What methods do you use for corona suppression when testing cable?

[madMAX]

This may be going overboard but for the test end I like to tape my lead to the conductor with some rubber splicing tape, wrap that with 33, and wrap all of that with plastic wrap. Opposite ends will usually just get plastic wrap and a PVC boot (made from piece of 18" PVC pipe and cap). With this method I get no hissing even with high humidity. Anyone have similar methods to suppress corona when testing cable?

[randywright]

Splice tape is usually good enough unless you are testing at crazy high voltages. Rubber safety blankets are also very useful when testing cable.

[AlexV86]

depending on test set our VLF/TD units minus the TD28 have corona Balls otherwise its wrap the lug tightly in the thicker Danger Tape and a little electrical tape to hold it in place then toss a rubber insulating boot over that does a good job but is not perfect, also less expensive then using splicing tape.

[madMAX]

Corona Balls? Sounds like you got that fancy stuff, Alex. My company only provides the bare essentials. Using rubber boots and blankets seems like a good idea except large blankets can be a pain to work with. Maybe I can rob some boots if I come across some on a job. The insulating plastic I have is only good for 8kV I think.

[alexlounsbury]

During VLF testing, I haven't found a need to cover the cables. The theory behind the practice is just to limit the amount of air moving across the cables.

For DC HiPot, keep in mind it's a pass/fail test. I used to work hard for high quality corona supression, but even a high reading shouldn't be used for trending. If it holds the voltage, it passes. Leakage currents will vary widely with humidity and wind, regardless of the supression method. Also worth noting that any direct contact that the insulation method makes will create a point for leakage current.

In a pinch several years ago, I used latex gloves. They worked great, though I wouldn't recommend them as a general practice.

[Chipperk]

This may be going overboard but for the test end I like to tape my lead to the conductor with some rubber splicing tape, wrap that with 33, and wrap all of that with plastic wrap. Opposite ends will usually just get plastic wrap and a PVC boot (made from piece of 18" PVC pipe and cap). With this method I get no hissing even with high humidity. Anyone have similar methods to suppress corona when testing cable?

I use elastimold fixtures on load break and dead break elbows look on eBay. Zero corona! They are not cheap but makes your job so much easier in high humidity areas with allot of wind and such. I also use the splicing tape on air connections.

[chils15]

Man scotch 33 bet the boss didn't put that in his price. Just use the danger tape works good

[copes2680]

130C tape and a good boot and your good to go. Unless you have corona balls

[whiskers]

This may be going overboard but for the test end I like to tape my lead to the conductor with some rubber splicing tape, wrap that with 33, and wrap all of that with plastic wrap. Opposite ends will usually just get plastic wrap and a PVC boot (made from piece of 18" PVC pipe and cap). With this method I get no hissing even with high humidity. Anyone have similar methods to suppress corona when testing cable?

What works for me are corona balls. Not the expensive ones. Just go to a craft store and buy a bunch of those Styrofoam balls of different sizes and bring along a roll of aluminum foil.

Wrap the ball in the foil and just jam it on the end of the cable. Works every time.

[SecondGen]

What works for me are corona balls. Not the expensive ones. Just go to a craft store and buy a bunch of those Styrofoam balls of different sizes and bring along a roll of aluminum foil.

Wrap the ball in the foil and just jam it on the end of the cable. Works every time.

Great tip, I will be trying this next time I test cable.