,600 ÷ 2 = 1,800 rpm.
(The same formula applies to induction motors, except that with a motor a function called "slip" results in a plain induction motor running slightly below synchronous speed)
The consideration here is that a machine running at 3,000 rpm will make more noise and have more stress and wear on the engine as opposed to a machine running at 1,500 rpm.
As it is only going to be used as a backup, then it may not be a deciding factor.
There are now available small "invertor generators", although they seem to be scarce in Thailand and a lot more expensive if available. They have one big advantage in that the frequency is provided electronically by the invertor section and not dependant on rpm.
The engine runs at whatever speed that is required to satisfy the load; so, at low loads it may be running a lot slower and using less fuel. They also may run at anything up to 5,000 rpm! This feature may be attractive for running equipment that needs an accurate frequency supply.
There are reports floating around complaining that SOME backup generators will not run UPS power supplies, but from what I can determine it is big commercial type UPS units, not what you may have in a home system.
A related cause may be the type of voltage regulators (AVR) in use on small generators. There are several ways of regulating the voltage and some of the cheaper generators may not have the best option. It is not something that is really shown in the specs, so not really a way to find out except when it goes poof!
FUEL TYPES
The next consideration should be the fuel type of the engine. Most small generators have petrol engines, or if you must, "Benzine". However, this may not be the best choice. Several are advertised with diesel engines and one with an LPG conversion.
Petrol is a very volatile fuel and care needs to be taken with both its storage and use. It will deteriorate if stored for long periods of time and some loss due to evaporation will occur.
Some engine manufactures advise against using fuels with high proportions of ethanol, and in Thailand the only petrol available without ethanol is 95 octane, which may also not be recommended. On the plus side petrol engines tend to run a lot quieter with less vibration and service people tend to understand them better. They should be easier to start, especially if using a manual recoil rope pull system.
Diesel fuel is a lot safer to both store and use. It does not evaporate and with low proportions of ethanol or palm oil it is readily available. Some of the fuels available here have additives that claim to improve engine performance, or there are many after market additives that also can help maintain a diesel fuel system. On the down side a diesel engine is inherently more noisy and due to much higher compression can be harder to start, although almost all of them have electric starters. Vibration can be a problem but usually the frame is built to allow for this, along with noise insulation.
LPG generators are not common and seem to be restricted to smaller petrol engines, and some after market conversion kits. LPG is also volatile and as it is heavier than air any leaks will accumulate in low areas. It is a clean burning fuel and storage is not a problem. A 30 lb
tank as used for cooking should run a small generator for several days non stop.
General Safety
Safety in regard to exhaust emissions it is paramount with ALL types of combustion engines.
A suitable area out of the weather is also paramount, but it MUST have ventilation for both cooling and exhaust gases. If you have a swimming pool the pump house MAY be a suitable place, but a lot of the pool pump house's that I have seen in Thailand are not suitable to house pumps, never mind a generator!
On my own pump house, I have installed an industrial type fan that runs when the pumps are running. The fan needs to have a supply of fresh air which will tend to pressurise the area and force out both heat and fumes. A similar set up may be an option for a generator, and if built of brick also aid in stopping a lot of noise.
However you may choose to house a generator, it needs to be easily accessible, either with a removable "dog box" type of cover, or a walk in space. As Mr. Murphy is bound to ensure that the mains power will fail, both at night time and in the middle of a rain storm, a battery operated emergency light in the vicinity would be a good investment.
Electrical safety: Ah yes, TIT where electrical safety is two layers of PVC tape wrapped around several wires twisted together; in place of just one layer!
Yes, maybe an exaggeration, but if your house burns down the insurance assessor is going to be VERY interested in those extra wires hanging out of what remains of your main switchboard!
To start with the actual generator, it should be remembered that these machines produce a voltage and current just as lethal as the mains supply. DO NOT be led into believing that just because it is small it will not kill you!
The mains electrical distribution system used in Thailand is called a "MEN" system, which means "Multiple Earthed Neutral". This can become bit involved to define, but the basis is that a single phase 220 volt supply from the street into your house main switchboard consists of one active live conductor, and one neutral conductor; or a single phase and a neutral.
The neutral is "earthed" at what is called the "star point" of the street transformer windings.
If you visualise a "Y", then the star point is the centre of the "Y", and each of the "legs" is one single phase. 220 volts appear across the end of any one "leg" and the centre point, and therefore also above the ground or earth. OR your body if there is a fault, or you touch it!
The neutral is also SUPPOSED to be connected to earth at each consumer switchboard, hence the term "MEN"!
(If you have a 3 phase supply, then the end of each leg or phase is bought into your house along with the neutral (4 wires), and 380 volts appears between the ends of any 2 of the phases)
Depending on the age of your house and the electrical installation, it MAY or MAY NOT be wired with an earthing conductor. In recent years, and particularly from around 2013, new regulations have been instigated by the Thai authorities, and ALL new installations are SUPPOSED to be inspected before being connected to the grid. Under these regulations an earthing system has to be installed and comply with the rules, including testing to ensure that the earthing system provides a low resistance path to the ground.
The requirements are laid out in the following:
"รหัสมาตรฐาน EE 2001-56 มาตรฐานการติดตั้งทางไฟฟ้าสำหรับประเทศไทย พ.ศ. 2556" (Standard EE 2001-56 Electrical Installation Standard for Thailand, 2013)
Despite there being an English language index, there does not appear to be an English language edition of the rules.
https://eitstandard.com/%E0%B8%A1%E0%B8 ... 0%B8%9F-2/#
An effort is also being made to both train and licence electrical workers. There is now a department in Bangkok that sets exams and tests electrical workers before they can work on COMMERIAL installations. I guess that it will be a long time before this requirement trickles down to local house installers however!
https://www.dsd.go.th/standarD/Region/D ... tails/6054
As shown in the photo, they are now also trying to also instigate a conductor colour code standard.
It does not follow either British, American or Australian standards, but appears to be a bit of a combination. The biggest complaint that I have always had here is the use of black cables for live conductors. If all the other cables in an installation were a different colour it may work, but in most older installations both the live and neutral are black!
You may also find any other colour of the rainbow in use, depending on what Somchai had on hand!
That photo also shows up a local quirk in as much as the neutral conductor HAS to be connected to the earthing bar, or earth terminal strip, FIRST, rather than the neutral link bar. They then show a white / grey conductor linking the earth bar to what appears to be the neutral bar. The earthing bar is not insulated, whereas the neutral link is, so maybe it is an attempt to make sure that the incoming neutral is earthed, even if the wire link to the neutral bar is missing?
They are also specifying conductor sizes for various current loads:
I have to comment here that I think they are far too conservative with the above table.
Many different factors have to be considered when specifying amp capacities.
However, the insulation of SOME locally manufactured cables may be of a lower temperature rating, thereby justifying the lower ratings.
The following table shows some of these factors:
Electric Cable Size vs. Current Rating (engineeringtoolbox.com)
I cannot find it, but buried away somewhere in those regulations there has to be a rule concerning the switching of the neutral. In all jurisdiction that I have worked under the switching of ANY neutral is strictly verboten! Maybe that is the reason for connecting the incoming neutral directly to the earthing link?
That being the case then there are thousands of old installations in Thailand that have a double pole main switch installed that switches the neutral along with the live conductor!
As it is not practical to change all of them, I guess that the grandfather rule will apply!
Not sure just what the case may be after all the grandfathers have passed away!
If your installation does not have any earthing system, I would strongly recommend that you have one fitted. Even if the installation does not have an earthing conductor at each outlet or hardwired appliance, it will at least provide some protection from surges, lightning strike and other stray voltage's floating around. An RCD breaker will work without an earth connection, so is also a good investment. Be aware that ELCB's DO require an earth and are no longer manufactured.
