Irrigation pump in lake

Would it be possible to use a spa disconnect and wire it 240v and install the GFCI breaker in it? Obviously there wouldn't be a neutral but if it's only used for the 240v irrigation pump would this be code compliant?
You must have a supply side neutral for your GFCI. What you don't need is a neutral run out with load conductors if there is no neutral load to be served. That supply side neutral powers the GFCI electronic circuitry. If you don't hook it up you have no GFCI protection and effectively turn your $100+ GFCI 2 pole breaker into a standard thermal magnetic breaker, which might only be a $20-30 item depending on which brand is involved.
 
$345 to $550 each? Talk about overkill!
Here's one that's under $200:


Cheers, Wayne
 
So in theory I could add a Square D QO spa disconnect or similar with one of those GFCI circuit breakers at the location of the pump and be good to go?
Only if you confirm that the QO circuit breaker therein does not require a line side neutral. I'm not yet aware of any that don't.

Cheers, Wayne
 
Simple. Get a three phase pump. They make VFDs with voltage doublers. 120 in 208 to 240 out. Now you can ramp it and reduce any issue you may have with VD.

Problem solved. Unless your HP is too large.

Do you think a VFD will work without tripping a GFCI? VFDs have common-mode switching noise that could aggravate concerns about leakage currents tripping a GFCI.
 
I always thought the neutral in a 2-GFCI was using the neutral for sensing something? volts to ground? Thats exceedingly stupid if its just for electronics. Has anyone cracked on open?

All GFCIs must be connected to sense every circuit conductor. If a two pole GFCI is supplying a circuit with 2 hots and a neutral, then that neutral must pass through the GFCI sense transformer or the GFCI will trip. This is required by the physics of the situation. That is the issue that you are remembering.

The issue for the present discussion is 'what happens when the load doesn't need a neutral'. If the neutral is not part of the circuit being supplied, then in principal the neutral doesn't need to pass through the sense coil. But the GFCI also needs power to operate, and most if not all two pole GFCIs use L-N for electronics power. The OP's situation is best solved with a GFCI that uses L-L power to operate.

-Jonathan
 
Do you think a VFD will work without tripping a GFCI? VFDs have common-mode switching noise that could aggravate concerns about leakage currents tripping a GFCI.
The $157.00 3/4 HP model I just looked at stated the RFI jumper must be removed for 120-volt operation. Will it work? IDK, but after 168 responses we should be hearing relatively soon what did or didn't.
 
This discussion was impressive! I can't thank everyone enough. I'll more than likely just try and wire it with a 2 pole GFCI circuit breaker first and if that has issues I'll try one of the numerous suggestions from this forum. I don't know how this works exactly but if possible I'll let you know the outcome. Thanks again. Deke
 
Oh, what model(s) of QO breakers? QO260GFCI, for example, has no load neutral terminal, but still has a neutral pigtail, so I infer it still requires 120V for its GFCI electronics.

Cheers, Wayne
You’re right, it isn’t Square D. That requires the neutral on the line side. I know I have run into at least one that did not, now I’ll have to dig further. I mostly use Square D, but it must have been on another job, so now I’ll have to root around in the half dead brain cells to try to recall which one it was. My memory ain’t want it used to be…
 
Only if you confirm that the QO circuit breaker therein does not require a line side neutral. I'm not yet aware of any that don't.

Cheers, Wayne
Even the QO 2 pole 60 amp GFCI that does not have a load side neutral terminal still needs a line side neutral to function properly. If you don't connect the line side neutral you effectively end up with a thermal magnetic breaker as the GFCI logic board operates from one pole to the neutral.
 
Even the QO 2 pole 60 amp GFCI that does not have a load side neutral terminal still needs a line side neutral to function properly. If you don't connect the line side neutral you effectively end up with a thermal magnetic breaker as the GFCI logic board operates from one pole to the neutral.
Not advocating it, but do they function if the line side neutral is taken to an EG because there is no neutral available? Not sure if someone else already asked. This is starting to be a lengthy thread.
 
Not advocating it, but do they function if the line side neutral is taken to an EG because there is no neutral available? Not sure if someone else already asked. This is starting to be a lengthy thread.
It will function.

possibly would function if you put a probe into the earth and connected to that.

I'm not advocating that either.
 
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