Alternating Voltage ?

Status
Not open for further replies.
e57 said:
Hope you understand what I'm trying to say - you might look a little silly if after replacing the AL there is still a problem -
Click to expand...
I agree. It sounds like the OP is guessing at this point, which is a shame. I'd venture to say that 9 times out of 10 that I encounter problem that is neutral related, it's the POCO's problem. That's not to say that I don't end up having to troubleshoot their end anyhow to find it, but it's almost always a POCO problem Bad taps at the weatherhead, bad taps at the pole mount transformer, tree rubbed through aerial cable neutral, aerial neutral having a "missing section" for unclear reasons, underground cable having rotted out neutral, bad tap at padmount transformer flags, and a partly blown up primary to secondary netural jumper internal to the pole mount transformer are among the main reasons.

You can have an aerial tap that will visually look fine when you remove the cover. When you measure voltage on one conductor on one side if the tap, it'll be good. When you measure voltage on the other conductor on the other side of the tap, it'll be off. If you wrangle the tap around a bit, you can sometimes hear the tell-tale "sizzle" and maybe even get a few sparkles out of it.
 
Open neutral

Open neutral

This is a classic open neutral. I only have a few moments and can explain later. From the info given it is probably a bad poco line /xformer ground that was a problem for years and was finding its path only through the neigbors service and when the new service was installed it somehow lost what little grounding capability it had. The condition will only show itself under an imbalanced load call poco and insist there is a life threatening situation and they will send a truck out and fix it. Just be sure the problem is not inside the house and only use resistive loads no electronics or motor loads.
 
e57 i do understand what you are saying, and i appreciate your feedback and advice as well as everyone else.

i am guessing at this point, as to the cause of this problem. i've only got an an hour into this job cleaning up the p.o.a. and visually inspecting panel and meter .when i go back on tues. morning i will incorperate the troublshooting tips you all sugested. i'll post what i find. thanks, mark
 
I'll chime in, and give my $.02 - open nuetral.:grin:

Usually, I find it is on the POCO side, but not always. I had one a few years back, in a new house. The lights were all flickering, and I was sent to check it. Found all of the 120v on one side of the panel, all 240v on the other, so all of the branch circuit nuetrals were on the same bar. Turns out the factory screw securing the bar was loose, causing the flickering. I might have missed it, if not for a sharp-eyed helper, who noticed a little spark at the screw when the lights flickered.
 
In the mid-90's, I ran into quite a few Square D panels that has a loose screw on the big lug that secured the service neutral to the bar. You had to remove the lug screw and the neutral conductor to get to the Torx drive screw that secured the lug to the bar. What a pain. I think it was a T-20 Torx drive, if I'm not mistaken. Still to this day, I continue to make sure that particular screw is tight on my new Square D installs. That problem seemed to be isolated to the mid-90's.
 
I just finished up at job, took e57 methood of using 500w quartz light, gfi spiltter and 25' extension cord with large alligator clips, which are crimped on to black, and white wires. Tested se cable at panel, then at line side lugs on meter pan, problem still persists, cut utility feeder at p.o.a. hook up tester on utility side no problem.I would have bet on it that this was a poco problem had someone offered. Replaced old se with new cu. se and things are back to normal. I did keep the old cable, when i have time i'll open it up, i'm still curious as to where in the cable the fault occured, upon visual inspection cable looks fine. Thanks again to all who responded.
 
e57 said:
Not that having a fault in a cable is odd, but it feels better knowing thats where it was, doesn't?
Click to expand...
Don't be so sure. He said something very important that pretty much invalidates his whole troubleshooting procedure. He said:

...cut utility feeder at p.o.a. hook up tester on utility side no problem.
Click to expand...

If he would have simply connected to a little bare spot on end end of the triplex, on the line side of the taps, that would have been a more valid test of a possible bad SE cable riser. The only thing cutting it, then doing the test proves it that it could have been bad taps or it could have been a bad SE cable riser. I frequently have found taps that look completely fine on visual examination, but a test on both the line and load sides, or an FOP test of the tap reveals that it is bad. I am willing to offer that I have found sections of SE cable with the neutral rotted off inside, but due to the testing procedure used, we'll never know if the SE was bad or the taps were bad.

Glad it's sorted out, in any event.
 
Last edited:
Status
Not open for further replies.
Top