beanland
Senior Member
- Location
- Vancouver, WA
Medium-voltage cable, single-conductors, can I clamp each phase with its own metal cable clamp without having to worry about current induced in the clamp?
If the clamp and what it is attached to is ferrous and will completely encircle a single conductor you will have heating in the clamp. If the current is high enough, the heat could damage the conductor insulation. If there is a gap or if the clamp is non-ferrous you won't have a problem.Medium-voltage cable, single-conductors, can I clamp each phase with its own metal cable clamp without having to worry about current induced in the clamp?
I don't think the shield makes any difference for this.Would an encircling metal clamp matter if the cables were shielded?
I don't think the shield makes any difference for this.
Normal conductive shielding will reduce the electrostatic field (making non-contact voltage sensors ineffective) but will not noticeably reduce the magnetic field outside the shield.I don't know either but I was thinking that the shielding may have some effect since it already encircles each conductor.
What you are indicating is what I have been otherwise informed. (did I say that?)
I know that if I have a ferrous (magnetic) clamp, I need to put an "air gap" in it to make sure there is no current flow.
What if I have a ferrous clamp, with a gap, but that gap is bridged by a stainless steel (non-magnetic but conductive) bolt.
What I am having a hard time accepting is that if I place a non-magnetic conductive loop about a single phase conductor there will be no current induced in the loop.
What you are indicating is what I have been otherwise informed. (did I say that?)
I know that if I have a ferrous (magnetic) clamp, I need to put an "air gap" in it to make sure there is no current flow.
What if I have a ferrous clamp, with a gap, but that gap is bridged by a stainless steel (non-magnetic but conductive) bolt.
What I am having a hard time accepting is that if I place a non-magnetic conductive loop about a single phase conductor there will be no current induced in the loop.
I know that if I have a ferrous (magnetic) clamp, I need to put an "air gap" in it to make sure there is no current flow.