Rather than clog this up any further, the following has a good explanation of the different types:
What is the difference between MCB, MCCB, ELCB, and RCCB (electrical-engineering-portal.com)
Why it is Important to have an RCCB in a Distribution Board? - CS Electric
As stated previously; all generators are not created equal.
It is absolutely essential that a generator that you wish to connect to an existing installation should have a completely "floating" type of output. It should not have any form of RCD built in protection, as it will conflict with any such device already existing in the installation.
The generator neutral must NOT be connected to any earth terminal on the machine output. Most of them are correct, but it should be checked. Just the 220 volts and the "neutral" should be connected from the generator windings, through some form of protection device, usually a suitably rated magnetic (MCB) breaker. There may be one common breaker if more than one outlet socket, or 2 smaller breakers. Some even have both, one labelled main switch.
All of the metal parts of the generator should be bonded together. If the engine for example has resilient rubber mounts, then there should be a bonding wire connected to the metal part of the frame. The generator housing and the fuel tank should also be bonded to the frame.
There MAY or MAY NOT be a prominent "EARTH" terminal somewhere on the frame.
There is much confusion and argument concerning any such terminal! The rules vary with each jurisdiction, and also depend on the type of generator. Earthing a dual voltage generator WILL introduce a potentially dangerous situation. Unless your generator is mounted on 4 rubber wheels, the very fact that it sitting on the ground constitutes an "earth" of the frame.
The danger of connecting the generator via a 3 conductor cable to your house introduces a potential feedback loop from an out of balance neutral in your main switchboard. If the house installation is correct then that connection automatically provides a safe earth via the neutral.
The only conductor that is needed is the "live" conductor from the generator, as long as the "neutral" from the generator is NOT connected to earth, then it will be safe.
Technically; it is not a "neutral" but just line 2 (L2) of the generator.
An exception to the above is that if you are just running the generator as a standalone, NOT connecting to the house, just plugging in an appliance, THEN it should have an earth stake fitted.
The next consideration is: how to instal wiring from the generator to your house switchboard.
Firstly, by whatever means you use it should not be "hard wired". Most generators have 2 socket outlets, short circuit protected as previously mentioned. SOME units also have a single socket outlet which is capable of carrying the full load output, some may have 2 outlets rated at about half the output of the machine. If not already fitted I strongly suggest that you have an extra outlet fitted fed through its own MCB. Preferably, it should be of the blue or red industrial type CEE socket and plug. These have weather proof cover for when not in use and some a securing locking ring when a plug is inserted. They are polarised and can only be inserted in the correct orientation. A 32 amp plug and socket should be used.
Both Thaiwatsadu and Global House stock these fittings.
RS Components also list them, but the last time that I tried to deal with them here I ended up having to threaten them with a Lawyer!
V.E.G Blue RG-013 Medium Connector Plug |GlobalHouse
V.E.G Wall Plug RG-S113 Blue |GlobalHouse
2CMA193122R1000 232RS6 | ABB, Easy & Safe IP44 Blue Wall Mount 2P+E Right Angle Industrial Power Socket, Rated At 32.0A, 230.0 V | RS Components (rs-online.com)
Power Plugs - WNJ Rungroj Electric Co., Ltd. (WNJ) ตัวแทนจำหน่ายอุปกรณ์ไฟฟ้า ABB
MENNEKES Industrial Plug Power Plug - Rubicon Engineering Co.,Ltd. Cheap Delivery Nationwide : Inspired by LnwShop.com (rbc-rubicon.com)
CABLE
ALL cable is expensive!
If you can find some, a flexible multistrand 2 conductor PVC cable SHOULD be used between the generator and wherever the entry point is located on your house. As previously, the connection to the generator should be via a polarised female outlet socket. The cable will need to have a matching male plug fitted. I prefer to use a plug and socket rated at 32 amps. To match that a minimum 6 sq mm conductor is required, or even better, 10 sq mm.
Use only 2 conductor cable, ensuring that the live conductor (usually marked as L1) from the generator will later match whatever you are using to connect to inside the house.
The following place advertises that they will cut cable to the length required.
https://www.lazada.co.th/products/vct-6 ... 82954.html
ENTRY POINT TO THE HOUSE
To do this correctly the connection to the house SHOULD be via an entry socket. These sockets are REVERSE configuration, that is they have MALE pins. It HAS to be this way to ENSURE that the live flexible cable plug from the generator is therefore FEMALE, and there is no possibility of bare live terminal pins being exposed. The male exposed pins in the inlet socket can ONLY be live when the transfer switch is in the generator position and the generator running and plugged in.
https://new.abb.com/products/2CMA193315R1000/232bs9
https://www.cef.co.uk/catalogue/product ... nt=dynamic
Doing it this way ensures that when not in use, OR when you need to move the generator, the flexible cable can be removed without disconnecting any wiring.
If your budget does not run to the expense of the above detailed socket, then an alternative is to mount a weatherproof PVC box on the wall. These boxes are cheap and available in a multitude of sizes, some have hinged doors, so an isolating switch could also be included.
ตู้ไฟ ตู้กันน้ำพลาสติก NANO (NANO-102W) | Lazada.co.th
ABS High-end Quality IP67 Waterproof Electrical Junction Box ABS plastic Enclosure Case Outdoor Distribution box | Lazada.co.th
Suitable cable glands should be used for entries.
SIERWU 10Pcs New White Black Nylon Plastic 3-6.5mm Diameter IP68 Waterproof Wire Connector PG7 PG9 PG11 PG13.5 PG16 PG19 Cable Gland | Lazada.co.th
Or a slot could be made in the bottom of a large type enclosure and the flexible cable stored in there when not in use. It all depends a bit on each individual situation.
CABLE FROM ENTRY POINT TO HOUSE SWITCHBOARD
Even if your house main switchboard is close to where the entry point of the generator supply is, you are going to need some rated building cable. This cable MUST be at least 6 sq mm, and depending on the length, 10 sq mm should be considered. DO NOT skimp on this cable inside your house! Again, only 2 conductor cable is needed, but most of this type of cable comes with an earthing conductor. Do the Thai thing and just cut the end of the earth conductor off if that being the case.
https://www.lazada.co.th/products/thai- ... g&search=1
Just like PVC boxes, there is a multitude of available building cable, and most of the bigger suppliers will cut it to required length.
TRANSFER SWITCH
We now come to the most important component of a standby power system.
To start off with, this switch should be close too or adjacent to the main switchboard, or "consumer unit" in modern speak. Regardless of where you mount it, the incoming main live supply phase cable from the street has to be moved from the consumer unit main breaker, to one leg of the transfer switch.
WARNING: The Thai regulation colour code for single phase is the same as the USA NEC code: Live-black; Neutral-grey / white; Earth-green, sometimes with a yellow stripe.
DO NOT take this for granted, CHECK test which conductor is actually live!
A small test screw driver such as the following will suffice:
STANLEY Screwdrivers Mains Tester #66-119 | Lazada.co.th
NOTE: DO NOT use this cheap device for ANY other purpose, it can be a bloody dangerous trap!
You may find that this wire is not long enough, or cannot be rerouted, to reach the new transfer switch, in which case a wire will have to be led into a small junction box and a new short extension section of cable installed which is then run to the transfer switch. Or, if there is space in the existing switchboard, it may be possible to connect an extension wire there. It must be done with a suitable screwed connector, be well insulated and MUST be the same sq mm as the existing wire. After connecting to the transfer switch, a similar sized length and gauge of wire is then required to return to the consumer unit main breaker or MCB.
