Generator Bypass (here we go again! :+)

[Jay]

Our power flicked out for a few hours this weekend, and that reminded me it was time to install my generator panel. I completely understand and agree there must be a foolproof wait to prevent backfeeds. In the past, I had thought that pulling the main breaker was sufficient (is it?), but that does not meet the "legal requirements".

Anyway, I have no trouble with an enforced bypass that will not allow the generator to feed back onto the grid.

However, most transfer panels I see require an additional subpanel with the "generator powered cicuits" ran through them. This limits my flexability quite a bit.

What I'd like to do is power my entire EXISITING panel from either the generator or the grid. Hence, when power goes out, I throw a switch that cuts the entire grid connections (2 hots and the neutral) over to the 4 prong generator hookup.

As for a 5500 watt generator powering my home, I turn off everything but what I want to run. And it is my problem if I trip the 30A breaker which now replaces the 200A main.

Has anyone heard if the "powers that be" (a/k/a the Government) will allow such a setup? Or will I run up against code (NEC or otherwise) that will not allow this. Again, I do not want to be able to backfeed and I want a safe generator tie in. However, I do want the flexibility to select what I power in my house from all the breakers on my panel.

Any electricians have thoughts on this one?

Thanks, Jim

PS: I have a BS in Electronic Engineering (not to blow my own horn, just o explain that you can "talk shop" if need be regrading load balances on the generator phases and all that stuff).

[Ron]

You can install a service rated 200A manual transfer switch (aka two pole double throw switch) ahead of the 200A panelboard. This would require interfacing with the utility folks to terminate, and you need to rework the location of the neutral to ground bond from the panelboard to the switch. Another choice, which I have done, is replace my 200A panel, with one that has an interlocked 200A main and 30A main. Like a TTV2003C from

If you happen to have a Square D QO panelboard currently, you can add a 30A main interlocked with the 200A main. The interlock is a nice accessory only for that panel from Square D.

[Jim]

Ron,

Thanks for the quick response. Lots of leads to follow here (no pun). Now I only need to find an electrician that will do my bidding. (My DIY stops at the main breaker. :+)

My box is a Cutler-Hammer with a 200A service. I am not yet sure of the model as I have not spent much time "inside"...yet.

Thanks aga> You can install a service rated 200A manual transfer switch (aka two pole

[Jim]

Ron,

Thanks for the quick response. Lots of leads to follow here (no pun). Now I only need to find an electrician that will do my bidding. (My DIY stops at the main breaker. :+)

My box is a Cutler-Hammer with a 200A service. I am not yet sure of the model as I have not spent much time "inside"...yet.

Thanks aga> You can install a service rated 200A manual transfer switch (aka two pole

[Nick Hull]

Another thing to consider is with a subpanel you will know when commercial power comes back on, if everything is on the generator you don't know when the power came back.

[Jim]

Nick,

I will know power is back on when the neighbor's stop asking to use our shower and their lights come back on. :+)

The trade off I want to avoid with the subpanel is that I cannot pick any circuit in the house, just the ones which run through the transfer subpanel. Between the fridge, well pump, dual zoned air handlers and several electrical outlets, my choices will vary which of these I want to run at different times. Not to mention the other circuits I add later when I get the remodeling bug in the electrical department.

I know enough to turn off all the circuits when first cutting over to the generator, then selecting the circuits I need/want to be powered. I simply want to choose from any and all of the circuits (hence my main panel).

I guess I can also look at the meter to see when the grid comes back on. Perhaps a transfer switch also has some indicator (neon light or something).

I definitely want to meet code, and not threaten utility workers. However, I want to maintain as much flexibility as possible. My only hope is that only the utility workers health (backfeed prevention) is in code, and the rest (subpanels) is a choice for the homeowner.

Thanks for the reply... Jim

Nick Hull wrote:

[Chris Lewis]

According to Jim :

The reasons for the current rules is that the utility companies/regulators don't trust you (and especially the next owner of the home) to ALWAYS remember the proper sequencing, especially in a real emergency (long term outage, at night, you have to get the heat going again, and the chilluns are screaming that it's dark and they're scared...)

The reality is also that in an emergency they'll forgive just about anything AS LONG AS nobody gets zapped[+]. But they're not going to like a permanent installation that was done wrong when you had ample opportunity to get it right _before_ the emergency.

Other posters have mentioned main transfer switches. The main disincentive is that they're (usually) more expensive than a transfer subpanel, and a subpanel is easier for a DIYer to install. But they seem the right answer in your case.

[+] Like one interconnect we saw during the great ice storm. Electrician had wired the main breakers off. Ran a 240V 4-wire circuit from the generator. He didn't have 4-wire (12/3). So he ran two 12/2 cables. He didn't have a plug for the generator, so he stripped the ends of the cables, bent them into a "prong like" tip, and jammed them in the generator socket. On the panel end, the cables were _directly_ bolted to the buss bars. Took us a bit to figure it out (power had come back and we were asked to remove the feed).

[Joe Fabeitz]

Oh Really? And what would you expect to see "...looking at the meter"?

a BS in Electrical Engineering...doh!

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