I have been asked by a homeowner to find a way to power his home with a generator. He has a limited budget and has a 200-amp service that comes into the dwelling. One of the major downfalls of the building is the fact that it has three electrical panels all feeding off the same meter. It used to be three small apartments and they did a limited remodel.
I had an idea that the owner would go for, but I think it might have a code violation in it.
My proposal is two install a 200 amp, double pole, double throw, non-fused transfer switch. The utility company in this area has some pretty exact guidelines on how to bond and the use of transfer switches. They want to see all neutrals bonded in the switch. Utility power and generator power. The major question that is bothering me is the on the generator side of things. The want to power up the building with a 9Kw generator, 240-volt, 100% duty cycle. I explained the fact that this would not be enough to run the home and they understand. The thought that I had, since they have a few critical loads branch ckts coming out of each of the three panels is to identify those loads, (oil fired forced furnace, outlet ckt, a few lights) and have those marked in the ready. At the time of a major power outage, they can go around a shut down all but those critical loads at each of the panels. At this time they can fire up the gen. and switch over power with the DP, DT Trans Sw and keep the critical loads running.
Question: you have OC protection on the utility side going into the Trans switch. Utility power goes through a 200-amp breaker. The generator has a two pole, 240 volt, 30 amp breaker on it for over current protection.
If you ran 200 amp protected wire into the trans switch for the utility side and also for the common side, could you use the over current protection on the generator as adequate protection to size your wire for the generator feed? My thought was of course is to run 2/0 into the switch for the utility side, the common, and also the generator side. On the Generator side I would run 2/0 into the switch, but beside the switch I would mount a Nema 3R box and use a tap to connect the 2/0 to SOW Cord with the appropriate cord end that fits into the generator.
In the event that the generator is overloaded, and with this installation it very well might be if they push it, the wire and plug are sized for the generator and should be sized correctly.
Does this sound like it should work. I guess the big question is if the generator OC protection is adequate and meets the NEC code requirements.
Thanks in advance.
I had an idea that the owner would go for, but I think it might have a code violation in it.
My proposal is two install a 200 amp, double pole, double throw, non-fused transfer switch. The utility company in this area has some pretty exact guidelines on how to bond and the use of transfer switches. They want to see all neutrals bonded in the switch. Utility power and generator power. The major question that is bothering me is the on the generator side of things. The want to power up the building with a 9Kw generator, 240-volt, 100% duty cycle. I explained the fact that this would not be enough to run the home and they understand. The thought that I had, since they have a few critical loads branch ckts coming out of each of the three panels is to identify those loads, (oil fired forced furnace, outlet ckt, a few lights) and have those marked in the ready. At the time of a major power outage, they can go around a shut down all but those critical loads at each of the panels. At this time they can fire up the gen. and switch over power with the DP, DT Trans Sw and keep the critical loads running.
Question: you have OC protection on the utility side going into the Trans switch. Utility power goes through a 200-amp breaker. The generator has a two pole, 240 volt, 30 amp breaker on it for over current protection.
If you ran 200 amp protected wire into the trans switch for the utility side and also for the common side, could you use the over current protection on the generator as adequate protection to size your wire for the generator feed? My thought was of course is to run 2/0 into the switch for the utility side, the common, and also the generator side. On the Generator side I would run 2/0 into the switch, but beside the switch I would mount a Nema 3R box and use a tap to connect the 2/0 to SOW Cord with the appropriate cord end that fits into the generator.
In the event that the generator is overloaded, and with this installation it very well might be if they push it, the wire and plug are sized for the generator and should be sized correctly.
Does this sound like it should work. I guess the big question is if the generator OC protection is adequate and meets the NEC code requirements.
Thanks in advance.
