Water cooled cable

[9408]

In a modern electric arc furnace, water cooled cable is used to conduct the electricity for the transformer to the furnace. What are the normal maintainance require for the cable. What are the signs to look for when the cable are due for replacement. What is the normal life of this cable.

 

[DougMSOE]

The biggest issue with this application is the conductivity of the cooling water. It should be very low, e.g. <10 micro-siemens.
Life of this cable is usually long 10+ years or more.
Leaks, fraying of the jacket etc. should all be watched for.
But conductivity is the big problem.

 

[gordonl]

We have had an arc furnace in service for about two years and haven't had any problems yet with the cables.

We perform periodic IR inspections to ensure we have good connections at both ends of the cable. (as well as the rest of the high current system) We also retourqued connections a while after installation but found few problems. I would say the thing to watch out for is mechanical wear of the cables due to flexing with furnace movement, as well as wear from bouncing around during unstable arc operation at the beginning of heats. (Evidenced as previously stated by outer damage and leaking)

I'm curious to hear why conductivity of the water is so important. I've had little concern for the conductivity of the water, other than to ensure each phase is balanced to ground.