Megger question

[alaskan JW]

Is there a way to megger 350mcm xhhw wire while

it is still on the spool? Or some other method to

make sure that the wire has no insulation problem.

We are pulling in wire that the coast guard is

providing us and we are trying to figure a way to

test it before we pull it in. They have been storing

it in their warehouse.

 

[ron]

Is it a single conductor or multi conductor? It is essentially an ohm meter that measures through the insulation, so you need something to measure "to" like raceway or another conductor.

 

[cadpoint]

Well there might be a way to get a record of the lot number off the reel or the wire its self or trace it back from the little long funny number inprinted on the wire.
This number will give you a base-line number to use and compare it to.

For example: the company might manufacture and run 10K feet of that size AWG wire at one time but only test a 500 foot reel. Theres other check and balances in the manufacturing as to not stress or stain the copper as its bound together.

Since your up there in Snow Land, and it was for the USCG, I can't beleive that your reels weren't tested individually. But theres still the lot number that was imprinted, it is its preminent record.

Larger, odd wire manufactured especially with outer shielding were always tested. I us to test reels, speciality wire "w" rated where dunked in water tanks and tested after a 24 hour soak.

I can't totally recall the machine, but I do remember testing with high voltage and no load, both wet and dry, heres a link to that
http://books.google.com/books?id=V1SXEnhCN88C&pg=PA265&lpg=PA265&dq=voltage+testing+with+no+load&source=web&ots=KMOagH7Aqh&sig=E7gMi57FhvSyhbzR7_JuN5FO-30&hl=en&sa=X&oi=book_result&resnum=10&ct=result

I went over and looked at UL.com but that just went everywhere with the same phrase "voltage testing under no load" althought 2006 white book did come up alot.

 

[growler]

Is there a way to megger 350mcm xhhw wire while

it is still on the spool?

Yes, it is XHHW so if you could seal the end of the cable and then submerse it in a pool of water ( metal tank) then you could meg to the tank for insulation leakage.

If you think this is a joke ( it may be ) just start reading the Southwire web site on what they would have to do to certify a cable.

 

[alaskan JW]

Is it a single conductor or multi conductor? It is essentially an ohm meter that measures through the insulation, so you need something to measure "to" like raceway or another conductor.

IT is single conductor.

 

[ptonsparky]

I have taken old uf cable and submersed it in water than tested it. Only way I could think of doing it. Certainly a lot easier with what I had vs your 350.