Can you use 105deg C medium voltage cable on 480V circuits?
Can you use 105deg C medium voltage cable on 480V circuits?
(OP)
This is really a continuation of my other post asking about oversizing the motor leads beyond the NEC requirements to 250hp motor. I just want to look at all possiblilities. I checked but could not find any 600V cable that had an insulation rating of 105deg like medium voltage cable does...
There is nothing wrong with the 40 year old conductor now, the insulation of the cable is what has deteriorated. And that is the concern that that doesn't happen again.
The plant people still seem to think that oversizing the cable would be a good idea just because it would run cooler and like every thing else electrical prolong its life. If this is the concern, why not just get a higher rated insulation? I would think the higher insulation cost would be still much cheaper than increasing the amount of required copper by 50%.
There is nothing wrong with the 40 year old conductor now, the insulation of the cable is what has deteriorated. And that is the concern that that doesn't happen again.
The plant people still seem to think that oversizing the cable would be a good idea just because it would run cooler and like every thing else electrical prolong its life. If this is the concern, why not just get a higher rated insulation? I would think the higher insulation cost would be still much cheaper than increasing the amount of required copper by 50%.






RE: Can you use 105deg C medium voltage cable on 480V circuits?
The medium voltage cable has a larger minimum bending radius and needs more room for terminations, making installation more dificult.
A medium voltage cable will run hotter than the same size 600V cable due to the thicker insulation.
An inpsector may still require the cable be designed to a 75 C rating for the terminations.