NOTE: ONLY the active live phase wire needs to be moved! Remember the early part of this report where it is stated that the main "neutral" MUST NOT be switched, and MUST be first connected to the consumer unit earthing bar link. (this connecting to the earthing bar FIRST is part of the new Thai regulations, as in most other jurisdictions the neutral is connected to the neutral link first, which in turn is wire connected to the earthing bar. (the end result being the same!). It is also a very good safety factor.
The above now leads to a dilemma. It is very likely that you will find that your consumer unit has a double pole main breaker or MCB. To comply with the regulations this breaker SHOULD be replaced with a single pole breaker, and the incoming main neutral moved, as per the rules, to the earthing bar link, which it may or may not have! You may find that the main breaker is some form of ELCB or RCD which requires that both the active and neutral be connected to it, in which case it should be replaced.
Whatever is already installed will continue to function, with just the live conductor now coming from the transfer switch from either the mains or generator, BUT it may not be safe. The generator "neutral" will have to be connected directly to the existing neutral link bar after passing through the transfer switch.
Unless it is some form of RCD a double pole main breaker should still function safely with just one "leg" connected, but if the mains neutral is connected to the input side it will have to be moved to the neutral bar link. If it is an RCD type switch, then it will have to be replaced. RCD type safety switches should only be installed in outgoing load circuits.
The following link to Hager also has a further link to a circuit diagram as a PDF file that can downloaded and printed out:
https://www.hagerelectro.com.au/e-catal ... s/3483.htm
Depending on the age of your consumer unit it may be time to consider replacing it, if not able to modify it. They are not that expensive, and there are many options available. It would also be a good time to install an earthing system, and perhaps some safety RCD breaker circuits for such things as hot water shower heaters. If replacing an existing breaker with some form of RCD device there will probably not be enough space on your existing consumer unit.
NOTE: the new neutral rule applies to the MAIN incoming neutral, and NOT to a neutral passing through any RCD.
Transfer Switch Options
It is absolutely IMPERATIVE that whatever type of transfer switch that you install isolates the main incoming live phase supply! This is to ensure that no voltage can be "fed back" to the street supply while connected to the generator.
It also should be of the "break before make" configuration; meaning that whichever supply is being used it will fully disconnect BEFORE making a connection in the other direction.
If the switch uses contactors, then they must be both mechanically and electrically interlocked so that it is only possible for one of them to close at one time.
For this main reason I personally prefer to use a manual 3 position switch. The following is just an example of the type as it has an "off" position:
Harmony_K_K63E003WP.pdf (rs-online.com)
The Hager link above also shows a good switch.
The transfer switch must be rated at the same amps as your existing main switch and have at least 2 poles, although most of them will have 3 poles. For most houses the main switch will probably be rated at 63 amps. A big consideration will also be how you intend to mount the transfer switch. It will need to be in an enclosure of some description, and better if it can be operated without opening the enclosure.
Automatic (ATS) or Manual Transfer.
Unless you have some special needs such as being partly disabled, or need a reliable instant supply for medical equipment, I cannot see the need for an automatic transfer arrangement.
And don’t forget that even if the system starts and transfers automatically, it will still need to be stopped manually once the normal supply is restored. Just as an aside, some form of indication, such as a light or audible signal, should be installed to indicate when the mains supply is again available.
If you do decide that an automatic system is the best for you, then you will also be limited in your choice of generators to those with diesel engines. That in itself is not a bad thing, but may limit the available choice.
Although not impossible to do, a petrol engine will require at least an ignition switch. and most probably some form of choke to start it. Providing that it has a good battery, a diesel engine only needs a signal to the starter motor to start.
There are nearly as many different transfer switches as there are 7-11's in Thailand!
Some are manual only, some selectable manual or automatic, some have provision for remote transfer switching, the combination appears to be endless! As an automatic switch is more complex, it therefore follows that there are more components that can fail.
I cannot recommend any, as I have not used any of them, but point out that some of them will have magnetic coils in them as they are contactors, which may mean that in the "normal" position the coil MAY be energised and therefore a potential burn out area. You need to research each one fully and select one that suits your needs. The only REAL advice is to make sure that the amp rating is at least the same as your main switchboard breaker, as the normal load will pass through the transfer switch.
Dual-Power Automatic Transfer Switch 2P 100A Household 35mm Rail Installation | Lazada.co.th
TOMZN Single Phase Din Rail ATS Dual Power Automatic Transfer Electrical Selector Switches Uninterrupted 2P 63A 100A 125A | Lazada.co.th
ATS CSQ เอทีเอสสวิทช์ สวิตช์เปลี่ยนแหล่งจ่ายไฟฟ้าอัตโนมัติ (CSQ Automatic Transfer Switch) 63A 220V 1 phase | Lazada.co.th
Applegreen ตู้ ATS Automatic transfer switch พร้อมใช้งาน 2P 63A Single phase สวิทช์สลับแหล่งจ่ายไฟอัตโนมัติ ระบบโซล่าเซลล์ พลังงานทดแทน ไฟฟ้าสำรอง | Lazada.co.th
Changeover Switch Features (hagerelectro.com.au)
https://www.southeastthailand.co.th/contact.php (Hager agent)
If you want to go a bit bigger the following is made in Thailand, so spare parts should be available:
https://www.heretools.com/th/product/79 ... A-kwm-7500
https://www.heretools.com/th/product/78 ... wm7500-new
https://www.heretools.com/th/product/71 ... wel-8500ea
Under and over voltage protection:
On many occasions the mains supply voltage may drop substantially. Anything from the normal 220 volts down to around 180 volts or less sometimes. This condition is called a "brown out", rather than a "black out". It is mostly caused by the loss of 1 phase coming from the street transformer. The only indication that you may have is that the lights go dim, or your computer switches to a UPS or battery with a laptop. Sometimes, the smoke may escape from whatever happens to be plugged in!
Because of the way the street transformer is connected internally (star connection), there is still voltage being produced by the windings, but one phase is not carrying the correct voltage to your house. Your neighbour's house may be connected to a different one of the three phases of the street supply, and will not be affected with their lights still on.
In most cases it is a blown fuse somewhere feeding the overhead distribution wire, and not the transformer per se. If the complete transformer fails it usually goes with a big bang resulting in a complete blackout!
(this mostly happens if you live around Bangsapan
)
There is now available a small device called a "voltage sensing relay". Their function is to continuously monitor the AC voltage, and disconnect at a preset point, either too low, or too high. Most can also be set to a maximum amp load.
https://www.lazada.co.th/products/volta ... ml?&search
There are a several ways that this type of device can be used. As the above example is rated at 63 amps it could be wired up to disconnect the complete consumer unit. It could be wired up just to disconnect one sensitive load circuit, such as a refrigerator or computer.
It could also be mounted in a small PVC enclosure with a plug and socket and therefore portable and used wherever sensitive equipment is plugged in.
There are many available, just search the internet.
If you have a generator with an electric starter, then a small battery will be required. The generator wil probably have a built in battery charger, but that will only work when the engine is running.
To maintain the battery a small "smart charger" should be used. They are designed to maintain a battery, especially a battery that is used on a standby starting system.
The best type is a "CTEK". but be aware that they are not cheap.
CTEK Intelligent Battery Charger XS 0.8 | Lazada.co.th
The following one is a FAKE!
Multi MXS 5.0 12V Car Battery Smart Trickle Charger & FREE INDICATOR 56-382 EU plug | Lazada.co.th
CAVEAT EMPTOR
While a standby generator is a simple circuit, it is this very fact that can, and does, lead to complacency and compromised safety.
While every care has been taken with the writing of this report, the author accepts no responsibility for the topicality, correctness, completeness or quality of the information provided.
It is very simple: if you do not know WTF you are doing, DON’T DO IT!
Or use one of these:
Hand Crank Generator Portable Device - Life Changing Products (lcpshop.net)
This subject could do with a bit more in depth information for anybody interested.
