This post needs a clever title

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petersonra

petersonra

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Location
Northern illinois
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Semi-retired engineer
Something that happened at a job site I was at this week.

Feeder pull of (12) 500MCM conductors in 3 conduits.

400 feet.

Seven of the conductors failed megger test.

Part underground in PVC, and part above ground in conduit.

$70k worth of wire.
 
How about " why we fired the lead electrician" for a title.
That sucks, did the 500 mcm get tested before they were pulled ?
 
zog said:
How about "Good thing we meggered it"
Click to expand...
They bought a megger after turning on a feeder installed a few weeks early that welded itself to the inside of a conduit. I was told it was quite spectacular.
 
petersonra said:
Something that happened at a job site I was at this week.

Feeder pull of (12) 500MCM conductors in 3 conduits.400 feet.

Seven of the conductors failed megger test.

Part underground in PVC, and part above ground in conduit.

$70k worth of wire.
Click to expand...

Was it all three conduits had a bad one or more? Or did you guys at least get one clear conduit.
P.S. If you let me keep the scrap I'll come pull out the bad cable for free :grin: :grin: :grin:
 
Could be that gravel in the U/G ones.... Or the un-filed edges... Or the general lack of lube... But "Good thing we meggered it" fits pretty good...
 
acrwc10 said:
Was it all three conduits had a bad one or more? Or did you guys at least get one clear conduit.
Click to expand...
I am not sure where the problems were. I left the site yesterday. They had cut into the 3 conduits and found several of the problems and cut out the bad sections and spliced them back together inside a jbox. I am told they expect to have it fixed by tomorrow.
 
Why would they even be allowed to fix the bad sections?

Meggers are nice but they do not find everything.

We megged a motor and conductors at the load side of a starter to test the whole circuit. Checked good. Obvious smoke & tracks at the motor j-box said different. The fault had blown itself away from the fitting leaving enough of the conductor to run the motor. Just not enough tracking for the 1000v setting to find the fault. We had no previous test history for this motor which may or may not have helped.
 
Magnetoencephalography (MEG), also known as Magnetic Source Imaging (MSI) provides an image of the brain by recording magnetic fields over the surface of the head.
 
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