I've got a generic Champion portable backup generator that is doing its job, warding off power outages. To use it, I would simply run an extension cord and plug in whatever I need to plug in.
Done that way, the ground and return line is a closed circle to the generator, that is sitting on its rubber feet. There is no direct connection to ground.
Currently, the furnace and well can be unplugged and plugged into the generator. That should work just fine.
Here's my question. Can I change the furnace and well using a heavy 3-way switch on the hot leg, and have the panel box neutral and ground be connected to the generator? With the switch, just like with the plugs, at no time would the hot leg of the generator ever be connected to the main power.
It seems to me I could, and that it should be better for safety, especially with the grounding. But I'm suspicious I'm missing something and could cause a problem I'm not aware of.
So those of you who play with this stuff, am I off base or would this work and be safe?
Of just leave it as a plug switching where there's essentially never a chance of screwing things up?
As I recall installing my 200 amp whole house switches (I have 2), the neutral is not switched, just the two hot legs.
Of course, the safest thing is to keep doing what you're doing and just plug stuff into the generator, but I think if you switch the two hot legs, you should be OK.
Here's a schematic showing a transfer switch.
You can see that the switch is double pole double throw and the neutral is not switched. The neutral and ground are the same in a 220V system.
DISCLAIMER: I am a lot of things but not a professional electrician.
cwh
PowerDork
2/3/16 7:23 p.m.
STRONGLY suggest calling a generator pro. This is far too dangerous to screw with without good training. Burn your house down dangerous
Is there something preventing you from tapping into the house's ground at it's ground rod and connecting to the generator ground lug? Add a connector of some sort to the gen and house ground and it would set up real fast.
IMHO you want to do this properly with a transfer switch (i.e., designed for the purpose, not just a random heavy duty switch) and a qualified electrician.
This for sure. I'd do it for you if I were closer.
IIRC portable generators of that size don't need to be grounded, but I'd have to look it up.
NGTD wrote:
codrus wrote:
IMHO you want to do this properly with a transfer switch (i.e., designed for the purpose, not just a random heavy duty switch) and a qualified electrician.
Yeah this!!!
That's so funny, I was just about to ask a similar question! I wanted to be able to plug furnace into the generator using a cutout switch, and not wire in a transfer switch to the breaker panel.
I hooked up two light switches in a junction box, each cutting out the hot with the neutrals tied together. The idea was that with both switches down, the line in from the generator was not connected, and with both up the line from the house was not connected. (This was to ensure that no juice went out to the lines during a blackout) Seemed like it would work, but I had a constant 20v at the line to the generator even with the switch off.
My best guess is that a light switch does not really cut the juice 100%, or that the common neutral is bleeding juice...didn't matter I just took it out. I have no desire to zap myself or burn down the house.
A 20 amp switch is a 20 amp switch. So the capacity of the switch is a non-issue. Especially for turning on the likes of a little circulator pump.
My wiring thoughts are correct. As shown in Dr. Hess's drawings, and the wiring drawings of my generator, and the wiring instructions from NEC. So that's good too.
BUT... Huge change in liability and insurance when I hard wire in the generator with switches vs using plugs. That I had known, but had forgotten.
So, just not worth it to me. Staying with the plugs.
Probably will ground the generator itself. That is worthwhile, and if done at the generator instead of in the house, helps keep the separation complete and clear. While not strictly necessary, the generator is rigged for grounding.
