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Old 06-10-2011, 11:54 PM   #1
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240V Circuit Problem


I have a problem that I have been looking at too long, and I need some help with it now.

Main panel feeding GFCI disconnect spa panel. At main panel, 240V acquired.

At GFCI spa panel, 120V on one leg, 40V on the other.

Main panel - 50A breaker (red and black)
Ground and neutral hooked to ground bar

GFCI disconnect - 50A GFCI breaker (red, black, and white going to load)
Red and black from main panel hooked to lugs, neutral from panel hooked to breaker at white dot, neutral pigtail hooked to neutral bar as well.

I am missing something and I cannot figure out what it is.

Someone please help!! Thanks!!

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Old 06-11-2011, 06:52 AM   #2
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240V Circuit Problem


Quote:
Originally Posted by thomassayle View Post
....
GFCI disconnect - 50A GFCI breaker (red, black, and white going to load)
Red and black from main panel hooked to lugs, neutral from panel hooked to breaker at white dot, neutral pigtail hooked to neutral bar as well.

I am missing something and I cannot figure out what it is. ...
Your problem is highlighted in red:

The neutral from your main panel does not hook to the GFCI breaker. It should be connected to the neutral bar in the spa panel. The breaker gets its neutral feed through the attached pigtail from there.

The load neutral connects to the white dot terminal on the GFCI breaker.

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Old 06-11-2011, 07:33 AM   #3
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240V Circuit Problem


Told you guys I was looking at it too long. So long that I even typed it in wrong.

Okay, let me try again.

Main panel feeding GFCI disconnect spa panel. At main panel, 240V acquired.

At GFCI spa panel, 120V on one leg, 40V on the other.

Main panel - 50A breaker (red and black)
Ground and neutral hooked to ground bar

GFCI disconnect - 50A GFCI breaker (red, black, and white going to load)
Red and black from main panel hooked to lugs, neutral from panel hooked to neutral bar, neutral pigtail hooked to neutral bar as well.

I have removed the spa wiring out of the panel for now while I figure out what is wrong.

Red wire to ground, 125V. Black wire to ground, 43V.

240V at main panel though at backside of breaker.

Something is not right.
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Old 06-11-2011, 08:38 AM   #4
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240V Circuit Problem


The black wire has a loose or open connection somewhere. Maybe the cable has been damage by a nail, screw, rodent? Are the connection tight in the main panel? Are there any junction between the two panels.
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Old 06-11-2011, 09:00 AM   #5
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240V Circuit Problem


Reverse your black and red wires. Does the voltage change to the other leg?


You could have a bad breaker, or bad wire -- these measurements should tell which is witch.
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Old 06-11-2011, 09:02 AM   #6
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240V Circuit Problem


Main panel feeding GFCI disconnect spa panel. At main panel, 240V acquired.
At what point did you take this measurement? At the busbars or the output of the breaker? Verify the terminals are tight, power off. Verify the breaker is seated properly. Make sure to test the output of the breaker to verify 240V is leaving.

At GFCI spa panel, 120V on one leg, 40V on the other.
At what point did you take this measurement? Verify the terminals are tight (power off), then test the voltage at the busbars. Verify 240V is entering.

Red wire to ground, 125V. Black wire to ground, 43V.
At what point did you take this measurement? Output of the spa disconnect? Again, verify the terminals are tight, power off. Verify the breaker is seated properly. Test the output of the breaker. Verify 240V is leaving.

240V at main panel though at backside of breaker.
What’s this mean? The main panel busbars?

These steps should reveal where the problem lies.
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Old 06-11-2011, 09:03 AM   #7
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240V Circuit Problem


Also good ideas joe & kb...
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Old 06-11-2011, 12:40 PM   #8
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240V Circuit Problem


Okay, so everyone can laugh at me now.

I figured out what the problem was.

So, I decided to do some troubleshooting. First, I removed the black wire from the breaker and connected it to the ground bar.

I then went to the disconnect panel and attempted to run a continuity test to ensure that something was not wrong with that wire.

As soon as I took the wire off of the breaker, I knew what the problem was.

Instead of making the proper connection to the breaker, the black wire slipped behind the lug and had not made the proper connection.

Fixed that and working fine. I had looked at that panel for so long and thought about so many things that I got frustrated and just could not think anymore.

I was thinking about resistive neutrals, voltage bleed, all kinds of things.

Thanks for all the help. Your responses made me sit here and think about what the problem could be instead of staring at the panel for hours.

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