"Tube Audio" wrote in message
...
Hello

I have an Industrial Installation of a string of about 20 SPST Emergency
Stop Switches in series, They are wired Normally Closed. 24VDC is
connected to the string and the switches will interrupt the 24V when
pressed in and Emergency.

The wire is 18 GA stranded and the total length of the string is about 800
feet.

The wire runs in conduit.

I believe I have an intermittent short to the conduit, usually the short
occurs just momentarily so troubleshooting is difficult.

I was thinking of Hi Potting the Switch String. I was going to disconnect
each end of the string and Hi Pot the cable run along with the installed E
Stop Switches. To verify if some part of the conductor is very close to
the conduit.

I believe the wire is rated at around 600V.

The question is what Voltage should I set the Hi Pot tester to and why.
The other end of the Hi Pot tester will connect to the conduit.

Thanks


What makes you think it is a short ?

800M is a long run at 24V. If the circuit is holding a contactor in, small
voltage fluctuations will drop it out.

George.