Electricity Generator (petrol/diesel)

[gouda]

I'm thinking of getting a petrol or diesel generator to supply electricity when the main supply drops

can anyone tell me how to hook it up to the house circuit?

petrol or diesel ?

expect to run the following at most

lights

fridge freezer

PC

TV

microwave possibly

3 x 13,000BTU air cons (or possibly fans if can't afford a large enough generator )

most local shops sell chinese made ones , 15Litres fuel tank, 2 or 3kw about 9000Bht, although saw a Kawasaki 2Kw at 20,000Bht... is it worth the extra cash for a Japanese made one?

TIA

[Forkinhades]

red to red

black to black

blue to <deleted>

[Forkinhades]

sorry could'nt resist.

Anyhow its not straightforward, you will need to get a good engineer. As you will need changeovers switches, contolled by contactors for when the power drops, and for when the power comes back on. Or you will have serious problems

[Forkinhades]

Also you will have to consider what circuits that you wanted to run off the generator, as 3kw aint going to do much. Would probably mean a second Fuseboard with dedicated circuits for the power cut.

[trogers]

Three kilowatt cannot even power my shower heater which is rated at 3.8KW. Sounds like a generator used by hawkers for night lighting.

[Artisi]

3kW - you will be able to run some lighting and your fridge/freezer, TV and possibly a fan or 2.

For automatic change over to your genset on a power failure and back again on reinstatement of power will need a fairly complex purpose designed switching arangement connected only to dedicated circuits - a manual system of a few extension leads to your fridge/freezer and some temp. lighting probably easier amd less problematic.

[TexasRanger]

You could just go for the manual change over which I plan to have installed soon. Just a manual change over switch to swap between genny power and grid power going into the consumer unit and then you can just open the breakers you don't want to supply power to. I will probably not power my A/C units as they will require a much bigger generator and the power outages are not that frequent. I have been looking at a 5.5Kw which should be OK for running my fridge and water pumps and some lights.

[sorensen]

For a genset you need reliability, so go for the Japanese quality model and make sure you size it right. A petrol model is best for the small size and diesel for the bigger 100+ KW.

Make sure you know how to service the unit and have spare engine oil. Unlike a car, you very quickly run it for a lot of hours. Normal oil change is every 250 hours or just 10 running days.

I would also set it up with manual connection, so have a flashlight handy.

[Crossy]

OK, a transfer switch is what you want, a manual one will do the job if you don't want auto start.

It is vital that the genset and the mains cannot be connected to the load at the same time so a simple arrangement of breakers will NOT do, you need a proper transfer switch. The pukka device will have two or maybe three positions Mains==Off (maybe)==Genset. A simple diagram here (ignore the weird colours) http://www.electrical-online.com/generatortransferswitch.htm

It's easy enough to wire up, your biggest issue will be that the genny won't run your entire load, so no kettles, microwaves etc or it will splutter to a halt

Make sure that your man uses adequately sized cables and that the Genset input is protected by its own breaker.

If you need auto switchover and autostart of the genset things will get more complex particularly if your genset can't handle the whole load.

I really must knock up a decent diagram as more and more people are asking how to do this.

Whatever you do, do NOT, that's NOT use the typical Thai technique involving a lead with a plug on each end!!

Any problems, please ask.

[Gary A]

Unless you are willing to buy a HUGE genset, you would be better off to install a manual switch then turn off the breakers for the aircon and water heater. A 10 HP kubota diesel will give you about 6,000 to 7,000 watts.

[Daffy D]

Whatever you do, do NOT, that's NOT use the typical Thai technique involving a lead with a plug on each end!!

