transfer switch - wire gauge

soma

We're installing a transfer switch (general electric TC10323R) Transfer Switch-TC10323R for a 7000W generator. The specs for the switch say it can accommodate "12 - 1 AWG/kcmil". Does that mean it's supposed to fit from #12 gauge to #1 gauge? The specs also say "Single-phase, 3-wire SN, 100 Amp , 120/240 VAC". That would seem to imply that each lug could take up to 100A (#1 gauge) wires. However, our #2 gauge wires were too big for it and it seems only #4 gauge could fit.

Our breaker box has 2 #2 gauge wires going into the main breaker. The main breaker has 2 breakers tied together and says "150A" on it. I assume this means that each half can take 75A?

We were thinking of using a split bolt connector to splice the #2 gauge from the meter down to a #4 gauge to the transfer switch. Then running the #4 gauge back to the main breaker.

Wondering what the codes might be for this and also if there would be any problems from the insurance companies.

Thanks.

AllanJ

Each half can take 150 amps. This means that, for each side, the 240 volt load altogether plus the total 120 volt load on that side can add up to 150 amps.

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kennzz05

generator can only produce 7000 watts thats only about 30 amps so unless the wire is making an extremely long run from switch to panel size the wire for 40 amps and id think youd be good to go. its not like youre gonna be able to run the whole house on it

that switch is way way overkill
if it isnt an automatic switchover you could do the same thing with a 40 or 60 amp disconnect box, which you could also fuse for added protection looking at the chart i found online it says #4 wire for copper conductoI am NOT an electrician but have almost 30 years in the hvac field and have never seen #4 used on any piece of residential a/c equipment or electric heating equipment that is rated at 30 amps. but you can take that with a grain of salt I would think #8 would be fine but again im not an electrician

id be more concerned about carbon monoxide fumes killing you from poor generator placment than using #8

soma

The problem is that the wires from the meter are #2 (or #1) gauge, so when the switch is in the meter position it's going to be running the whole house and the code may say it needs to be the same as from the meter.

zappa

You are correct. You would need a transfer switch that is rated for your 150 amp service.

kennzz05

As you may have guessed I obviously have no experiance with transfer switches, and had no clue that the entire load of the house ran thru them when not being used. Oh well I have done the same with a disconnect box for about 30 dollars so I just assumed the transfer switches were similar. Sorry, carry on.

frenchelectrican

#2 AWG will fit in the lug no question asked the #2 is smaller than #1 is. However there is other issue allready arise so read the below comment you will see why.
The first number I did see you say 150 amp which you have 150 amp service however the first red flag it threw across my face as you mention conductor size above which it is #2 AWG but is that in copper or Alum ? Either way the transfer switch(which you posted above) is too small for 150 amp service. The #2 copper / Alum is typically used on 100 amp service.

Don't go there it is not legit to do that due the #4 is only good for 80/75 amp Cu/AL and with good load on it can cause the #4 conductor overheat before the 150 amp breaker will ever trip.


Get proper permits for this and really between the main breaker and whole house manual transfer switch.,, better off have electrician to do this due some of the local codes will not allow the homeowners to hook up the transfer switch in this manner between the meter and main panel.

What brand name main breaker panel you have I know some brand you can able add a interlock and two pole breaker for it only if you have room in the panel { so please post the model number then we can able assit you the correct one }

The other thing is that many POCO will be happy to disconnect it for you but will not hook it up until it is inspected by electrical inspector or inspector from your area and JAMAIS ( NEVER ) remove the meter while the load still on the upper lugs are alive all the time and it is unfused so if that shorted out for some reason it will run like runaway welder until the conductor burn out or POCO transfomer fuse blow out. ( one of the two )

Merci,
Marc

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soma

I already put in a meter panel and mast and ran the wires to the mast on a house where a tree had fallen and knocked the wires down along with the roof and mast. Had the inspector come and then the poco turned on the power.

It's a crouse-hinds e26095, but an employee at home depot told us that a friend of his recently had a fire and the insurance company refused to cover because he had an interlock on his breaker panel (with the back feed breakers).

The current might arc between the upper and lower connectors?

Another thought was to put in a 100 amp double breaker instead of the 150. Haven't tried to figure how much the extra 50 would be needed yet.

I have to take another look at the wires and measure them to make sure the size and material. The gauge size didn't seem to be visible from the markings on the the romex. (A contractor friend of ours said the wires were #2 gauge just from the size of the wire).

Thanks.

zappa

It sounds like your main problem is the incoming service wires are too big to fit into the 100 amp transfer switch so I don't see how downsizing the breaker would fix that problem. It's very simple, if you have a 150 amp service get a 150 amp transfer switch.

Are you sure on the gauge? Could they be 1/0 or 2/0? Are they copper or aluminum? Where are you getting your wire size information from? The reason I'm asking is the 100 amp switch you listed says it will accept #1 so I'm sure it will unless there is some sort of typo on the specs.

I can't imagine an insurance company doing such a thing because of an interlock, they are foolproof. If that is the case they could deny a claim with a transfer switch as well.

soma

The confusion was caused because the person at home depot said that the wire we bought was #3 gauge when it was 3/0 (000). We ended up getting a 200A version of the transfer switch (GE 10324R) which is able to take up to about 5/0 gauge wire.

Thanks for the replies.

soma

Incidentally, it seems like the interlock switches are against code in ny but transfer switches are ok.

Speedy Petey

Where'd you hear this???

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soma

A friend of mine saw an article online that said that ny state recently changed the laws making it a requirement to have a transfer switch for a generator so that people can't hook them up directly to the breakers. Since it only mentions transfer switches and not interlocks, she thought that might be why the insurance company wouldn't cover for an interlock.

I'll try and find the article and get back.

Speedy Petey

I have not head one thing about this. I don't think she is reading it right.
There is no "new" law requiring transfer switches. It has always been illegal to hook directly to breakers without some form of transfer or interlock.

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Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.

Speedy Petey

I think the guy at HD was wrong, as usual.

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Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.