Hooking up a home generator

[lakelandcat]

Need more tech help than is cramed in my brain. I want to hook up my 7.5 hp homesite 4300W gen. to the main house. What I would like to do is hook it up in my shop and when I lose power run the main house. I understand that a transfer switch will transfer power from the main transformer to my portable gen. Here is my problem, my shop is after the meter, but before the main panel box. Do I have to run 2 transfer switches? It's not a big gen. but enough for emergency applications. Can it be done? I want to make it a permeant application. My panel in the shop is 200A, fed with 4.0 thhn, Neutral is bonded to ground, per inspector. Any help is appreciated. Mike

 

[m32825]

If you kill the main breaker in the shop does the house stay on or go off?

If it stays on you will have to pull the meter to power the house.

-- Carl

 

[theoldwizard1]

There is no SAFE/APROVED way to do what you are asking WITHOUT PULLING MORE WIRE !

 

[KRB52]

Somehow, you have to interrupt the connection between the incoming line and the house. You said the power comes to the shed then to the house. Is there a main breaker in the shed? If so, that will have to be turned to "OFF" before running the generator.

 

[finn]

You have to trench and run a new wire to the house and install a generator panel or transfer switch on the main panel.

I just went through this and ended up storing the generator in the shed rather than the garage, since the shed is closer and less trenching is required. ( actually, I put an outlet on the side of the house, since there was 3’ of snow on the ground at the time, and am using an extension cord to the generator until I get around to doing the trenching)

 

[PCustoms]

You have POCO-->Meter-->Garage-->House (house is fed from garage panel), correct??

You need an interlock kit at the garage that locks out the main breaker and turns on the generator breaker, which will be backfed. I believe you also need a tiedown kit for the backfed breaker.


If you have:
POCO-->Meter THEN
--> Separate line to Garage
--> Separate line to house (fed from Meter's dual lugs, NOT garage panel)

Then you need to get a transfer switch, and I believe by code you have to size the generator for the entire possible load of the house and garage.

 

[theoldwizard1]

Here is my problem, my shop is after the meter, but before the main panel box (in the house ?)

The following statement is just plain WRONG !

There is no SAFE/APROVED way to do what you are asking WITHOUT PULLING MORE WIRE !

So the house is actually wired as a "sub-panel" to the shop, correct ?. The simplest solution is to install a generator interlock kit in the shop. When the generator is running and the interlock is flipped (it is actually a type of transfer switch) everything in your shop and hose will have power. Use it wisely.

 

[theoldwizard1]

Then you need to get a transfer switch, and I believe by code you have to size the generator for the entire possible load of the house and garage.

Only if it is a "permanent" generator with an automatic transfer switch.

4,300 watts can run a lot of things !

 

[yeldogt]

Think you better explain a bit more. Where the feed as it leaves the meter goes --- you obviously have a sub-panel?

 

[txvwnut]

This is how I have mine setup. It stays in the shop which has a sub panel fed from the house. I have a breaker in the shop panel that is just for the generator. When I loose power I just shut off the main breaker in the house panel and plug in the generator and back feed everything from there. Is this setup code legal, no it’s not but it’s how I do it.

The thing with transfer switches for small generators is they are only for a couple of circuits and not whole house setup so you’ll need to put the transfer switch on the house panel and wire to it which circuits you want to backup.

The OP’s 4300w generator is going to be really light for a whole house backup. I run a 6500w with 8500w surge capabilities and it’s right at its max power factor running my house.

 

[lakelandcat]

If you kill the main breaker in the shop does the house stay on or go off?

If it stays on you will have to pull the meter to power the house.

-- Carl

House stays on, just like normal. Shop is not tied to house in series. Coming out of the meter shop goes one way and house another. If I trip main in shop I wouldn't have circuit to power. My thought is if I put transfer switch between gen. and shop panel it would give me pwr. to shop, if I tied to main in shop it would take me back to meter, if I used another transfer switch before main house and shop would it pwr. house? I don't want pwr. to run my meter backwards. With that in mind, how does a transfer switch work, manual or auto? No need to run new wire I have 3/ 4g copper thhn buried already. 2 hot and 1 neutral. Shop is grounded with 2 rods. Plenty safe I think, nothing should fry. Really I just want to run frig., TV, lights, and maybe some fans or heater. Thanks guys I know it sounds like a stupid question but stupid is as stupid does. Transfer switches run $250+

 

[lakelandcat]

If you kill the main breaker in the shop does the house stay on or go off?

If it stays on you will have to pull the meter to power the house.

-- Carl

The following statement is just plain WRONG !