For those that do not know me I have spent a big part of my working life repairing, operating and maintaining a multitude of different types of generators, along with their engines and distribution systems. Right from a 32 volt DC generator as a 10 year old on the farm that I grew up on, through a 5 year apprenticeship in a rewinding and repair shop, on to serving as both a ships electrician and later the chief engineer on both AC and DC systems up to 6 kV on oil rigs for more years than I want to remember!
(no Sherlock, NOT on the Titanic)
Oh, and along the way I owned and flew helicopters for several years, one of which had a
28 volt combined starter / generator controlled by a carbon pile voltage regulator!
- shorts.jpg (86.43 KiB) Viewed 5140 times
All generators are not created equal, and in Thailand there seems to be an endless and confusing array of choices. However, as this is about small portable AC generators suitable for use as a backup home supply, I will try and stick with them.
It also refers to 220 volt 50Hz single phase, if you have a 3 phase supply it is still possible but different equipment will be required.
It also assumes that you own the house, as I doubt any rental landlord would allow a permanent installation. If you live in a Condo, you will probably be banned from ANY type of generator, although a small portable such as a Honda type may be able to be used if you have a balcony.
Output capacity
AC generators, regardless of size, are rated by the KVA (thousand volt amps, or just volt amps), NOT by how many watts or kilowatts that they put out. The reason for this is a much overlooked and misunderstood fact of AC circuits called "power factor". (PF)
Power factor is the ratio between "apparent power" (volt amps) and "real power" (watts or kilowatts). There are several reasons for this, but for here just accept that because of magnetic induction for one thing, there are going to be losses in any AC circuit. Or put another way, the voltage and amps in an AC circuit sine wave are NOT in phase. The voltage can be both leading OR lagging the current, but in this case with small generators the current will lag the voltage as it rises and falls. The usually accepted figure is 0.8 for calculations, but depending on the type of load the PF can be a lot less.
The formula to derive the watts then becomes: volts x amps x PF
So, if we have a generator rated at say 5.0 kVA, and the voltage is 220 volts, then by default the amps should be: 5,000 divided by 220 = 22.72 amps. Ignoring the PF, we could then say that as volts x amps = watts we have near enough to 5,000 watts, or 5.0 kilowatts.
But it cannot be ignored, as the AC formula is; volts x amps x PF
220 x 22.72 x 0.8 then becomes 3.998 or 4,000 watts, or 4.0 kilowatts.
The amps available then becomes: 4,000 divided by 220 volts = around 18 amps
A small parathesis here: on another post it has been stated that a quoted Honda generator is too small, followed by; "25 kVA." A decimal point mistake maybe, but 25 kVA is over 100amps, or just under 20 kW.
The next line quotes; 5,500 kVA! That is 5,500 thousand VA, which is 5 megawatts. I guess what is meant is that the generator is 5.5 kVA. The point is that it is important to understand the meaning of just what is being quoted. Close parathesis.
The following are some examples of generators listed in Thailand:
Generator-Gasoline Engine-HYUNDAI-Model-HD-GE-6800E-Power-55-kW-Blue - Thai Watsadu - Thai Watsadu
HD-GE-6800E HYUNDAI HD-6800E Gasoline Engine Generator 5.5 kW. 15 Hp (220V.| Electric Starter) - HereTools
The above is an example of how the generator is labelled. It shows 6,800 kVA, and correctly claimed as 5.5 kilowatts. (kW) And it appears to have 1 single full load outlet socket.
https://www.europa.co.th/th/product/451 ... -d5-silent
The above is an opposite example where it is shown as 5.5 kW, but if it is a 10 hp engine then it is probably around 6.8 kVA, which is in fact shown on other websites.
This one is a good example of why you need to shop around, both for price and capacity:
DAEWOO GDA8000E Gasoline Generator 7.5 kW. 17.0 HP (Start key) - EUROPA.co.th
I have no idea where the following are manufactured, but Atlas Copco machinery have a good reputation. Caveat Emptor here. Some generators made for the US market MAY have multiple voltage output options, such as 120 / 240 volts. Stay away from these as they can introduce a dangerous safety factor due to the internal windings centre tap method that is not designed for the MEN earthing system used here.
เครื่องปั่นไฟ Atlas Copco รุ่น P8000 ขนาด 6.5kW | Lazada.co.th
เครื่องปั่นไฟ Atlas Copco รุ่น P6000i ขนด 7kW | Lazada.co.th
The following is little more than a kid's toy. It is NOT designed for use as a backup, but rather just as a source for a couple of lights and fans. If that is all you want then it would probably do the job. Again, it is ambiguous as to just what its maximum output is, but more likely only 2.5 kW, and maybe 10 amps. To use this just plug in an extension cord with a multi outlet receptacle when needed for a few portable lights and fans. It MAY run a small refrigerator, more so if you have an inverter fridge. As the starting amps drawn by an induction motor can be up to 6 or 7 times the running amps, a small generator may "bog down", or stall, trying to start such a load.
HONDA เครื่องปั่นไฟเบนซิน EX3000CX R ปรับแรงดันไฟฟ้าอัตโนมัติ HONDA สีแดง | Lazada.co.th
Engine speeds: An engine driving an AC generator has to run at a set speed to obtain both the correct voltage and frequency. While the voltage can vary within certain limits, the frequency should not. The frequency of an AC generator is a function of the number of magnetic poles in the stator and the RPM of the rotor, and is referred to as "synchronous speed". The formula for 50 hz is: 50(hz) x 60(time in minutes) ÷ pairs of magnetic poles.
A 2 pole AC generator has 1 pair of poles, so: 50 x 60 = 3,000 ÷ 1 = 3,000 rpm
A 4 pole AC generator has 2 pairs of poles, so: 50 x 60 = 3,000 ÷ 2 = 1,500 rpm
and so on.
Just to prove it if you come from a 60Hz country:
A 2 pole AC generator has 1 pair of poles, so: 60 x 60 = 3,600 rpm ÷ 1 = 3,600 rpm
A 4 pole AC generator has 2 pairs of poles. so: 60 x 60 = 3,600 ÷ 2 = 1,800 rpm.
(The same formula applies to induction motors, except that with a motor a function called "slip" results in a plain induction motor running slightly below synchronous speed)
The consideration here is that a machine running at 3,000 rpm will make more noise and have more stress and wear on the engine as opposed to a machine running at 1,500 rpm.
As it is only going to be used as a backup, then it may not be a deciding factor.
There are now available small "invertor generators", although they seem to be scarce in Thailand and a lot more expensive if available. They have one big advantage in that the frequency is provided electronically by the invertor section and not dependant on rpm.
The engine runs at whatever speed that is required to satisfy the load; so, at low loads it may be running a lot slower and using less fuel. They also may run at anything up to 5,000 rpm! This feature may be attractive for running equipment that needs an accurate frequency supply.
There are reports floating around complaining that SOME backup generators will not run UPS power supplies, but from what I can determine it is big commercial type UPS units, not what you may have in a home system.
A related cause may be the type of voltage regulators (AVR) in use on small generators. There are several ways of regulating the voltage and some of the cheaper generators may not have the best option. It is not something that is really shown in the specs, so not really a way to find out except when it goes poof!
FUEL TYPES
The next consideration should be the fuel type of the engine. Most small generators have petrol engines, or if you must, "Benzine". However, this may not be the best choice. Several are advertised with diesel engines and one with an LPG conversion.
Petrol is a very volatile fuel and care needs to be taken with both its storage and use. It will deteriorate if stored for long periods of time and some loss due to evaporation will occur.
Some engine manufactures advise against using fuels with high proportions of ethanol, and in Thailand the only petrol available without ethanol is 95 octane, which may also not be recommended. On the plus side petrol engines tend to run a lot quieter with less vibration and service people tend to understand them better. They should be easier to start, especially if using a manual recoil rope pull system.
