Generator wiring question

Hi,
I have a 1-1/2HP, 220v motor running from the dryer socket, all good.
I was thinking of putting in a change over switch to run the motor from the generator when the power goes out as it does regularly out here.
(Amazon.com product link shortened)
To save me dragging the gen-set out and starting it to find out what is coming out of the 240-socket, thought I'd ask here.
The house wiring uses the 3-wire 110-0-110 for the 220/240 but the gen has three pins for the 240-out. I am guessing one is Ground and the others are Neutral and 240v.
How do I go about wiring that to run the motor? An ASCII diagram would be good.
Thanks
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On 5/25/2018 10:40 AM, Dave, I can't do that wrote:

other 2 , with either hot to the neutral at 110 . Mine has a 4 wire socket , with 2 hots a neutral and a ground . I suggest you look up your model generator on the interwebs and see what the owners manual says . Out of curiosity , what's the motor do ? Just sit there and run or does it power something ?
--
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On Friday, May 25, 2018 at 9:32:00 AM UTC-7, Terry Coombs wrote:

Thanks Terry,
It is only a 3-hole twist-lock socket on the generator. Looks like I will h ave to crank it up and get the meter out. I seem to recall using it to powe r something 220/240v about 6-years back, but no idea what wiring I used.
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Dave, I can't do that wrote:

Three wires is a common generator output. You will find that you have 110 - 0 - 110 volts. Just the same that feeds into a breaker box. The fourth wire that you need is ground. On 99.9% of generators you will find a ground lug on the generator head or near the output panel. That goes to a good ground.
--
Steve W.

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Generator grounding isn't obvious because it interacts with other considerations, for instance checking for buried utility lines before driving a ground rod, or impenetrable frozen soil. https://www.osha.gov/OshDoc/data_Hurricane_Facts/grounding_port_generator.html
Neutral is the power return conductor. Ground is for safety, only carries fault current, and is connected (bonded) to Neutral only at the main breaker box, or the generator frame when it is an isolated, "separately derived" power source.
http://www.arrl.org/files/file/Technology/pdf/Portable%20Generators%20and%20OSHA%20Construction%20Standards%203-05%20 (1).pdf "In other words, a ground rod is not required and, in fact, may create a hazard."
Naval standards don't ground the neutral so that a single short won't take down the ship's power. The problem with grid power is that the pole transformer secondary could short to the 19.9KV distribution line and bring high voltage into your house if you didn't have a ground rod connected to the neutral. That isn't an issue for generators.
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I think the NEC demands those only in hospitals. Everyone else has 2 hots and a not. (safety ground w/ no current)
--
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On Sun, 27 May 2018 22:24:04 -0700, Larry Jaques


Required for ranges and driers for at least the last 10 years here in Canada - don't know abiout the backwaters of the USA>
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wrote:


"Whatever for?" he queried, from said backwater.
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On Mon, 28 May 2018 17:19:25 -0700, Larry Jaques


So you can use 120 volt lightbulbs and timers and primaries on control circuit transformers, and fan motors. and all kinds of other low power devices without (illegally) using the safety ground as a neutral, potentially making the chassis "live" - as has been done, unofficially, for decades - on both dryers and ranges.
It's a "safety" thing. They initially allowed the use of the safety ground as a neutral as a matter of expediency due to the high price of copper
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wrote:


I got used to having the neutral when I was designing lab carts with 240 V DC motors. It was very handy to have 120 V outlets out in the middle of the lab for various tasks. My last set of carts were 440V explosion proof in a classified area, so no outlets on those anyway.
I continued the practice when I built my shop, had the electricians pull 4 wire for all my 240 V. circuits. But I haven't had the need since distances are short to plenty of 120 V outlets in the shop.
I will probably relocate nearer the coast in the near future. I may end up adding 120 V outlets to the welding cart if needed at the new place.
Pete Keillor
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I was only a few feet away from another tech when he tried to measure an SCR trigger circuit floating on 120V with a grounded scope. When he flipped the power switch the entire probe exploded from the enormous current in the braid, sending him to the hospital. I was facing away and didn't see but I think his body shielded me from the fireball.
-jsw
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On 5/29/2018 8:28 AM, Jim Wilkins wrote:

Defective breaker?
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Parts of the probe remained attached. He had connected the probe ground to the SCR cathode (hot line) so he could observe the optically isolated SCR gate trigger pulse without interference from the 120V sine wave it was riding on. It was a 240V power supply so both sides of the SCRs were Hot.
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wrote:


OK, politics, like belt+suspenders. Got it. I'm going to have to ask who plugs those things into dryer outlets, too, I'm afraid.
--
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On Tue, 29 May 2018 21:00:02 -0700, Larry Jaques


A welder I had used a 120 volt fan. 240 volt welder.
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On Fri, 25 May 2018 08:40:22 -0700 (PDT), "Dave, I can't do that"

If your gen ouit is 240, nor 120/240, the motor will connect across the 2 "line out" terminals while the third terminal will be a ground - no neutral.
If it is 120/240 it will have 4 wires unless it is ANCIENT
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On Fri, 25 May 2018 08:40:22 -0700 (PDT), "Dave, I can't do that"

The reason neutral wires are called that is because they are tied to ground in the breaker panel which means there is no potential voltage between the neutral wire and the ground wire, at least in the breaker panel. So there is no neutral on the generator unless it is tied to the generator ground and the generator is grounded. I'm betting that one wire is ground and that neither of the other two wires are tied to ground, meaning that there is no neutral wire on the 240 volt output. So you really need to get out the meter and see what the 240 out really is. Eric
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On Fri, 25 May 2018 17:38:09 -0700, etpm wrote:

...

...

"The reason neutral wires are called that is because they are tied to ground" seems to me to be incorrect. True, in US wiring, neutral wires usually have near-ground voltages on them, but more generally a neutral wire is one with no current flowing in it when a system is in balance.
--
jiw

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On Sat, 26 May 2018 05:41:56 -0000 (UTC), James Waldby

In US wiring the neutral does have current running through it. Eric
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On 5/26/2018 11:53 AM, snipped-for-privacy@whidbey.com wrote:

so I corrected your statement .
--
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