First post: thanks in advance for any suggestions. I've enjoyed reading some of the threads here.
I was called out last week to check out a pulsing light situation. The HO's lights were pulsing about every second and a half with a brighter flash.
I checked the voltage at several receptacles, and found some to be around 80V and some to be about 150V. As I went down to check the connections in the load center, two lights in the basement began alternately dimming and brightening, all by themselves. Never saw anything like it.
The load center is a split buss Sqaure D with a 60 amp breaker feeding the lower legs. The house had been vacant for a couple of years, and the HO had the power turned on last week, and is in the process of moving in. She's been running the fridge for about 4 days and the vacuum, etc.
The lugs were tight, including the neutral. The only odd thing I saw in there was that the copper neutral was extended with another wire and a bug connector. It seemed to have no-ox on the connector and wires where they joined. I inspected and tightened up that connection.
L1 read about 80V and L2 about 150 right at the lugs. I turned off the breakers and decided to check the voltage at the weatherhead. It was 124 at both legs. Went back downstairs and realized that it was 124 now at both legs at the lugs with the breaker off. So I turned off all the breakers except the one feeding the lower legs, and all individual breakers on the lower part and turned them on one by one. I could only turn on 3 of the 7 breakers without the voltage going wacky. One of them that caused the voltage change was a dedicated outlet right at the load center with a light plugged into it. I checked the wiring in that outlet and tried it again. Same result. The light glowed dimly, and the legs went from equal to unequal. Seemed like whenever there was a load at all, it would shift the voltages to unequal. I'm thinking that the 3 breakers I could turn on without the anomaly must have been free from a load. With the wire of the dedicated outlet disconnected, all I would have to do was touch either leg with the wire, and again the light would glow dim and the voltage go unequal on the two legs.
I then checked outlets upstairs to see which were energized with the 3 breakers, and they read 124V. But when I plugged a light into them, it glowed dimly (and no doubt the voltage on the busses went unequal again).
I'm now reading about 5V on one side and 250 on the other side if I turn the breakers on.
I'd really like to fix this for the HO if I can.
It seems to be a bad neutral, and I suspect it's between the transformer and the load center. The transformer is maybe 150 feet from the weatherhead. I'll be calling the POCO tomorrow and will have them check their end, but my experience is that their contractors sometimes do not care enough (or know enough!) to check out their end properly. Should I ask them to perform any specific tests (like load test) or what?
On the other hand, I'd like to be as thorough on my end as I should be, before I call them. (I care enough, but I may not know enough!) Any suggestions? (I did not pull the meter, by the way... I guess it could be connections in there, as well.)
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by way of introduction, since this is my first post, I'm a general contractor in Pennsylvania. I have done whole house rewires and installed new services in the past, but I generally do building projects now, though I often do my own wiring on those projects.
I was called out last week to check out a pulsing light situation. The HO's lights were pulsing about every second and a half with a brighter flash.
I checked the voltage at several receptacles, and found some to be around 80V and some to be about 150V. As I went down to check the connections in the load center, two lights in the basement began alternately dimming and brightening, all by themselves. Never saw anything like it.
The load center is a split buss Sqaure D with a 60 amp breaker feeding the lower legs. The house had been vacant for a couple of years, and the HO had the power turned on last week, and is in the process of moving in. She's been running the fridge for about 4 days and the vacuum, etc.
The lugs were tight, including the neutral. The only odd thing I saw in there was that the copper neutral was extended with another wire and a bug connector. It seemed to have no-ox on the connector and wires where they joined. I inspected and tightened up that connection.
L1 read about 80V and L2 about 150 right at the lugs. I turned off the breakers and decided to check the voltage at the weatherhead. It was 124 at both legs. Went back downstairs and realized that it was 124 now at both legs at the lugs with the breaker off. So I turned off all the breakers except the one feeding the lower legs, and all individual breakers on the lower part and turned them on one by one. I could only turn on 3 of the 7 breakers without the voltage going wacky. One of them that caused the voltage change was a dedicated outlet right at the load center with a light plugged into it. I checked the wiring in that outlet and tried it again. Same result. The light glowed dimly, and the legs went from equal to unequal. Seemed like whenever there was a load at all, it would shift the voltages to unequal. I'm thinking that the 3 breakers I could turn on without the anomaly must have been free from a load. With the wire of the dedicated outlet disconnected, all I would have to do was touch either leg with the wire, and again the light would glow dim and the voltage go unequal on the two legs.
I then checked outlets upstairs to see which were energized with the 3 breakers, and they read 124V. But when I plugged a light into them, it glowed dimly (and no doubt the voltage on the busses went unequal again).
I'm now reading about 5V on one side and 250 on the other side if I turn the breakers on.
I'd really like to fix this for the HO if I can.
It seems to be a bad neutral, and I suspect it's between the transformer and the load center. The transformer is maybe 150 feet from the weatherhead. I'll be calling the POCO tomorrow and will have them check their end, but my experience is that their contractors sometimes do not care enough (or know enough!) to check out their end properly. Should I ask them to perform any specific tests (like load test) or what?
On the other hand, I'd like to be as thorough on my end as I should be, before I call them. (I care enough, but I may not know enough!) Any suggestions? (I did not pull the meter, by the way... I guess it could be connections in there, as well.)
----------
by way of introduction, since this is my first post, I'm a general contractor in Pennsylvania. I have done whole house rewires and installed new services in the past, but I generally do building projects now, though I often do my own wiring on those projects.
