portable generators

[codeunderstanding]

This customer has a 200 amp service at ther house and they also have a pole barn with a 90 amp sub panel. They want to use a generator to run some loads in there house. Instead of putting the generator at the house they want to put it at the pole barn and back feed the feeder for the sub panel up to the house. I cant figure out in my head and trying to on paper to make this work legally with those manual transfer switches and make up boxes unless the make up box is at the house. Has anyone did it this way or have a wiring diagram of how it could be done?

 

[barbeer]

In theory and probably in the field it will work, BUT I do not believe that this installation will meet all provisions of minimum code.

 

[charlie b]

I don't know what a "make up box" is, so that part I cannot address.

My problem is that I don't know how this setup can prevent backfeeding all the way to the utility power lines, and killing a lineman. OK, so perhaps the HO will remember to open the main breaker, before backfeeding from the garage to the house. Perhaps not. It's not safe. Offhand, I can't name an article that it would violate. But the purpose of a transfer switch is not just to transfer loads, but also to prevent interconnection of power sources.

 

[codeunderstanding]

I don't know what a "make up box" is, so that part I cannot address.

My problem is that I don't know how this setup can prevent backfeeding all the way to the utility power lines, and killing a lineman. OK, so perhaps the HO will remember to open the main breaker, before backfeeding from the garage to the house. Perhaps not. It's not safe. Offhand, I can't name an article that it would violate. But the purpose of a transfer switch is not just to transfer loads, but also to prevent interconnection of power sources.

The make up box is the transfer switch that has the selected loads prewired that you can select to power up when the power goes out.

I'm with you I dont think it will work that way that they want it. They are going to have to put the transfer switch at the main service and are going to have to wheel the generator to the house to plug it in.

 

[haskindm]

I agree. It would be fairly simple to install a "generator panel" and transfer switch at the barn and backfeed the feeder to the house, but you also need to disconnect the house from the utilty power. The only possible way would be to have the utility bring the power to the barn first and then feed the house from the barn, but that would be a major rewiring project.

 

[coulter]

In my work it would neither be illegal nor unsafe - just cost some money.

It's an accounting issue. Is it cheaper to put in the long generator feeder, or to install the equipment to handle the backfeed?

carl

 

[coulter]

...I cant figure out in my head and trying to on paper to make this work legally with those manual transfer switches and make up boxes ...

I can't either. You may have to go with auto switches and interconnected relaying.

carl

 

[John Valdes]

I use a sub panel in my basement to feed the main upstairs. The generator is connected to a breaker in the sub panel. I have a lock out (manual type) that will not allow me to turn on the main panel breaker without the generator breaker open, eliminating the need for a transfer switch. Then I just pick and choose what breakers I want to use during a power outage. No need for a make up box? at all.
I identified all the breakers and made certain where they went and also the current required for each one. Since I know the limitations of the generator I know what I can and cant run at the same time.

 

[codeunderstanding]

I use a sub panel in my basement to feed the main upstairs. The generator is connected to a breaker in the sub panel. I have a lock out (manual type) that will not allow me to turn on the main panel breaker without the generator breaker open, eliminating the need for a transfer switch. Then I just pick and choose what breakers I want to use during a power outage. No need for a make up box? at all.
I identified all the breakers and made certain where they went and also the current required for each one. Since I know the limitations of the generator I know what I can and cant run at the same time.

Where did you get the interlock for the main panel that works with the generator breaker. Is that a listed transfer equipment.

 

[tom baker]

Where did you get the interlock for the main panel that works with the generator breaker. Is that a listed transfer equipment.

All the major panel mfgs have them, and yes they are a listed transfer switch. I just installed one from Siemens...the wholesale house can't keep in stock.