Generator / Transfer switch guidance please


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Old 03-10-10, 04:25 PM
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Generator / Transfer switch guidance please

So I have a small generator, running watts of 2,200 and peak of 2,800 with a 15 amp breaker - the catch is it does NOT have a 240 plug, only 2 120 plugs... When I look around for 120v transfer switches they are all rated for a max generator of 1,800 or 1,875. All I want to run is my furnace (which at peak I believe will draw 1,400) and a few lights. I found a Generac with 6 breakers on it, but again --- says for a maximum of 1,875 running watts.

Does my larger generator only output the number of watts required by what it is running (for example I assume it doesn't output 2,200 watts if running a 40 watt lightbulb)?

Can I use a switch like this for my generator without having a fire risk? I've read over powering a transfer switch can lead to burning out nuetral wires and creating fire risk...

Any general guidance would be much appreciated...
 
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Old 03-10-10, 06:13 PM
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Originally Posted by Derekrobi
So I have a small generator, running watts of 2,200 and peak of 2,800 with a 15 amp breaker - the catch is it does NOT have a 240 plug, only 2 120 plugs... When I look around for 120v transfer switches they are all rated for a max generator of 1,800 or 1,875. All I want to run is my furnace (which at peak I believe will draw 1,400) and a few lights. I found a Generac with 6 breakers on it, but again --- says for a maximum of 1,875 running watts.

Does my larger generator only output the number of watts required by what it is running (for example I assume it doesn't output 2,200 watts if running a 40 watt lightbulb)?

Can I use a switch like this for my generator without having a fire risk? I've read over powering a transfer switch can lead to burning out nuetral wires and creating fire risk...

Any general guidance would be much appreciated...
I dont have much expierence with smaller gen systems. But i would think that the generator is only going to put out what is being used. You are correct to assume that if a 40 watt bulb was hooked up to it, its not outputing 2000 watts. As longs as you dont connect more than the transfer switch is rated for you should be ok.
 
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Old 03-10-10, 06:37 PM
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Have you looked at furnace transfer switches since mainly it is the furnace you are interested. Just Google. You could maybe run a small subpanel off one. 120v sub panels aren't common but 240v sub panels are cheap and can easily be converted to 120v. You could perhaps change over one light circuit and the furnace to the small subpanel.
 
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Old 03-10-10, 08:56 PM
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our just put the small furnace transfer switch on the furnace and then run a extension corn to it and other extension cord to the freezer and a lamp ect.... this would cost you alot less and be nice and simple
 
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Old 03-11-10, 06:22 AM
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I've found a reliance furnace transfer switch, but still rated at 1800 watts (120vX15amps=1800 watts, I assume this is a correct calculation) --- for only $10 more dollars ($119) I can get a transfer switch with 6 breakers on it... I figured I'd just wire the fridge etc instead of running cords through the house with an infant running around.

The root of the issue is not having a 240v output on the generator, but I got a steal of a deal on it, I bought it when I was on public water, now that I have a well pump I dont feel like selling it and paying way more for a bigger generator... I just want to keep the house warm, I can deal without running water for a bit, I have a river behind my house I can use to flush toilets and I can go to the in-laws to shower. Just dont want the pipes to freeze or loose $100's in groceries...

I assumed if I bought the 120v transfer switch and only ran the furnace (which hardly runs because the house is brand new and very tight) and the fridge and a few lights I should be good as long as I dont draw more than 1800 watts through it.

here is the one I want: A.P. Electric & Generators - Generator Related Super Store.

Thanks for all the replies -- I want to feel a little more knowledgable before I buy it and try to do it myself or hire a buddy who is an electrician (I don't want to sound too inexperienced!)
 
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Old 03-11-10, 08:36 AM
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Nothing wrong with that switch at all. GenTran makes among the best. They are extremely easy to install too. Basically that flexible conduit coming out of the bottom has 2 wires for each transfer switch (in and out), plus a neutral and ground. You connect the neutral and ground to their appropriate bus bars, then select the breakers you want to have on backup. Loosen the screw on each selected breaker and remove the wire. Insert the IN wire from one switch and fasten to the breaker. The wire you just removed from the breaker gets connected to the OUT wire from that switch. Repeat for the remaining switches (you don't have to use them all). Easy enough?

You just have to be careful what you are connecting because you only have the 15A to work with. Look at the nameplate on the furnace and see what its operating power is, since that would be the biggest load. Subtract that to find out how much power you have left.

Since you sound unsure of yourself, make sure you turn the MAIN breaker off before you start working. Better yet, if there is a main breaker at the meter, turn THAT off, because it will kill all incoming power to the breaker box. If there isn't, just be aware that even with the main in the breaker box off, there will still be 240V @ 200A at the very top terminals. Stay away from there!
 
