Magnetic flux create by cable

[cuky2000]

What should be a reasonable magnetic clearance from steel support assuming that there is a cable passing through a steel closed loop.
This example is typical for cable termination for HV cable installation that usually is installed with an open loop in the steel. However, we did not find a reasonable explanation why to use an open loop in the steel.

 

[waross]

Hello cuky;
The Canadian Electrical Code does not ban magnetic encirclement for currents below 200 Amps.
If your current will be above 200 Amps I would consider slotting the steel or using stainless steel or aluminum for the support plate..
I can't give you a dimension but anecdotally, I have seen severe heating with conductors passing through a hole larger than your whole plate.
Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[racookpe1978]

How many conductors in the cable, Just 1 conductor I think from the photo, right?
What current (AC or DC) in each conductor,
What is the equivilent "hole dia" in the support steel? Is it right up against the conductors, or much larger than the conductors? The diagram in the photo appears to show mag force levels as a distance from the conductor, not as a steel suport distance.

 

[ewo00]

A single conductor at 1000A, as shown on your figure, will generate a significant amount of heat. If you don't want to put an open loop in the steel, then consider stainless or aluminum like waross suggested.