So the house is actually wired as a "sub-panel" to the shop, correct ?. The simplest solution is to install a generator interlock kit in the shop. When the generator is running and the interlock is flipped (it is actually a type of transfer switch) everything in your shop and hose will have power. Use it wisely.

Both are actually mains, to classify as a "sub panel" it would have to come out of the main house panel, this ties in after meter and before house. house and shop are not connected, except with meter. Is a generator interlock manual or auto.?

 

[Bert_]

We really need more info, it seems like both buildings are fed directly off the load side of the meter. What do you have for a meter set up? A picture would be worth a thousand words...

 

[lakelandcat]

We really need more info, it seems like both buildings are fed directly off the load side of the meter. What do you have for a meter set up? A picture would be worth a thousand words...

same meter everyone else has, just installed dual lug so 240v goes to the house and 240v feeds shop, its all legal and inspected. Pwr. comes from Elec. co into meter. After meter each leg is tied in via lug. 2 legs goes to house and 2 to shop on each side. Shop is NOT tied to house main panel. Think of it like a splice.

 

[finn]

In that case, no, you can’t do it, since you will be powering up the entire grid by back feeding your meter (and the grid) with the generator.

You are required to have isolation via some sort of lockout to protect the utility workers, and a half assed “I always remember to disconnect the mains” isn’t good enough.

In your case, that wouldn’t work anyway.

(My project house has a pass through panel mounted under the meter that has several breakers that feed the garage and yard lights, and passes power directly to themain panel in the house. If yours is wired like that, an interlock on the main breaker would disable current backflow to the grid.)

 

[Bert_]

same meter everyone else has, just installed dual lug so 240v goes to the house and 240v feeds shop, its all legal and inspected. Pwr. comes from Elec. co into meter. After meter each leg is tied in via lug. 2 legs goes to house and 2 to shop on each side. Shop is NOT tied to house main panel. Think of it like a splice.

Then you need a transfer switch right after the meter. Feed house and garage from that.

 

[PCustoms]

You have POCO-->Meter-->Garage-->House (house is fed from garage panel), correct??

You need an interlock kit at the garage that locks out the main breaker and turns on the generator breaker, which will be backfed. I believe you also need a tiedown kit for the backfed breaker.


If you have:
POCO-->Meter THEN
--> Separate line to Garage
--> Separate line to house (fed from Meter's dual lugs, NOT garage panel)

Then you need to get a transfer switch, and I believe by code you have to size the generator for the entire possible load of the house and garage.

Just in case it was missed the first time...

You can do all sorts of fancy feed loops and things to have the generator remote, but bottI'm line is you need a transfer switch to cut power at the meter. Not wOrth the $ if you are running a portable backup IMHO.

I would put a plug at the house, with a backfed breaker (don't forget the tie down!) And an interlock kit to force the main off if you have the generator on.

 

[olytdi]

From what I can decipher from your description, your setup is the same as mine. That is, power comes from the street into the meter. From the meter, the power is split to two different panels -- one for the house and one for the shop. I happen to have a 200 amp panel at each.

If this is correct, then you need to have your generator connected with a dedicated feed into your house panel and that house panel needs to have an interlock such that you cannot back-feed to the grid.

I, too, have my genset out at my shop under cover when running in a power outage (about 30 feet from the house) but run an ample-sized cord to a dedicated inlet box mounted on the house, that is wired directly to the house panel. With this setup, the house is powered but the shop is completely without power in an outage.

To have power at both the shop and the house with such a setup, one would need a separate power inlet (with a separate interlock) at the shop to prevent back feed to the grid, and a separate feed from the generator to that shop panel.

I hope I understood your setup correctly.

 

[Bretny]

I have your same sub pannel in the garage. You cant do it legaly with out running wire from your generator to your main pannel in the house.

 

[theoldwizard1]

Shop is not tied to house in series. Coming out of the meter shop goes one way and house another. If I trip main in shop I wouldn't have circuit to power.

So your meter is "double tapped" (has two outputs one for the shop and one for the house), correct ?
Then I go back to my original statement

There is no SAFE/APROVED way to do what you are asking WITHOUT PULLING MORE WIRE !

OR ...

Make the house a sub off of the shop (in series to use your words) and install a generator interlock there.

OR ...

Install a new "main" panel at the meter. This does not have to be a large panel just capable of handling the loads you have AND it must be capable of a generator interlock. Both the shop and the house are now sub-panels off of this "main" and require 4 wire connections.



The key to any type of generator power transfer is that must be physically impossible to set switches "wrong", EVEN TEMPORARILY, so that the generator might backfeed the grid.

 

[lakelandcat]

Thanks for the help, I think I'll contact my inspector, see which way he advises.