Genset For The Rainy Season Fy Dops

[Crossy]

A few pointers muratremix

You do tend to get what you pay for when it comes to small generators, the really cheap baby ones tend to have 2-stroke engines which are thirsty to run, they're fine for occasional use but I would avoid.

Be careful when sizing, don't run your unit over 60-70% load (they're most efficient then anyway), and both myself and steve have had issues with gensets which failed on marginal overloads.

I have a Kwai Thong EP6500ES rated at 5500VA http://www.kwaithong.com/product100.html , it's been reliable over the flooding season but we don't load it over about 3500 Watts. I've installed an additional 15A breaker just in case someone tries to use a big appliance, but it happily runs the fridge/freezer, microwave and water pump along with the TV and some low energy lights. It cost us 23,000 Baht from our local farmers outlet.

I've also done a DIY conversion to LPG which should be cheaper to run than gasoline, proper testing once we get moved in to the house from our current condo.

As I've noted earlier in this thread, it is vital that any transfer mechanism you use makes it impossible to connect the genset and incoming mains at the same time.

[bankruatsteve]

Just to follow up a bit with my Kwai Thong 2000W genset.... it's a longer story but to be brief: The unit would work great supplying 6.5 max and 1.2 nominal (that's running vs startup which if everything started same time probably well over the 9 amp). BUT - after 15 minutes the alternator shuts down and I'm "pretty sure" it's some kind of thermal trip. Why not just use the overload protection is beyond me but it must be something thermal related b/c the alternator kicks out after a few seconds if try to re-start before a complete cool down.

So, I'm in the process of returning it to Bangkok for "fix" - did that once before but this time I'm including my description of the problem as the dealer simply sent it back the first time with nothing. And the replacement unit did exactly the same. I'm thinking this could be a production issue that I'm just unlucky to get two of the same problem. Otherwise, I would be very happy with it.

[bankruatsteve]

Use a 10amp 3 core extension lead with a couple of power boards with over current protection with 3 pin plug top and socket outlets. You then do not have to install anything, Plug the extension lead into the 3 pin outlet on your generator. You will only have to use it if the power is lost for a considerable period.

And it is far safer for all concerned.

That would be if the genset has a 3-prong outlet. Mine doesn't. The electrics are grounded to the chassis - but that's it. But, I don't view that as any issue if it's connected to my house circuits.

[electau]

Safety.

NEVER use a lead to connect a generator with a plug top on each end an insert in a socket outlet to supply power.

This is known as backfeeding and is hazardous as it will feed supply back into the electricity network.

Use an inlet socket and changeover switch, with the lead having an extension socket at one end and a plug top on the other.

[billd766]

I vaguely remember many years ago a switch that I can only describe as an inverted Y switch.

The output was taken from the top of the inverted leg and an input from the mains and from the genset were connected to each leg.

It was only possible to physically connect one supply at any time as the output would only connect with either input but not both.

Each power supply would be isolated from the other so you would not be feeding the Thai national grid.

It was a covered unit so it was not really possible to stick your fingers inside to see if it works.

Using something like that witha low wattage bulb connected to the mains side and in a visible position in the house means that the bulb would be out when the genset was connected and lit when the mains is on.

So on genset only you would have a visible indicator for when the mains come back.

I have a better visual indicator as I can see the street lamps from the house.

I have attached a simple drawing of something like it.

Y switch.xls

[Crossy]

It's called a Transfer Switch and it's the beast we're always talking about whenever generators are discussed.

Have a look here

[bankruatsteve]

It's also called a DPDT switch (which has several variations). Great if you can find it. There are alternative methods which are also safe.

[bankruatsteve]

Final Chapter: After taking my Kwai Thong 2000W genset back the 2nd time, the dealer gave me a "new" one. I'm pretty sure that was the one on display so maybe the old new one. In any case, I now have survived 6 hours of power out with the "new one" and everything is good. The genset burps a little when the water pump is used but happily continues to provide. While I wasn't vigilant, I did measure some of the time and find that it was pumping a bit over 6amps when the water pump was on to a nominal of about 1.5amps. That's with 2 refrigerator, 1 water cooler, and various lights and fans running and a TV. So, that's what I was hoping to get and now I'm happy. And... while I would have preferred the DPDT switch, it's a no brainer to open one DPST switch and close another - and nobody gets killed. Cheers.

[Daffy D]

Daft question but I gotta ask

Your house is running off the generator, how do you know when the mains electricity comes back on?

[Tywais]

Daft question but I gotta ask

Your house is running off the generator, how do you know when the mains electricity comes back on?

Look at the other houses around you? Ok, just kidding. Easiest is to have a light bulb or other indicator on the incoming line to the transfer switch.

[Daffy D]

Daft question but I gotta ask

Your house is running off the generator, how do you know when the mains electricity comes back on?

Look at the other houses around you? Ok, just kidding. Easiest is to have a light bulb or other indicator on the incoming line to the transfer switch.

Right, that's what I figured.

But reading trough the posts seems the idea is to have at least the TV and fridge and AC running off the genny, so you're relaxed in your cool room in front of the telly with a cold beer waiting for the mains to come back on.

Do you have an indicator light positioned over the TV to show when the mains come back on or do you have to get up and go to check the transfer switch at regular intervals?

Obviously every one has their method just wondering what it is.

[bankruatsteve]

Yeah, I was thinking about putting in a little indicator light but around here the initial power return tends to be at wierd voltage - usually low (50v) but sometimes quite high (280v). So, when I hear the village rumble of "FY LAOW" I go up and check voltage before shutting down the genset.

[genset]

For anybody considering this type of installation, I've posted some photographs of the simplest and safest type of open transition (break before make) rotary transfer switch for these applications. They can be found in this thread.

Genset

It's also called a DPDT switch (which has several variations). Great if you can find it. There are alternative methods which are also safe.