Diesel fuel is a lot safer to both store and use. It does not evaporate and with low proportions of ethanol or palm oil it is readily available. Some of the fuels available here have additives that claim to improve engine performance, or there are many after market additives that also can help maintain a diesel fuel system. On the down side a diesel engine is inherently more noisy and due to much higher compression can be harder to start, although almost all of them have electric starters. Vibration can be a problem but usually the frame is built to allow for this, along with noise insulation.
LPG generators are not common and seem to be restricted to smaller petrol engines, and some after market conversion kits. LPG is also volatile and as it is heavier than air any leaks will accumulate in low areas. It is a clean burning fuel and storage is not a problem. A 30 lb
tank as used for cooking should run a small generator for several days non stop.
General Safety
Safety in regard to exhaust emissions it is paramount with ALL types of combustion engines.
A suitable area out of the weather is also paramount, but it MUST have ventilation for both cooling and exhaust gases. If you have a swimming pool the pump house MAY be a suitable place, but a lot of the pool pump house's that I have seen in Thailand are not suitable to house pumps, never mind a generator!
On my own pump house, I have installed an industrial type fan that runs when the pumps are running. The fan needs to have a supply of fresh air which will tend to pressurise the area and force out both heat and fumes. A similar set up may be an option for a generator, and if built of brick also aid in stopping a lot of noise.
However you may choose to house a generator, it needs to be easily accessible, either with a removable "dog box" type of cover, or a walk in space. As Mr. Murphy is bound to ensure that the mains power will fail, both at night time and in the middle of a rain storm, a battery operated emergency light in the vicinity would be a good investment.
Electrical safety: Ah yes, TIT where electrical safety is two layers of PVC tape wrapped around several wires twisted together; in place of just one layer!
Yes, maybe an exaggeration, but if your house burns down the insurance assessor is going to be VERY interested in those extra wires hanging out of what remains of your main switchboard!
To start with the actual generator, it should be remembered that these machines produce a voltage and current just as lethal as the mains supply. DO NOT be led into believing that just because it is small it will not kill you!
The mains electrical distribution system used in Thailand is called a "MEN" system, which means "Multiple Earthed Neutral". This can become bit involved to define, but the basis is that a single phase 220 volt supply from the street into your house main switchboard consists of one active live conductor, and one neutral conductor; or a single phase and a neutral.
The neutral is "earthed" at what is called the "star point" of the street transformer windings.
If you visualise a "Y", then the star point is the centre of the "Y", and each of the "legs" is one single phase. 220 volts appear across the end of any one "leg" and the centre point, and therefore also above the ground or earth. OR your body if there is a fault, or you touch it!
The neutral is also SUPPOSED to be connected to earth at each consumer switchboard, hence the term "MEN"!
(If you have a 3 phase supply, then the end of each leg or phase is bought into your house along with the neutral (4 wires), and 380 volts appears between the ends of any 2 of the phases)
Depending on the age of your house and the electrical installation, it MAY or MAY NOT be wired with an earthing conductor. In recent years, and particularly from around 2013, new regulations have been instigated by the Thai authorities, and ALL new installations are SUPPOSED to be inspected before being connected to the grid. Under these regulations an earthing system has to be installed and comply with the rules, including testing to ensure that the earthing system provides a low resistance path to the ground.
- Thai Earthing System
- Thai earthing system.jpg (163.44 KiB) Viewed 5140 times
"รหัสมาตรฐาน EE 2001-56 มาตรฐานการติดตั้งทางไฟฟ้าสำหรับประเทศไทย พ.ศ. 2556" (Standard EE 2001-56 Electrical Installation Standard for Thailand, 2013)
Despite there being an English language index, there does not appear to be an English language edition of the rules.
https://eitstandard.com/%E0%B8%A1%E0%B8 ... 0%B8%9F-2/#
An effort is also being made to both train and licence electrical workers. There is now a department in Bangkok that sets exams and tests electrical workers before they can work on COMMERIAL installations. I guess that it will be a long time before this requirement trickles down to local house installers however!
https://www.dsd.go.th/standarD/Region/D ... tails/6054
- 3 phase example.jpg (140 KiB) Viewed 5140 times
It does not follow either British, American or Australian standards, but appears to be a bit of a combination. The biggest complaint that I have always had here is the use of black cables for live conductors. If all the other cables in an installation were a different colour it may work, but in most older installations both the live and neutral are black!
You may also find any other colour of the rainbow in use, depending on what Somchai had on hand!
That photo also shows up a local quirk in as much as the neutral conductor HAS to be connected to the earthing bar, or earth terminal strip, FIRST, rather than the neutral link bar. They then show a white / grey conductor linking the earth bar to what appears to be the neutral bar. The earthing bar is not insulated, whereas the neutral link is, so maybe it is an attempt to make sure that the incoming neutral is earthed, even if the wire link to the neutral bar is missing?
They are also specifying conductor sizes for various current loads:
I have to comment here that I think they are far too conservative with the above table.
Many different factors have to be considered when specifying amp capacities.
However, the insulation of SOME locally manufactured cables may be of a lower temperature rating, thereby justifying the lower ratings.
The following table shows some of these factors:
Electric Cable Size vs. Current Rating (engineeringtoolbox.com)
I cannot find it, but buried away somewhere in those regulations there has to be a rule concerning the switching of the neutral. In all jurisdiction that I have worked under the switching of ANY neutral is strictly verboten! Maybe that is the reason for connecting the incoming neutral directly to the earthing link?
That being the case then there are thousands of old installations in Thailand that have a double pole main switch installed that switches the neutral along with the live conductor!
As it is not practical to change all of them, I guess that the grandfather rule will apply!
Not sure just what the case may be after all the grandfathers have passed away!
If your installation does not have any earthing system, I would strongly recommend that you have one fitted. Even if the installation does not have an earthing conductor at each outlet or hardwired appliance, it will at least provide some protection from surges, lightning strike and other stray voltage's floating around. An RCD breaker will work without an earth connection, so is also a good investment. Be aware that ELCB's DO require an earth and are no longer manufactured.
Rather than clog this up any further, the following has a good explanation of the different types:
What is the difference between MCB, MCCB, ELCB, and RCCB (electrical-engineering-portal.com)
Why it is Important to have an RCCB in a Distribution Board? - CS Electric
As stated previously; all generators are not created equal.
It is absolutely essential that a generator that you wish to connect to an existing installation should have a completely "floating" type of output. It should not have any form of RCD built in protection, as it will conflict with any such device already existing in the installation.
The generator neutral must NOT be connected to any earth terminal on the machine output. Most of them are correct, but it should be checked. Just the 220 volts and the "neutral" should be connected from the generator windings, through some form of protection device, usually a suitably rated magnetic (MCB) breaker. There may be one common breaker if more than one outlet socket, or 2 smaller breakers. Some even have both, one labelled main switch.
All of the metal parts of the generator should be bonded together. If the engine for example has resilient rubber mounts, then there should be a bonding wire connected to the metal part of the frame. The generator housing and the fuel tank should also be bonded to the frame.
There MAY or MAY NOT be a prominent "EARTH" terminal somewhere on the frame.
There is much confusion and argument concerning any such terminal! The rules vary with each jurisdiction, and also depend on the type of generator. Earthing a dual voltage generator WILL introduce a potentially dangerous situation. Unless your generator is mounted on 4 rubber wheels, the very fact that it sitting on the ground constitutes an "earth" of the frame.
The danger of connecting the generator via a 3 conductor cable to your house introduces a potential feedback loop from an out of balance neutral in your main switchboard. If the house installation is correct then that connection automatically provides a safe earth via the neutral.
The only conductor that is needed is the "live" conductor from the generator, as long as the "neutral" from the generator is NOT connected to earth, then it will be safe.
