ECN Forum Forums Code Related Discussion NEC & other Code issues Another HO generator question.

Greg:
Jumping in here late into the conversation, have you given any thought to a manual transfer switch? Sq D used to make low amperage, double pole, double throw switches.

Just a thought

The main problem with a typical generator transfer panel is the amount of rewiring necessary to get all your loads over to the transfer panel. I really don't have the wall space for a 200a switch.
I also have the same problem as the neighbor in the 225 thread, I have loads in 2 buildings I want to serve.
Both of us have the pumps running off a panel in the garage.

For me, the main breaker interlock seems to be the easiest listed/legal solution. I really just have to swap a couple breakers around and add one for the generator input (with a retainer clip )

Greg:
Perhaps I was not clear. In lieu of a snap switch as discussed above, I mean the DPDT manual xfr switch.

Yes, a 200 amp is large for your situation and needs big space. The interlock plate solves a lot of problems for a lot of folks.

That idea came from my neighbor. I am still not sure what he is going to do.

BTW Dale Electric has a Siemens 60a transfer panel on sale for $44. I looked at it but I still can't figure out how I could wire it up in my situation. I would certainly be looking at that same situation of multiple circuits/feeders between buildings. It would even be harder for me than the neighbor. I would probably end up with 2 transfer panels and having to bury another feeder out to the garage. Suppose I could sneak a couple #10s in the current raceway with the house feeder from the generator but that would open another question. Would you have to derate?
It is a non-coincidental load.

When I was first learning the trade, the boss was most insistant that there be BOTH a mechanical and electrical interlock to prevent back-feeding - similar to what you see on a reversing motor starter.

So, we tied the breakers together for the 'mechanical' interlock. We also set up a pair of contactors so that the coil would energize (connecting generator power to the panel) only if both the generator was running and the house power was off. This was the 'electrical' interlock.

I Guess that all depends on whether you trust the service disconnect to actually disconnect all ungrounded conductors.

As far as I am concerned, If I trust it to protect me on the load side, I believe it will protect everyone on the line side.

I do believe it has to be a special circumstance that even allows back feeding the grid. My thought is when the average homeowner generator hits the locked rotor of a neighborhood full of air conditioner and refrigerator compressors the generator will kick out or burn up.
That is plenty of reason to insure you are transferring the load tho.