Feeder Cable Splice Near Swithgear

[hidalgoe]

Hi:

Recently a phase conductor on a 3-Ph, 480Vac system suffered some damage due to overtemp caused by a loose breaker terminal lug.

Rather than replace the feeder, we chose to temporarily splice a new conductor length to replace the damaged section that was cut off.

Some folks in my organization think that the splice should have been made futher down stream away from the switchgear and enclosed in an appropriate box.

Others feel that if a fault occurs due to splice failure the feeder will be protected by the breaker.

Comments please...

 

[weh3]

The splice will probably last longer than the rest of the conductor. Splices should be in an accessible location; i.e., you should make up the splice after pulling the cable instead of pulling the splice into a conduit.

William

 

[dpc]

The splice kit should have the same temperature rating as the insulation of the conductors being spliced, at least as high as the rating of the nearby breaker termination. As long as it is accessible, I don't see a big problem. In an ideal world, you would never splice a power circuit, but based on my little corner here at least, the world is far from ideal.

 

[PowerfulStuff]

Hi,
I like the idea of the splice away from the switchgear, particularly for high fault currents. That way if you have a fault at a known weak point (the splice) you don't risk the switchboard as well, and the fault current will be lower further away from the board.

I'm not sure about enclosing it. Any splices we have are included in thermoscanning for some piece of mind.

What kind of load and fault currents have you got?

Regards,
Martin

 

[JBinCA]

If a fault in the splice is protected by the breaker, it will be protected by that breaker no matter how far down the line the breaker is.

JMB