Technically; it is not a "neutral" but just line 2 (L2) of the generator.
An exception to the above is that if you are just running the generator as a standalone, NOT connecting to the house, just plugging in an appliance, THEN it should have an earth stake fitted.
The next consideration is: how to instal wiring from the generator to your house switchboard.
Firstly, by whatever means you use it should not be "hard wired". Most generators have 2 socket outlets, short circuit protected as previously mentioned. SOME units also have a single socket outlet which is capable of carrying the full load output, some may have 2 outlets rated at about half the output of the machine. If not already fitted I strongly suggest that you have an extra outlet fitted fed through its own MCB. Preferably, it should be of the blue or red industrial type CEE socket and plug. These have weather proof cover for when not in use and some a securing locking ring when a plug is inserted. They are polarised and can only be inserted in the correct orientation. A 32 amp plug and socket should be used.
Both Thaiwatsadu and Global House stock these fittings.
RS Components also list them, but the last time that I tried to deal with them here I ended up having to threaten them with a Lawyer!
V.E.G Blue RG-013 Medium Connector Plug |GlobalHouse
V.E.G Wall Plug RG-S113 Blue |GlobalHouse
2CMA193122R1000 232RS6 | ABB, Easy & Safe IP44 Blue Wall Mount 2P+E Right Angle Industrial Power Socket, Rated At 32.0A, 230.0 V | RS Components (rs-online.com)
Power Plugs - WNJ Rungroj Electric Co., Ltd. (WNJ) ตัวแทนจำหน่ายอุปกรณ์ไฟฟ้า ABB
MENNEKES Industrial Plug Power Plug - Rubicon Engineering Co.,Ltd. Cheap Delivery Nationwide : Inspired by LnwShop.com (rbc-rubicon.com)
- featured-portable-generators.jpg (57.11 KiB) Viewed 5140 times
ALL cable is expensive!
If you can find some, a flexible multistrand 2 conductor PVC cable SHOULD be used between the generator and wherever the entry point is located on your house. As previously, the connection to the generator should be via a polarised female outlet socket. The cable will need to have a matching male plug fitted. I prefer to use a plug and socket rated at 32 amps. To match that a minimum 6 sq mm conductor is required, or even better, 10 sq mm.
Use only 2 conductor cable, ensuring that the live conductor (usually marked as L1) from the generator will later match whatever you are using to connect to inside the house.
The following place advertises that they will cut cable to the length required.
https://www.lazada.co.th/products/vct-6 ... 82954.html
ENTRY POINT TO THE HOUSE
To do this correctly the connection to the house SHOULD be via an entry socket. These sockets are REVERSE configuration, that is they have MALE pins. It HAS to be this way to ENSURE that the live flexible cable plug from the generator is therefore FEMALE, and there is no possibility of bare live terminal pins being exposed. The male exposed pins in the inlet socket can ONLY be live when the transfer switch is in the generator position and the generator running and plugged in.
https://new.abb.com/products/2CMA193315R1000/232bs9
https://www.cef.co.uk/catalogue/product ... nt=dynamic
Doing it this way ensures that when not in use, OR when you need to move the generator, the flexible cable can be removed without disconnecting any wiring.
If your budget does not run to the expense of the above detailed socket, then an alternative is to mount a weatherproof PVC box on the wall. These boxes are cheap and available in a multitude of sizes, some have hinged doors, so an isolating switch could also be included.
ตู้ไฟ ตู้กันน้ำพลาสติก NANO (NANO-102W) | Lazada.co.th
ABS High-end Quality IP67 Waterproof Electrical Junction Box ABS plastic Enclosure Case Outdoor Distribution box | Lazada.co.th
Suitable cable glands should be used for entries.
SIERWU 10Pcs New White Black Nylon Plastic 3-6.5mm Diameter IP68 Waterproof Wire Connector PG7 PG9 PG11 PG13.5 PG16 PG19 Cable Gland | Lazada.co.th
Or a slot could be made in the bottom of a large type enclosure and the flexible cable stored in there when not in use. It all depends a bit on each individual situation.
CABLE FROM ENTRY POINT TO HOUSE SWITCHBOARD
Even if your house main switchboard is close to where the entry point of the generator supply is, you are going to need some rated building cable. This cable MUST be at least 6 sq mm, and depending on the length, 10 sq mm should be considered. DO NOT skimp on this cable inside your house! Again, only 2 conductor cable is needed, but most of this type of cable comes with an earthing conductor. Do the Thai thing and just cut the end of the earth conductor off if that being the case.
https://www.lazada.co.th/products/thai- ... g&search=1
Just like PVC boxes, there is a multitude of available building cable, and most of the bigger suppliers will cut it to required length.
TRANSFER SWITCH
We now come to the most important component of a standby power system.
To start off with, this switch should be close too or adjacent to the main switchboard, or "consumer unit" in modern speak. Regardless of where you mount it, the incoming main live supply phase cable from the street has to be moved from the consumer unit main breaker, to one leg of the transfer switch.
WARNING: The Thai regulation colour code for single phase is the same as the USA NEC code: Live-black; Neutral-grey / white; Earth-green, sometimes with a yellow stripe.
DO NOT take this for granted, CHECK test which conductor is actually live!
A small test screw driver such as the following will suffice:
STANLEY Screwdrivers Mains Tester #66-119 | Lazada.co.th
NOTE: DO NOT use this cheap device for ANY other purpose, it can be a bloody dangerous trap!
You may find that this wire is not long enough, or cannot be rerouted, to reach the new transfer switch, in which case a wire will have to be led into a small junction box and a new short extension section of cable installed which is then run to the transfer switch. Or, if there is space in the existing switchboard, it may be possible to connect an extension wire there. It must be done with a suitable screwed connector, be well insulated and MUST be the same sq mm as the existing wire. After connecting to the transfer switch, a similar sized length and gauge of wire is then required to return to the consumer unit main breaker or MCB.
NOTE: ONLY the active live phase wire needs to be moved! Remember the early part of this report where it is stated that the main "neutral" MUST NOT be switched, and MUST be first connected to the consumer unit earthing bar link. (this connecting to the earthing bar FIRST is part of the new Thai regulations, as in most other jurisdictions the neutral is connected to the neutral link first, which in turn is wire connected to the earthing bar. (the end result being the same!). It is also a very good safety factor.
The above now leads to a dilemma. It is very likely that you will find that your consumer unit has a double pole main breaker or MCB. To comply with the regulations this breaker SHOULD be replaced with a single pole breaker, and the incoming main neutral moved, as per the rules, to the earthing bar link, which it may or may not have! You may find that the main breaker is some form of ELCB or RCD which requires that both the active and neutral be connected to it, in which case it should be replaced.
Whatever is already installed will continue to function, with just the live conductor now coming from the transfer switch from either the mains or generator, BUT it may not be safe. The generator "neutral" will have to be connected directly to the existing neutral link bar after passing through the transfer switch.
Unless it is some form of RCD a double pole main breaker should still function safely with just one "leg" connected, but if the mains neutral is connected to the input side it will have to be moved to the neutral bar link. If it is an RCD type switch, then it will have to be replaced. RCD type safety switches should only be installed in outgoing load circuits.
The following link to Hager also has a further link to a circuit diagram as a PDF file that can downloaded and printed out:
https://www.hagerelectro.com.au/e-catal ... s/3483.htm
Depending on the age of your consumer unit it may be time to consider replacing it, if not able to modify it. They are not that expensive, and there are many options available. It would also be a good time to install an earthing system, and perhaps some safety RCD breaker circuits for such things as hot water shower heaters. If replacing an existing breaker with some form of RCD device there will probably not be enough space on your existing consumer unit.
