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We just had a major electrical outage in our area and I was too slow in my search for a 30A 240V male plug. The generator I was borrowing had a 240V plug and 2 120V plugs. I assumed the 2 120V plugs were either side of the 240V with a common neutral. Since the house is wired with a 30A 240V outlet connected to a transfer switch I tried wiring the 2 120V plugs using the 2 different hot legs and combining the neutral and ground to outlet on the house. The generator did not like this. The generator had a switch that said 120V on one side and 120V-240V on the other. When on 120V the breaker on the generator took about 5-10 seconds to trip with both 120V plugs. When switched to 120V-240V the breaker would not even engage. I ended up pulling one of the 120V plugs off and only powering one side of the transfer switch. All is good now with power back but I am curious on how these generators are wired. Major snow storm coming tonight through Wednesday, hoping the last people get power back today.
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I use the 220 twist lock plug on my generator and also a twist lock plug to the receptacle attached to the house.The wire runs through conduit into my basement to the transfer switch.I had an electrician bridge the two panels and wire the circuits I wanted into the generator panel.When the power goes out,simple matter of switching off the main panel and rotating a dial and switching on the generator panel.Start the generator and life is good.As far as I know the 120 volt plugs on the generator are for extension cords only.It is not possible for the two panels to be activated at the same time,as there is a lockout switch in the generator panel.
Mel
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I emailed my BIL for the specs on the generator. It was an off brand 4.4KW regular generator no inverter. When my BIL responds I can get more detailed.
Mel, That is the same set up I have but never got the generator so I never had the cord to connect the generator to the house. My BIL had a generator but left the cord in Maine about 10 hrs away. By the time I was making up the cord all the male plugs were sold out. I think in the future I might get an interlock for the main panel so I have access to the power where ever I want it in the house.
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I couldn't say how yours is wired, but the 120V duplex receptacle on my Generac 4kVA portable is split, with the hots to the two 'phases' and the neutrals common. The equipment ground lugs are also bonded to the neutrals. And there's an L14-30 twist-lock receptacle, too. No switches of any kind, other than on/off and automatic idle (and breaker resets).
You should have a schematic in the documentation, and if not, you may be able to find it online.
But I installed a generator panel a decade ago, so I don't have to think about it any more.
Tom
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(03-13-2017, 09:22 AM)Bope Wrote: Since the house is wired with a 30A 240V outlet connected to a transfer switch I tried wiring the 2 120V plugs using the 2 different hot legs and combining the neutral and ground to outlet on the house. The generator did not like this.
240V (3-wire)? Or 120/240V (4-wire)?
Tom
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(03-13-2017, 10:33 AM)TDKPE Wrote: 240V (3-wire)? Or 120/240V (4-wire)?
120/240V 4 wire. Did you keep warm this weekend? We were back Sat. afternoon.
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(03-13-2017, 10:38 AM)Bope Wrote: 120/240V 4 wire. Did you keep warm this weekend? We were back Sat. afternoon.
We never lost power. The lights blinked a couple of times, just enough to mess up the oven clock and make my computer's UPS kick in, but that was it.
Folks in Irondequoit had it the roughest, from what I understand. Winds came off the lake, and they were first in line for the fun. 10,000 still without power, but 115k were out at one time.
Tom
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On a generator with a 120 or 120-240 selector switch, when in the 120v position it places the two windings in parallel, with full power available to the 120v outlet but no 240v anywhere. When in the 120-240v position it places the windings in series so then the full power is available on the 240 outlet and basically 1/2 power on each of the 120 v circuits. Not understanding why it did not work in 240 position unless generator has some sort of lockout to prevent switching while running. Roly
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03-14-2017, 10:17 AM
(This post was last modified: 03-14-2017, 10:17 AM by mound.)
You must be from my town (Rochester)
I had no power from wednesday at 1pm until Sunday night at 9pm and the snow has started!