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Old 03-11-10, 09:29 AM
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Thats more reassuring -- I've watched videos of how to install, that doesn't worry me too much... I've done some light electrical work and the first time I shock myself or spark something, I stop and call an electrician I know who is cheap haha.

My furnace I believe I read will draw about 12 amps and it has a 1/3 HP fan I think so thats about 1400 watts. The switch has meters on it, so I'll know what I'm putting through the switch. My main concern is putting a generator with HIGHER running watts than the switch recommends. But it sounds okay...

Any other thoughts that I need to have before doing this all? Am I missing anything? I assume as long as the fridge and furnace dont turn on at the same time I should be okay - and if they did it would just throw the breaker, right?
 
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Old 03-11-10, 12:22 PM
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You shouldn't need to be worried about the higher rating on the generator. That just means it is CAPABLE of PROVIDING more than the 1850w, not that it will FORCE more power. The only reason for concern is if the generator has 20A outlets (they have a "T" shaped slot for one of the prongs). If so, there is a good possibility that the main breaker is rated for more than 15A (generator breakers sometimes have odd ratings, like 12 or 18A instead of the multiples of 5 and 10 like we're used to). Check that to be sure, and also make sure you use a heavy duty (contractor or generator grade) extension cord with at least 12GA conductors, preferably 10GA. Your standard orange backyard extension cord is wired with 16GA and will overheat with a fully loaded transfer switch, especially if it is long.
 
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Old 03-11-10, 01:14 PM
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Originally Posted by JerseyMatt
You shouldn't need to be worried about the higher rating on the generator. That just means it is CAPABLE of PROVIDING more than the 1850w, not that it will FORCE more power. The only reason for concern is if the generator has 20A outlets (they have a "T" shaped slot for one of the prongs). If so, there is a good possibility that the main breaker is rated for more than 15A (generator breakers sometimes have odd ratings, like 12 or 18A instead of the multiples of 5 and 10 like we're used to). Check that to be sure, and also make sure you use a heavy duty (contractor or generator grade) extension cord with at least 12GA conductors, preferably 10GA. Your standard orange backyard extension cord is wired with 16GA and will overheat with a fully loaded transfer switch, especially if it is long.

The generator has a 15amp breaker on it as well - so I assume no issue there... I didn't put much thought into the extension cord.. Now that I'm comfortable, I'll order the switch and locate a 12 or 10 gauge cord so it won't overheat anything. Thanks for the GREAT info Matt.
 
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Old 03-11-10, 02:00 PM
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If its over 50 feet i would go with 10..under 50 feet a good quality 12 would work

only thing is some 10 gauge cords have 20 amp plug on them that wont plug into a 15 amp plug watch out for this..if your generator has a 20 amp T slot plug then no issues there
 
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Old 03-12-10, 05:54 AM
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Originally Posted by braether3
If its over 50 feet i would go with 10..under 50 feet a good quality 12 would work

only thing is some 10 gauge cords have 20 amp plug on them that wont plug into a 15 amp plug watch out for this..if your generator has a 20 amp T slot plug then no issues there
Ill keep it under 50 feet so I can stick with a regular 15 amp plug -- just ordered the switch online based on the info I gathered here -- I'll probably mount it and attempt to hook it up and if I get confused (although it looks straight forward), its worth hiring someone so I don't burn down my 6 month old house
 
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Old 03-16-10, 02:21 PM
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Originally Posted by JerseyMatt
Nothing wrong with that switch at all. GenTran makes among the best. They are extremely easy to install too. Basically that flexible conduit coming out of the bottom has 2 wires for each transfer switch (in and out), plus a neutral and ground. You connect the neutral and ground to their appropriate bus bars, then select the breakers you want to have on backup. Loosen the screw on each selected breaker and remove the wire. Insert the IN wire from one switch and fasten to the breaker. The wire you just removed from the breaker gets connected to the OUT wire from that switch. Repeat for the remaining switches (you don't have to use them all). Easy enough?

You just have to be careful what you are connecting because you only have the 15A to work with. Look at the nameplate on the furnace and see what its operating power is, since that would be the biggest load. Subtract that to find out how much power you have left.

Since you sound unsure of yourself, make sure you turn the MAIN breaker off before you start working. Better yet, if there is a main breaker at the meter, turn THAT off, because it will kill all incoming power to the breaker box. If there isn't, just be aware that even with the main in the breaker box off, there will still be 240V @ 200A at the very top terminals. Stay away from there!
Anybody have any thoughts about me installing a breaker between the generator and the switch (given my situation), necessary, waste of time and money? Any input would be appreciated
 
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Old 03-16-10, 03:52 PM
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Originally Posted by Derekrobi
Anybody have any thoughts about me installing a breaker between the generator and the switch (given my situation), necessary, waste of time and money? Any input would be appreciated
Dont think thats needed, there should be Over current protection built into the generator.
 
 

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