NOTE: the new neutral rule applies to the MAIN incoming neutral, and NOT to a neutral passing through any RCD.
Transfer Switch Options
It is absolutely IMPERATIVE that whatever type of transfer switch that you install isolates the main incoming live phase supply! This is to ensure that no voltage can be "fed back" to the street supply while connected to the generator.
It also should be of the "break before make" configuration; meaning that whichever supply is being used it will fully disconnect BEFORE making a connection in the other direction.
If the switch uses contactors, then they must be both mechanically and electrically interlocked so that it is only possible for one of them to close at one time.
For this main reason I personally prefer to use a manual 3 position switch. The following is just an example of the type as it has an "off" position:
Harmony_K_K63E003WP.pdf (rs-online.com)
The Hager link above also shows a good switch.
The transfer switch must be rated at the same amps as your existing main switch and have at least 2 poles, although most of them will have 3 poles. For most houses the main switch will probably be rated at 63 amps. A big consideration will also be how you intend to mount the transfer switch. It will need to be in an enclosure of some description, and better if it can be operated without opening the enclosure.
Automatic (ATS) or Manual Transfer.
Unless you have some special needs such as being partly disabled, or need a reliable instant supply for medical equipment, I cannot see the need for an automatic transfer arrangement.
And don’t forget that even if the system starts and transfers automatically, it will still need to be stopped manually once the normal supply is restored. Just as an aside, some form of indication, such as a light or audible signal, should be installed to indicate when the mains supply is again available.
If you do decide that an automatic system is the best for you, then you will also be limited in your choice of generators to those with diesel engines. That in itself is not a bad thing, but may limit the available choice.
Although not impossible to do, a petrol engine will require at least an ignition switch. and most probably some form of choke to start it. Providing that it has a good battery, a diesel engine only needs a signal to the starter motor to start.
There are nearly as many different transfer switches as there are 7-11's in Thailand!
Some are manual only, some selectable manual or automatic, some have provision for remote transfer switching, the combination appears to be endless! As an automatic switch is more complex, it therefore follows that there are more components that can fail.
I cannot recommend any, as I have not used any of them, but point out that some of them will have magnetic coils in them as they are contactors, which may mean that in the "normal" position the coil MAY be energised and therefore a potential burn out area. You need to research each one fully and select one that suits your needs. The only REAL advice is to make sure that the amp rating is at least the same as your main switchboard breaker, as the normal load will pass through the transfer switch.
Dual-Power Automatic Transfer Switch 2P 100A Household 35mm Rail Installation | Lazada.co.th
TOMZN Single Phase Din Rail ATS Dual Power Automatic Transfer Electrical Selector Switches Uninterrupted 2P 63A 100A 125A | Lazada.co.th
ATS CSQ เอทีเอสสวิทช์ สวิตช์เปลี่ยนแหล่งจ่ายไฟฟ้าอัตโนมัติ (CSQ Automatic Transfer Switch) 63A 220V 1 phase | Lazada.co.th
Applegreen ตู้ ATS Automatic transfer switch พร้อมใช้งาน 2P 63A Single phase สวิทช์สลับแหล่งจ่ายไฟอัตโนมัติ ระบบโซล่าเซลล์ พลังงานทดแทน ไฟฟ้าสำรอง | Lazada.co.th
Changeover Switch Features (hagerelectro.com.au)
https://www.southeastthailand.co.th/contact.php (Hager agent)
If you want to go a bit bigger the following is made in Thailand, so spare parts should be available:
https://www.heretools.com/th/product/79 ... A-kwm-7500
https://www.heretools.com/th/product/78 ... wm7500-new
https://www.heretools.com/th/product/71 ... wel-8500ea
Under and over voltage protection:
On many occasions the mains supply voltage may drop substantially. Anything from the normal 220 volts down to around 180 volts or less sometimes. This condition is called a "brown out", rather than a "black out". It is mostly caused by the loss of 1 phase coming from the street transformer. The only indication that you may have is that the lights go dim, or your computer switches to a UPS or battery with a laptop. Sometimes, the smoke may escape from whatever happens to be plugged in!
Because of the way the street transformer is connected internally (star connection), there is still voltage being produced by the windings, but one phase is not carrying the correct voltage to your house. Your neighbour's house may be connected to a different one of the three phases of the street supply, and will not be affected with their lights still on.
In most cases it is a blown fuse somewhere feeding the overhead distribution wire, and not the transformer per se. If the complete transformer fails it usually goes with a big bang resulting in a complete blackout!
(this mostly happens if you live around Bangsapan
)There is now available a small device called a "voltage sensing relay". Their function is to continuously monitor the AC voltage, and disconnect at a preset point, either too low, or too high. Most can also be set to a maximum amp load.
https://www.lazada.co.th/products/volta ... ml?&search
There are a several ways that this type of device can be used. As the above example is rated at 63 amps it could be wired up to disconnect the complete consumer unit. It could be wired up just to disconnect one sensitive load circuit, such as a refrigerator or computer.
It could also be mounted in a small PVC enclosure with a plug and socket and therefore portable and used wherever sensitive equipment is plugged in.
There are many available, just search the internet.
If you have a generator with an electric starter, then a small battery will be required. The generator wil probably have a built in battery charger, but that will only work when the engine is running.
To maintain the battery a small "smart charger" should be used. They are designed to maintain a battery, especially a battery that is used on a standby starting system.
The best type is a "CTEK". but be aware that they are not cheap.
CTEK Intelligent Battery Charger XS 0.8 | Lazada.co.th
The following one is a FAKE!
Multi MXS 5.0 12V Car Battery Smart Trickle Charger & FREE INDICATOR 56-382 EU plug | Lazada.co.th
CAVEAT EMPTOR
While a standby generator is a simple circuit, it is this very fact that can, and does, lead to complacency and compromised safety.
While every care has been taken with the writing of this report, the author accepts no responsibility for the topicality, correctness, completeness or quality of the information provided.
It is very simple: if you do not know WTF you are doing, DON’T DO IT!
Or use one of these:
Hand Crank Generator Portable Device - Life Changing Products (lcpshop.net)
- hand cranked genertor.jpg (20.74 KiB) Viewed 5140 times
- sparks.jpg (49.15 KiB) Viewed 5140 times
May you be in heaven half an hour before the devil know`s you`re dead!
Re: Engineering and Technology Thread
Reminds me of much a younger Lost after a few E's at a rave. 
I don't trust children. They're here to replace us.
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pharvey
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Re: Engineering and Technology Thread
Well, this could be quite incredible - that said, when something sounds too good to be true, it normally is!! The money and capability is available to Saudi though I would say. An interesting read @https://www.bbc.co.uk/news/blogs-trending-59601335
Neom: What's The Green Truth Behind a Planned Eco-City in The Saudi Desert?
"Glow-in-the dark beaches. Billions of trees planted in a country dominated by the desert. Levitating trains. A fake moon. A car-free, carbon-free city built in a straight line over 100 miles long in the desert. These are some of the plans for Neom - a futuristic eco-city that is part of Saudi Arabia's pivot to go green. But is it all too good to be true?
Neom claims to be a "blueprint for tomorrow in which humanity progresses without compromise to the health of the planet". It's a $500bn (£366bn) project, part of Saudi Arabia's Vision 2030 plan to wean the country off oil - the industry that made it rich.
Covering a total area of over 26,500 sq-km (10,230 sq-miles) - larger than Kuwait or Israel - Neom will, developers claim, exist entirely outside the confines of the current Saudi judicial system, governed by an autonomous legal system that will be drafted up by investors."
Neom: What's The Green Truth Behind a Planned Eco-City in The Saudi Desert?
