Generator Transfer switch connection choices

[daybreak1998]

I just don't see why the NEC would care if I overload and damage my own generator. I must be missing something.

Howdy,
They only care about a automatic overload. Circuit breakers are meant to trip when there is a fault/overload. You do not try to run a 30amp ac unit on a 20 amp breaker?

The generator has a circuit breaker itself. If you load up to much, it should trip.

 

[joshuabardwell]

I'm sorry if I'm being obtuse, and I understand that the answer may be, "Codes are nonsensical sometimes," but I still don't get it. If I install a backfeed breaker with an interlock, then I can use a portable generator to power my whole house by switching individual breakers on and off. But if I install a DPDT switch between the main panel and the meter, my generator must be permanently installed? How does that make sense?

 

[daybreak1998]

I'm sorry if I'm being obtuse, and I understand that the answer may be, "Codes are nonsensical sometimes," but I still don't get it. If I install a backfeed breaker with an interlock, then I can use a portable generator to power my whole house by switching individual breakers on and off. But if I install a DPDT switch between the main panel and the meter, my generator must be permanently installed? How does that make sense?

Howdy,
NO, you can use whatever size generator you want.

Now, if you use a fully automatic transfer switch, the genset is suppose to be big enough to run everything. I mean everything. That is total nonsense. I might run a lot of things, but I am not trying to run a upper and lower electric oven, and electric cooktop, and everything else. (kinda like thanksgiving, cooking going on everywhere)

But, a transfer switch is pricey, whether it is manual, or automatic. The interlock kit results in the same thing. Safe from backfeeding utility lines. But, the interlock kit, is way cheaper.
manual transfer switch $800, permit $$, electrician $$, utility pull meter $$

interlock kit $149, dual pole breaker sized for genset $50, wire sized for amperage to outdoor connection $50, a generator inlet kit $70, and of course your cord to hook from generator to inlet.

The nice thing is, you use your panel to shut off major power items. For instance, all electric house, turn off water heater, turn off well, turn off oven, turn off stove top, turn off electric heat. you can leave all the lights on, just don't walk around the house and turn every single one of them on. Lites themselves really do not take a lot. Its the big stuff. Then you decide what you want to run while on generator power. Just do not overload your genset. (the generator breaker will trip if overloaded) If you want to shower, turn on the well pump, ok, water pressure is up, ok, turn off well pump, now turn on water heater, after a while, water is hot, now turn off water heater, turn on well pump, take a shower.

overall concept, is safety. NO BACKFEEDING POWER LINES.

 

[RoyJackson]

... but a water heater that was heating at the time of power lost will try to start up when power is reapplied. If your generator is too small to restart your load and you forgot to turn off the breakers there's the potential problem.

That's a point and if you have an extended power outage, you'll have to consider this kind of thing. As, or more, importantly is to ensure your family knows and understands the procedure/requirements.
I can tell you now, if I was on the road and we lost power...my wife would just check into the nearest motel that had power... Hopefully, your family will be more responsive and responsible.

 

[Steave]

I just don't see why the NEC would care if I overload and damage my own generator. I must be missing something.

I was just guessing as to their reasoning. I'm not real sure why its required in some areas. It may be a local thing. In every municipality I've worked in there's something always a little different. All towns have to at least meet the requirements of the NEC but they can add their little quirps to it and to get your power turned on you have to abide by them. If you can diy without the need for inspectors (and can do it safely) then I would do it. Around here if you need the power turned off by the power company they will come out and turn it off no problem. After you do your work and call them to turn it back on is when they tell you they can't turn it on without an inspection.

 

[pat32rf]

Around here, (country) they will turn you off at the street once a year so you can do tree trimming. What ELSE you do is up to you.....

 

[Steave]

Around here, (country) they will turn you off at the street once a year so you can do tree trimming. What ELSE you do is up to you.....

Now that would be the time to get ur done!!

During storm damage here they are kinda lenient because they get to far behind if they go by the book.

 

[newbury]

In both Northern Virginia and Northeast Mississippi I've had the electric company out in the past few months, they'll drop the power so you can do tree trimming and come back later and rehook it up for free. Just give them a few days notice when they are not busy.

 

[Steave]

Howdy,
Generator transfer switch connection choices.
For safety of yourself, family, equipment and utility workers, properly connect generators.
Some methods can be do it yourself to a certain point. Electricians and your Utility will be involved as well.

Thanks for letting us bounce off your thread. If I were to hook up a genset semi permanent to the house I'd probably go with the interlock system. Even if somebody knows how to cut on and off breakers as needed it only takes a slip of the mine to BOOM! I've been called out to check wiring after power was thrown back onto a ginny, it usually just trips the breaker but... I also seen one at a large plant blow up a $750 breaker in a GE Switchgear.

 

[daybreak1998]

Howdy,
After looking around at interlock switches... if you have a mainline type panel from either GE or Square D, then the interlock kit is priced around $50 at home depot. Put in the dual pole breaker sized for your genset, proper size wire, and a inlet plug.

 

[newbury]

Howdy,
After looking around at interlock switches... if you have a mainline type panel from either GE or Square D, then the interlock kit is priced around $50 at home depot. Put in the dual pole breaker sized for your genset, proper size wire, and a inlet plug.

