Energized cables, no -load on
Energized cables, no -load on
(OP)
Hello,
I'm trying to refresh my memory, Years ago, I had heard that it is not good for the life of cables to keep them energized with no load on them. Specifically, I'm thinking of a loop system where the loop is open at one switch and the cable is energized from the other side to the bottom of the open switch.
I don't remember the exact reasoning but seem to remember something along the lines of the fields and cables not being able to kept dry from the heat of current passing through.
Does anybody have any comments on this?
Thank You
I'm trying to refresh my memory, Years ago, I had heard that it is not good for the life of cables to keep them energized with no load on them. Specifically, I'm thinking of a loop system where the loop is open at one switch and the cable is energized from the other side to the bottom of the open switch.
I don't remember the exact reasoning but seem to remember something along the lines of the fields and cables not being able to kept dry from the heat of current passing through.
Does anybody have any comments on this?
Thank You






RE: Energized cables, no -load on
...
My friend Norman was the project manager for a flight simulator, just entering its installation phase. One fine day Norman entered a room at the customer's facility, noticed an unterminated cable lying on the floor, said "What's this?", and before anyone could answer, picked it up.
Did I mention that the cable was as thick as your arm?
Did I mention that the conductors had been stripped?
Did I mention that the cable was live?
The resulting short lit up the room, then darkened it, taking out a 1200A service and shutting down part of a military base for a while.
Norman was, ahem, cautioned, about picking up stuff without permission after that.
Mike Halloran
Pembroke Pines, FL, USA
RE: Energized cables, no -load on
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RE: Energized cables, no -load on
In rare conditions, this overvoltage may be above 10% of nominal system voltage, with possibility to exceed the cable insulation rating or creating overstresses to power system components.
RE: Energized cables, no -load on
RE: Energized cables, no -load on
RE: Energized cables, no -load on
RE: Energized cables, no -load on
Benjamin Lanz
Vice Chair of IEEE 400
Sr. Application Engineer
IMCORP- Power Cable Reliability Consultants
RE: Energized cables, no -load on
Thank You
RE: Energized cables, no -load on
RE: Energized cables, no -load on
I think that I will start a new thread on this.
Gunnar Englund
www.gke.org
RE: Energized cables, no -load on
I am sorry it took me so long to reply. I am just returning from the IEEE Insulated Conductors Committee conference.
The issue is not a simple one. If you leave a cable energized (with or without a load) you are likely to have a normal distribution of failures over time (if any). If you deenergize the cable you are likely to have most of the failure (if any) soon after energizing. Explaining these statements from a material stand point would be near dissertation length. I recommend that you keep the circuit energized and document the history of the cable as it ages with the rest of the population. When you need the cable again you will have some idea of what level of reliability to expect.
Benjamin Lanz
Vice Chair of IEEE 400
Sr. Application Engineer
IMCORP- Power Cable Reliability Consultants
RE: Energized cables, no -load on
Thank you for the reply. This puts the issue to bed for me.
Barry
RE: Energized cables, no -load on
A de-energized cable laying in the ground is an unknown quantity and at minimum would require a hi-pot or meggar test prior to energization. If the cable has exposed ends it could absorb moisture.
On the other hand, having unneccessary cables plugged into a distribution system can cause unneccessary outages.
RE: Energized cables, no -load on