"Glow-in-the dark beaches. Billions of trees planted in a country dominated by the desert. Levitating trains. A fake moon. A car-free, carbon-free city built in a straight line over 100 miles long in the desert. These are some of the plans for Neom - a futuristic eco-city that is part of Saudi Arabia's pivot to go green. But is it all too good to be true?
Neom claims to be a "blueprint for tomorrow in which humanity progresses without compromise to the health of the planet". It's a $500bn (£366bn) project, part of Saudi Arabia's Vision 2030 plan to wean the country off oil - the industry that made it rich.
Covering a total area of over 26,500 sq-km (10,230 sq-miles) - larger than Kuwait or Israel - Neom will, developers claim, exist entirely outside the confines of the current Saudi judicial system, governed by an autonomous legal system that will be drafted up by investors."
"Hope is a good thing, maybe the best of things" - Yma o Hyd.
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pharvey
- Moderator
- Posts: 13913
- Joined: Sat Aug 29, 2009 10:21 am
- Location: Sir Fynwy - God's Country
Re: Engineering and Technology Thread
A toss-up between putting this here or in the "Amazing Nature" thread - definitely a crossover! 
The French Town Where The Lighting is Alive
From deep-sea fish to fireflies, dozens of organisms use bioluminescence to help themselves be seen in the natural world. But can we harness them to light our towns and cities?
"In a tranquil side room of the Covid-19 vaccination centre in Rambouillet, a small French town around 30 miles (50km) south-west of Paris, a soft blue light emanated from a row of cylindrical tubes. Members of the public who received a vaccine last year were invited to bathe in the glow for a few minutes while they waited in the recovery area.
Soon, the same azure glow will illuminate the nearby, tree-lined Place André Thomé et Jacqueline Thomé-Patenôtre, located just across from the aptly named La Lanterne performance hall, at night. These ethereal experiments are also underway across France, including at the capital's Roissy-Charles-de-Gaulle airport.
But unlike standard streetlamps, which often emit a harsh glare and need to be hooked up to the electricity grid, these otherworldly lights are powered by living organisms through a process known as bioluminescence.
This phenomenon – where chemical reactions inside an organism's body produce light – can be observed in many places in nature. Organisms as diverse as fireflies, fungi and fish have the ability to glow through bioluminescence. It is present in 76% of deep-sea creatures and has independently evolved dozens of times, including at least 27 occasions in marine fish alone.
The uses of bioluminescence in the natural world are just as wide-ranging. Fireflies light up to attract mates while some species of algae glow when the surrounding water is disturbed. Deepsea anglerfish allow bioluminescent bacteria to take up residence on a lobe above their head as a tantalising lure for prey.
The turquoise blue glow bathing the waiting room in Rambouillet, meanwhile, comes from a marine bacterium gathered off the coast of France called Aliivibrio fischeri. The bacteria are stored inside saltwater-filled tubes, allowing them to circulate in a kind of luminous aquarium. Since the light is generated through internal biochemical processes that are part of the organism's normal metabolism, running it requires almost no energy other than that needed to produce the food the bacteria consume. A mix of basic nutrients is added and air is pumped through the water to provide oxygen. To "turn off the lights", the air is simply cut off, halting the process by sending the bacteria into an anaerobic state where it does not produce bioluminescence.
"Our goal is to change the way in which cities use light," says Sandra Rey, founder of the French start-up Glowee, which is behind the project in Rambouillet. "We want to create an ambiance that better respects citizens, the environment and biodiversity – and to impose this new philosophy of light as a real alternative.""
Full Article and Pictures @ https://www.bbc.com/future/article/2022 ... energy-use
The French Town Where The Lighting is Alive
From deep-sea fish to fireflies, dozens of organisms use bioluminescence to help themselves be seen in the natural world. But can we harness them to light our towns and cities?
"In a tranquil side room of the Covid-19 vaccination centre in Rambouillet, a small French town around 30 miles (50km) south-west of Paris, a soft blue light emanated from a row of cylindrical tubes. Members of the public who received a vaccine last year were invited to bathe in the glow for a few minutes while they waited in the recovery area.
Soon, the same azure glow will illuminate the nearby, tree-lined Place André Thomé et Jacqueline Thomé-Patenôtre, located just across from the aptly named La Lanterne performance hall, at night. These ethereal experiments are also underway across France, including at the capital's Roissy-Charles-de-Gaulle airport.
But unlike standard streetlamps, which often emit a harsh glare and need to be hooked up to the electricity grid, these otherworldly lights are powered by living organisms through a process known as bioluminescence.
This phenomenon – where chemical reactions inside an organism's body produce light – can be observed in many places in nature. Organisms as diverse as fireflies, fungi and fish have the ability to glow through bioluminescence. It is present in 76% of deep-sea creatures and has independently evolved dozens of times, including at least 27 occasions in marine fish alone.
The uses of bioluminescence in the natural world are just as wide-ranging. Fireflies light up to attract mates while some species of algae glow when the surrounding water is disturbed. Deepsea anglerfish allow bioluminescent bacteria to take up residence on a lobe above their head as a tantalising lure for prey.
The turquoise blue glow bathing the waiting room in Rambouillet, meanwhile, comes from a marine bacterium gathered off the coast of France called Aliivibrio fischeri. The bacteria are stored inside saltwater-filled tubes, allowing them to circulate in a kind of luminous aquarium. Since the light is generated through internal biochemical processes that are part of the organism's normal metabolism, running it requires almost no energy other than that needed to produce the food the bacteria consume. A mix of basic nutrients is added and air is pumped through the water to provide oxygen. To "turn off the lights", the air is simply cut off, halting the process by sending the bacteria into an anaerobic state where it does not produce bioluminescence.
"Our goal is to change the way in which cities use light," says Sandra Rey, founder of the French start-up Glowee, which is behind the project in Rambouillet. "We want to create an ambiance that better respects citizens, the environment and biodiversity – and to impose this new philosophy of light as a real alternative.""
Full Article and Pictures @ https://www.bbc.com/future/article/2022 ... energy-use
"Hope is a good thing, maybe the best of things" - Yma o Hyd.
Re: Engineering and Technology Thread
^^^ Very cool! If they can manage to harness the power of those things efficiently, they're on to a winner!
Saw this which I thought was pretty neat. 18th Century French safe. No way I'm remembering the sequence to this and there's no 'forgot my password' option.
Nice design, though. Those keys! Don't make 'em like they used to.
Saw this which I thought was pretty neat. 18th Century French safe. No way I'm remembering the sequence to this and there's no 'forgot my password' option.
Nice design, though. Those keys! Don't make 'em like they used to.
I don't trust children. They're here to replace us.
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pharvey
- Moderator
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- Joined: Sat Aug 29, 2009 10:21 am
- Location: Sir Fynwy - God's Country
Re: Engineering and Technology Thread
^ Pretty sure if I had one of these, anything that was put in would still be there!!
"Hope is a good thing, maybe the best of things" - Yma o Hyd.
Re: Engineering and Technology Thread
I had a casio once.
I don't trust children. They're here to replace us.
Re: Engineering and Technology Thread
Pretty cool.
I don't trust children. They're here to replace us.
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lindosfan1
- Deceased
- Posts: 4069
- Joined: Wed Mar 05, 2008 1:26 pm
- Location: uk
Re: Engineering and Technology Thread
Turning nuclear waste in to batteries that would last for thousands of years.
Woke up this morning breathing that's a good start to the day.
Re: Engineering and Technology Thread
I don't trust children. They're here to replace us.
Re: Engineering and Technology Thread
They really are clever and so graceful when they walk.
There's some great video of how they've evolved over the last 25 years or so. The first one was impressive but then went in leaps and bounds to what they are today.
Incidentally, you can buy working mini models online.
There's some great video of how they've evolved over the last 25 years or so. The first one was impressive but then went in leaps and bounds to what they are today.
Incidentally, you can buy working mini models online.