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Weird 3 Phase Electrical Problem

Buzzie8

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I lost one leg of my three phase at my wash this AM. The power is good from transformer but I lose one leg at the service box where the meter is located without any load. I have an underground service through 3" conduit. Power company seems to think wire burned underground or was somehow compromised. What's weird is that the exact same thing happened last year during the first big snow and drop in temp and the it somehow miraculously fixed itself a day later when the temperature went above freezing. I am wondering if ground is shifting. There are old coal mines underneath my wash. Weird stuff!
 

mjwalsh

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I lost one leg of my three phase at my wash this AM. The power is good from transformer but I lose one leg at the service box where the meter is located without any load. I have an underground service through 3" conduit. Power company seems to think wire burned underground or was somehow compromised. What's weird is that the exact same thing happened last year during the first big snow and drop in temp and the it somehow miraculously fixed itself a day later when the temperature went above freezing. I am wondering if ground is shifting. There are old coal mines underneath my wash. Weird stuff!
Buzzie8,

I would ask the Power Company to put a monitoring device with the meter ... since it sounds intermittent. From experience, they are usually anxious to do it for free. The quicker you get it resolved the better!

mike
 

pitzerwm

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You are talking about a cable the size of your thumb, they just don't separate and then "heal" themselves. I'd say a loose connection at the transformer. if not at the meter base
 

Buzzie8

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OK, show up this AM to meet electrician. All three phases working again. Temperature 35 degrees, sunny, snow melting, the exact same thing that happened to me last year. A real head scratcher.
 

Randy

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We recently pretty much had the same thing happen. It turned out to be water in the conduit. Blew down the conduit and the problem went away, after blowing gallons of water out of the concuit.
 

Buzzie8

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We recently pretty much had the same thing happen. It turned out to be water in the conduit. Blew down the conduit and the problem went away, after blowing gallons of water out of the concuit.
I was thinking that it might be water problem as well. I am not sure how to blow water out of 200' span of 3" conduit though.
 

Washmee

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I was thinking that it might be water problem as well. I am not sure how to blow water out of 200' span of 3" conduit though.
Maybe rent a big compressor. Like the ones they use for jackhammers.
 

mac

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I kind of like the water in the conduit theory, only because I've demoed some washes and pulled wet burned wire out of a lot of underground conduit. Unfortunately though that is now what is happening here. When it freezes the depth of frost takes days or weeks to reach the depth where the conduit is. The transformer box seems the culprit. If the power company won't change it just plunk it with a .22 till they do.
 

Buzzie8

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I kind of like the water in the conduit theory, only because I've demoed some washes and pulled wet burned wire out of a lot of underground conduit. Unfortunately though that is now what is happening here. When it freezes the depth of frost takes days or weeks to reach the depth where the conduit is. The transformer box seems the culprit. If the power company won't change it just plunk it with a .22 till they do.
Mac,
The only problem with blaming the transformer is that the power company is pulling 120V from all three legs on stripped back wire on the pole in front of my wash. It then goes directly into the conduit underground. Then when they check my meter box it was previously only pulling only 10V from one of the legs. It's been good for two days now. Crossing my fingers that it doesn't happen a third time.
Buzz
 

Buzzie8

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Snowing like crazy this AM. Show up at wash and lost one leg of the three phase again. What to do? What to do?
 

Washmee

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Snowing like crazy this AM. Show up at wash and lost one leg of the three phase again. What to do? What to do?
Buzz, I wonder if the snow really has any influence at all. I would just blame the cold temps we are having right now. The cold temperature has to be causing a loose connection on that leg somewhere. Is it the same leg every time? Has the power company or your electrician opened up the meter box and inspected every connection? Has the breaker on the pole ever tripped? I hate random electrical problems.
 

Buzzie8

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Buzz, I wonder if the snow really has any influence at all. I would just blame the cold temps we are having right now. The cold temperature has to be causing a loose connection on that leg somewhere. Is it the same leg every time? Has the power company or your electrician opened up the meter box and inspected every connection? Has the breaker on the pole ever tripped? I hate random electrical problems.
I just got off the phone with a golfing buddy of mine who is a retired lines man for the power company. He is convinced that it is a loose connection as well. Most likely the neutral because it is a different leg this time and we were getting wide varying voltages from the other legs a few days ago. He is going to meet me there tomorrow to check it out. I need his high voltage gloves, or I would do it tonight. I'll let you know.
 

MEP001

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I had an issue at an older wash I operated, it wasn't a loss of a leg but it was definitely a bad connection. I called the city out twice and they just took a quick look and said everything was fine. I got on the roof and tested across the common connection to the building and read 46 volts.
 
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