Lost one of the 120V legs going to my shop

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  #1  
Old 06-30-15, 01:35 PM
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Lost one of the 120V legs going to my shop

I have 2 40 amp breakers in the panel for the house that feed my shop. I checked the voltage at the sub panel in the shop with 8 Square D breakers and 1 120 volt leg has power, the other shows 0 voltage. I then go to the main house panel and check voltage on the 2 40 AMP breakers and I am getting 120 volts from the breaker to neutral and 220 at both breakers. Looks like I lost one of the under ground 120 Volt feeders that feeds my panel in the shop.

I will dissconnect the 2 wires in the main house panel, tie them together, disconnect them at the shop panel and check for continuity. If it is open, one of the feeders is bad. Correct in my thinking??

OK what type of wire should I use for underground direct burial? I can't find out what all the letters mean. I am looking to pull a #8 wire 115 feet. If I can pull the old wire out, I will use the same conduit. If I can't, I will have to pull into the attic, across the house and outside, then bury the rest of the way to the shop.

Thanks
BUD
 
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Old 06-30-15, 02:57 PM
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I have 2 40 amp breakers in the panel for the house that feed my shop.
Should be one two pole breaker. Is that what you meant?
1 120 volt leg has power, the other shows 0 voltage.
There are twp 240 legs. 120 come from one of the 240 legs and neutral so you have a dead 240 leg.
I will dissconnect the 2 wires in the main house panel, tie them together, disconnect them at the shop panel and check for continuity. If it is open, one of the feeders is bad. Correct in my thinking??
Yes, that is correct and since you have 120 one of the 240 legs is open.
what type of wire should I use for underground direct burial
Not sure from your post if you have cable or individual conductors. If conduit individual wires are easier to pull then cable.
 

Last edited by ray2047; 06-30-15 at 07:21 PM. Reason: Rewite original reply and correct errors.
  #3  
Old 06-30-15, 05:16 PM
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There are wires (individual conductors) that are approved for direct burial. USE would be one of them. They must be buried 24" minimum. If you are installing them in conduit you can use any wet rated wire. (THWN, XHHW, etc)
 
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Old 06-30-15, 07:09 PM
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you only need to replace the hot wire that is bad. Do your continuity test using the neutral and each hot. Try to use the bad hot to pull in the new hot.
In a 115' run there isn't much of a chance to pull a single wire out and a new one in.

You'll need to pull them all out and re-pull the bunch.
 
  #5  
Old 07-01-15, 05:56 AM
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Well, I did a lot of testing and I do have a bad 120 volt line bad. I disconnected 1 120 volt wire at a time from the 2 pole breaker. The good leg has 120 volts at the shop and at the main panel. The other leg has 120 volts at the main panel and only 30 volts at the shop. The 3 #2 wires has been in the conduit buried in the ground for 35 years, I don't think I will be able to pull them out of the conduit. I really didn't need the #2 wire when I installed it, but it was free, so I used it.

Looks like I will pull wire up into the attic, across the house, down the other side and bury the last 30' to the shop. I will be using #8 (2 blacks, 1 white, 1 red).

Thanks for all the help

BUD
 
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Old 07-01-15, 08:21 AM
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using #8 (2 blacks, 1 white, 1 red).
I hope you meant to type green!
 
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Old 07-01-15, 09:28 AM
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I do have a bad 120 volt line bad.
No, you do not. As previously written your garage is supplied with 240 volts not two 120v feeds.. One leg of the 240 volts is bad. The 120 is derived from the neutral and either one of the 240v legs from the 240v breaker.
The 3 #2 wires has been in the conduit buried in the ground for 35 years, I don't think I will be able to pull them out of the conduit.
If the conduit is EMT (thin wall metal conduit) it should be abandoned. It is not really suitable for direct burial and is probably rusted out,
 
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Old 07-01-15, 05:27 PM
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If the conduit is EMT (thin wall metal conduit) it should be abandoned. It is not really suitable for direct burial and is probably rusted out,
If the conduit is EMT I can guarantee it is rusted out.

The 3 #2 wires has been in the conduit buried in the ground for 35 years, I don't think I will be able to pull them out of the conduit.
If the conduit is PVC you can probably pull them out. Today you need 4 wires and not just 3.
 
  #9  
Old 07-06-15, 07:36 AM
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I tried to pull the old wire out of the conduit, about 2' came out and then it broke. One of the 120 volt legs had corroded in two. Ran a new #8 and all is OK. Bad part was working in the attic with a high in my area of 93 degrees F.

BUD
 
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Old 07-06-15, 09:45 AM
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I tried to pull the old wire out of the conduit, about 2' came out and then it broke. One of the 120 volt legs had corroded in two. Ran a new #8 and all is OK.
How did you get it into the conduit?
 
  #11  
Old 07-07-15, 04:43 AM
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I have concrete everywhere now and going underground would require breaking up a lot of concrete. The only other choice was to go overhead. I went up into the attic and then overhead to my shop.

BUD
 
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Old 07-07-15, 07:41 AM
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Do you mean you ran 4 wires overhead? You can't run just one because all conductors must be in the same raceway so if any are all must be.
 
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