# Proximity Testers and Flash Tape



## Lone Crapshooter (Nov 8, 2008)

Our distribution systems are underground and our 2400 volt is unshielded and when it passes through a pit it is flashed wraped with Scotch 77 tape. 
Today we were trying to identify some 2400 volt wiring for a project when we noticed that the Tic Tracer was not reliable at detecting energized cables under the flash wrap . 
We check the Tic Tracer each time we use it by procedure with a piezo tester and it checks fine. I have looked at the 3M site and they do not mention any cautions about checking voltage through the flash wrap. 
The cables are in bundles of 2 or 3 and I am wondering if there is some kind of field canceling effect with this arrangement?
Has anyone else noticed this and is there any ideas why this is happening ?
We noticed with 2 Tic Tracers.

Thanks LC


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## Big John (May 23, 2010)

Bundling opposing phases absolutely will cancel electric fields, but if you're right on the conductor, I would still expect the tic-tracer to read. The only other thing I can think is if the tape absorbs moisture, I could see it significantly dampening the field, but I've never used 77.

-John


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## Wirenuting (Sep 12, 2010)

Our tiny tic tracers never worked on our 4160. We used the ones from Salisbury instead.


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## millelec (Nov 20, 2010)

there's usually a warning either on the tic or its case to use caution if using on 3 phase power supplies, as the fields do cancel each other out. I like to pull the wires away from each other if testing 3 phase for voltage using a non-contact tester. Since your cables are wrapped, doesn't sound like an easy option.


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## Lone Crapshooter (Nov 8, 2008)

We use a "Tic Tracer" and it is rated from 120 to maybe 35KV plus we have a Salisbury orange mushroom to check the 138KV in the switch yard.
As far as pulling a wire out of the bundle it takes 2 hours minimum to get in the pits. 
What we were doing today is reaching down into the pits with Tic Tracer on a hot stick.


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