[newtronbom]

I have just been through this with my yacht. You can get a diesel generator near "Khlong Thom Center", 6000 watt (6 KWT), 220 vlt, that has a plug in board for an extension type cord, or a direct connection for wiring, that is electric key start and comes with a battery and a one year guaranty, for about 38,000 Thai baht. The same genny sells in other shops for over 65,000 baht! You need to work out what the power demand in your house is, in watts, before you buy anything. The lower the wattage, the lower the price. You need to add up things like air con, refridgerator, TV, etc. It May pay you to get a sparky to do the math for you if you are not sure. There are also gadgets, that will auto start the genny if the power goes out. The one I am buying, can also be used as an arc welder! It is very quiet and very fuel efficient and comes in a nice looking frame. hope this is of some help to you. Please "PM" me or email me, if you need more help. Mitch Newton.

PS: here is a link to give you an idea of what it looks like and a price >> http://www.emergencypower.com/Portable-Die...-AGI6800DE.html <<

[Artisi]

I have just been through this with my yacht. You can get a diesel generator near "Khlong Thom Center", 6000 watt (6 KWT), 220 vlt, that has a plug in board for an extension type cord, or a direct connection for wiring, that is electric key start and comes with a battery and a one year guaranty, for about 38,000 Thai baht. The same genny sells in other shops for over 65,000 baht! You need to work out what the power demand in your house is, in watts, before you buy anything. The lower the wattage, the lower the price. You need to add up things like air con, refridgerator, TV, etc. It May pay you to get a sparky to do the math for you if you are not sure. There are also gadgets, that will auto start the genny if the power goes out. The one I am buying, can also be used as an arc welder! It is very quiet and very fuel efficient and comes in a nice looking frame. hope this is of some help to you. Please "PM" me or email me, if you need more help. Mitch Newton.

PS: here is a link to give you an idea of what it looks like and a price >> http://www.emergencypower.com/Portable-Die...-AGI6800DE.html <<

If buying one, make sure it's 50 Hz as the spec. sheet lists it as 60.

[newtronbom]

I have just been through this with my yacht. You can get a diesel generator near "Khlong Thom Center", 6000 watt (6 KWT), 220 vlt, that has a plug in board for an extension type cord, or a direct connection for wiring, that is electric key start and comes with a battery and a one year guaranty, for about 38,000 Thai baht. The same genny sells in other shops for over 65,000 baht! You need to work out what the power demand in your house is, in watts, before you buy anything. The lower the wattage, the lower the price. You need to add up things like air con, refridgerator, TV, etc. It May pay you to get a sparky to do the math for you if you are not sure. There are also gadgets, that will auto start the genny if the power goes out. The one I am buying, can also be used as an arc welder! It is very quiet and very fuel efficient and comes in a nice looking frame. hope this is of some help to you. Please "PM" me or email me, if you need more help. Mitch Newton.

PS: here is a link to give you an idea of what it looks like and a price >> http://www.emergencypower.com/Portable-Die...-AGI6800DE.html <<

If buying one, make sure it's 50 Hz as the spec. sheet lists it as 60.

Cheers for that, though I was only showing that link as an example of what it looked like. Good comment though.

[gouda]

thanks guys, good info

i was thinking of a manual changeover.. the transfer switch seems perfect...

the ones i saw have their own breakers on the front panel if i remember correctly

will most prob have to open the piggy bank to get a larger 6 or 7KW one

may have some more questions when i get all the parts... cheers

[genset]

I'm thinking of getting a petrol or diesel generator to supply electricity when the main supply drops

can anyone tell me how to hook it up to the house circuit?

petrol or diesel ?

expect to run the following at most

lights

fridge freezer

PC

TV

microwave possibly

3 x 13,000BTU air cons (or possibly fans if can't afford a large enough generator )

most local shops sell chinese made ones , 15Litres fuel tank, 2 or 3kw about 9000Bht, although saw a Kawasaki 2Kw at 20,000Bht... is it worth the extra cash for a Japanese made one?

TIA

Hi Gouda,

As Crossy suggested, a three position transfer switch is the best method of connecting the supply from a small generator to your distribution unit. I have attached a picture showing the relationship between the generator supply, mains supply, the transfer switch and your distribution unit, just so you are clear on how this all fits together. Small or large generator, manual or automatic transfer switch, the relationship between the individual parts remains the same.