Link
Search Results for interlock at The Home Depot
appear to be very panel specific.

 

[Charolais]

I use a PTO generator rated at 50 amps. I got a mechanical interlock for the service panel. It's 200 amp and GE brand. I put that in back in 1983. Couldn't find the slide interlock for that style as they have changed over the years. I got measurements and kept looking at different interlocks till I found one that was close enough to use. Had to mill it in the slots to extend the length a little and cut the tab that blocks the generator breaker to make it fit. It works good.

 

[stonypass]

It's 200 amp and GE brand. I put that in back in 1983. Couldn't find the slide interlock for that style as they have changed over the years. I got measurements and kept looking at different interlocks till I found one that was close enough to use. Had to mill it in the slots to extend the length a little and cut the tab that blocks the generator breaker to make it fit.

Does your panel have a vertical Main Breaker?
Our house was built in 1994 and we have a GE PowerMark Plus 200amp 30 space load center.

I'm looking for an interlock to fit it but the GE model THQLLX1 appears to be for PowerMark Gold models.
Generator Interlock Kit from GE | The Home Depot - Model THQLLX1

If yours is similar to mine could you post pic's and a link to which interlock you started with?

Thanks.

 

[Charolais]

Does your panel have a vertical Main Breaker?
Our house was built in 1994 and we have a GE PowerMark Plus 200amp 30 space load center.

I'm looking for an interlock to fit it but the GE model THQLLX1 appears to be for PowerMark Gold models.
Generator Interlock Kit from GE | The Home Depot - Model THQLLX1

If yours is similar to mine could you post pic's and a link to which interlock you started with?

Thanks.

I bought mine in 1984. It's 40 space load center. Looks similar to yours but has one extra slot at the top on each side that says not to remove and has a vertical main breaker like yours. I used an interlock that was for a SquareD K5410 and modified it.

I used Generator InterLock Kit and look at Generator InterLock Kit - General Electric Kits K-8110 that perhaps will fit your panel.

 

[JoeL4330]

Howdy,
NO, you can use whatever size generator you want.

...

you use your panel to shut off major power items. For instance, all electric house, turn off water heater, turn off well, turn off oven, turn off stove top, turn off electric heat. you can leave all the lights on, just don't walk around the house and turn every single one of them on. Lites themselves really do not take a lot. Its the big stuff. Then you decide what you want to run while on generator power. Just do not overload your genset. (the generator breaker will trip if overloaded) If you want to shower, turn on the well pump, ok, water pressure is up, ok, turn off well pump, now turn on water heater, after a while, water is hot, now turn off water heater, turn on well pump, take a shower.

overall concept, is safety. NO BACKFEEDING POWER LINES.

Some breakers are SW rated, and meant to be used as switches as described ...others, not so much. Just a thought

 

[cqaigy2]

Some breakers are SW rated, and meant to be used as switches as described ...others, not so much. Just a thought

That's good to know.

 

[daybreak1998]

Some breakers are SW rated, and meant to be used as switches as described ...others, not so much. Just a thought

Howdy,
Circuit Breaker Switches?

Out of maybe 6 times a year needing to run on generator power, you think a circuit breaker can't handle being shut off 1 day and maybe being turned on a day later when normal power is back on.

I have not heard of any circuit breakers not being able to switch off and on a few hundred times.

between having GE panels and breakers, Milbank panel and breakers, Murray panel and breakers, Square D panel and breakers, and some siemens breakers out there also. Standard breakers, GFCI breakers and such, I have never had failure with a circuit breaker. But, I am not flipping them off and on 20 times a day either.

 

[daybreak1998]

Howdy,
This was brought up in another thread which showed some products with good prices from local sources.
GE Power Mark Gold 200 Amp Main Breaker 4-Space 8-Circuit Meter Socket Load Center and the matching GE PowerMark Gold Generator Interlock Kit really is a nicely priced outdoor NEMA 3R meter base with generator interlock ability. With this being at the meter, you can control it with this service disconnect and then still have your main panel inside with service disconnect as well.

NOTE: always check with your Utility service to see if this is acceptable for service. They have the say so since it holds the meter.

 

[aczlan]

NOTE: always check with your Utility service to see if this is acceptable for service. They have the say so since it holds the meter.

FYI, I asked both NYSEG and RG&E about this via their websites and I just heard back from NYSEG. Here is what they had to say:

After reading through the request I just calling to advise you that the inspectors are ultimately the ones that make the decision on whether or not your work is performed up to code, so if there indicating to you that the equipment that you're choosing to use is acceptable, it is okay to go with the inspectors advice. They're the ones that are going to inspect the service and submit the U L certificate to us to let us know what was done up to code and done safely and we just accept that from them. If we were go by and we were to find something that was grossly un safe that they didn't notice, certainly we would make you make corrections to that but ultimately the inspectors our our final word as far as whether or not the service is unacceptable.

Still waiting to hear back from RG&E (who actually owns the meter).

Aaron Z

 

[hr3]

FYI Ring type meters are not allowed in some states...