Securing 4160 cables inside of MCC. 1

[EmergencyPowered]

Hey Experts,
I have been asked by a customer if this is kosher?
Where one may usually find more elaborate clamping and bracing of 4160v cable terminations, just past this a "METAL HOSE CLAMP" is used to group the cables on the internal routing to lugs. I see no obvious problem, everything is wrapped etc, but what about cable sheath damage possibilities. I don't exceed 1000v, meaning 480v as per company rules.
EVER SEEN HOSE CLAMPS USED?

 

[jraef]

I don't get it. Your thread title says 4160V, your posting says 480V. Which is it?

But either way, metal hose clamp... bad. Everything looks OK now, but have you ever watched cables during a fault, or even a large current surge like a large motor starting? There is a LOT of force exerted, a metal hose clamp could easily cut through the insulation and create a new fault. metal cable clamps have rounded edges so as to avoid that.

I believe also that it would be a Code violation. If nothing else, Article 100 under the definition of Identified:

Recognizable as suitable for the specific purpose, function, use, environment, application, and so forth, where described in a particular Code requirement.

So if you can show that it is INTENDED to be used as a cable clamp, OK. If not, not OK.

"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
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[LionelHutz]

The cable type isn't very clear in your description, but I would also be concerned with corona damage caused by using a metal hose clamp like a big tie wrap to hold unshielded and unjacketed 5kV cables together.

 

[wareagle]

I would not think a water hose clamp would be listed for this purpose.
Why not use a nylon strap?

 

[jraef]

I've even seen nylon cable clamps over tightened and cause a reduction in 5kV cable dielectric. On one project we could hear a ticking sound in the box from the outside but couldn't see anything when we killed power and looked around. So we turned off the lights, opened the door and energized the equipment. A little blue ghostly halo was formed around the nylon clamp, which fed into a spider web like flow of plasma along the cable surface until it found a place to discharge to ground. It looked alive, very creepy. We killed power, cut the clamp and did it again, problem went away. Don't ask me to explain it, I can't.

Don't ask me to EVER repeat that lunacy either. I had to pinky swear with my technician to never ever tell this story (sorry Hans if you're reading this and recognize it). We knew what we were doing was foolishly dangerous, but we were stuck in the middle of a miserable place and not allowed to leave until we solved the problem, we did NOT want to stay another day. We were very far away from the equipment when observing it, but still, I'm not unaware of how lucky we were to have come away with no scars.

"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
For the best use of Eng-Tips, please click here -> faq731-376

 

[EmergencyPowered]

I thought so, thanx. I never was a fan of this!