The first position on the transfer switch makes the connection between your mains supply and the distribution board, this is the default position when you have a healthy mains supply. As the transfer switch moves to the second position, it breaks the connection between mains and board and ensures that the mains supply and generator supply CANNOT be connected simultaneously to the load. The third position makes the connection between the generator supply and the distribution board.

If practicable, Forkinhades suggestion of a dedicated fuseboard for the circuits you wish to run from the generator supply is a good idea. It is common to place emergency lighting circuits for example together in one sub panel so you dont have to turn other circuits on and off when you transfer from mains to generator power if you are using a small generator insufficient to power all your appliances.

For small generators such as those you appear to be considering (2 to 10kw range), I would recommend a manual transfer switch every time. Please don't try to cobble together an automatic switch if you are not familiar with the principle of its operation. It requires two contactors connected with a manual interlock to be energized/de-energized when specific parameters are met and is not the kind of thing you should be attempting without some knowledge of how these systems work (no disrespect intended), always defer to a knowledgable spark if you are in doubt... I do.

One other point on the small petrol gensets, they run at 3000rpm, they run hot and they are relatively noisy. Although you may save some money short term, they will have a limited lifespan. If you are looking for something to stand the test of time and can afford to wait and save a bit more cash, and having looked at your wish list of appliances to run, a small diesel generator in the 15- 20kW range would be my suggestion.

Good luck with your project...

Cheers,

Genset John.

[genset]

sorry could'nt resist.

Anyhow its not straightforward, you will need to get a good engineer. As you will need changeovers switches, contolled by contactors for when the power drops, and for when the power comes back on. Or you will have serious problems

A picture of the contactor arrangement in an Automatic Transfer Switch panel for single phase application can be seen at the bottom of this page http://www.generatorsolutions.org/#/automa...itch/4534214910 the notations show the connection points for mains supply/generator supply and the connection point out to the distribution board (into the bottom of each contactor and out from the top of the mains contactor on the left side of the picture), but these cables are not fitted. The oblong grey box sandwiched between the contactors is a mechanical interlock. When one contactor is energized the interlock prevents the other contactor from closing.

Genset John.

[elkangorito]

Contactors are all well & good provided that the prospective fault current is low (<5kA). A "solid state" ATS logic controller in a country like Thailand is asking for trouble unless the logic controller is protected against all manner of "dirty electricity".

Sorry. I couldn't resist (after having an 8 month sabbatical).

[sorensen]

Some good info here:

http://www.generatorjoe.net/html/FAQ.html

Edited July 17, 2009 by sorensen

[Crossy]

Contactors are all well & good provided that the prospective fault current is low (<5kA). A "solid state" ATS logic controller in a country like Thailand is asking for trouble unless the logic controller is protected against all manner of "dirty electricity".

Sorry. I couldn't resist (after having an 8 month sabbatical).

Welcome back mate, you've been missed

[tjo o tjim]

A "solid state" ATS logic controller in a country like Thailand is asking for trouble unless the logic controller is protected against all manner of "dirty electricity".

What is the complaint with solid state controllers-- failure due to bad supply, excessive transfers, or failure to transfer when needed? Compared to using an under-voltage relay, I would rather have a microprocessor driven system any day, where I can set specific tolerances for different conditions.

[elkangorito]

When a microprocessor controller fails, the whole lot fails, which is the same as a "relay" based logic controller. The only difference is that most of the time, a relay is cheaper to replace than a complete microprocessor control unit. Also, a relay failure is "diagnosable".

About the contactors, they are used to switch loads & not act as circuit breakers. There is a big difference.

Thanks Crossy I'm decidedly a little more subdued these days so I'm sure others will find me "easier to handle".

Edited July 20, 2009 by elkangorito