11 kV D.D.O. fuse explodes on a cable fault

The HV cable was meggered and had one phase reading lower than the other two phases, although the 5 kV Megger didn't break it down fully.

A low amperage high tension fuse was used to test the cable and avoid risking tripping the feeder.

The fault developed as a phase to screen fault which was later traced and thumped. Fault found in the crutch of the PILCpart of cable in the.300 kVA transformer.

Category:

Science & Technology

Tags:

• ddo
• cable
• fault
• explode
• explosion
• Dominion
• Drop
• Out
• fuse
• rewireable
• high
• tension
• 11000
• Volts
• network
• ontploffing
• power
• electricity
• Megger
• PILC
• XLPE
• expulsion

[NekoMasterMax]

Does it ever annoy you guys when the fuses keep blowing especially when you have to keep moving things up and down with the poles? I know just fixing computers when they fail repeatedly annoys me.

[RODALCO2007]

@NekoMasterMax It is part of the job, annoying when it rains but fuses are there for a reason.

[ChumpusRex]

Interesting. Does your megger only go up to 5 kV, or do you ever test at higher voltage?

I'm only used to meggering stuff at LV, where the test voltage is higher than line. I'd have expected the same sort of thing at HV. Guess I was wrong!

[RODALCO2007]

@ChumpusRex 5 kV is the industry standard. i used an AVO BM 25 Megger

With HV a polarisation index is done, and on feeders a VLF test applied.

DC is not good for XLPE cables.

[avoed1973]

wow it just shows what power there is

[robotwarsaintdead]

YOUR SUCH A TEASE

[ElectroMecca]

LOL, I put the phone down just before this hit like I was afraid I'd get shocked :-D

[pixitha]

Hope he was wearing ear plugs....ouch.

[DragonFlyback256]

@daewooparts

Doing it with -very- long fishing line and wire can be -relatively- safe (as long as the fishing line is new, dry and clean), but -never- advisable. It still is extremely dangerous and illegal.

[DragonFlyback256]

@HDXFH

There was an arc flash inside the fuse. They often contain solid Boric acid inside that generates a large volume of gas to quench the arc.