What Type of Cable is This

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charlie b

charlie b

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Semi-Retired Electrical Engineer
I was at a project site yesterday. The superintendent showed me this. He wondered if code allowed this type of cable to be run outdoors and to be run underground. I could not read the label, and the photo is not all that good. Can anyone identify it for me? TIA.

 

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Is that a "BX" style flexible cable? And is the top part in shadow, or is that some kind of coating?
 
The top part was in shadow. Below is a view from the opposite side, and a bit further back. The enclosure is about 3 feet off the edge of a dirt / gravel roadway, and there is a traffic barrier closer to the roadway. About 20 feet further from the road than this enclosure, there is a drop of a couple hundred feet. This cable is run underground for part of the way down the hill, and sits on top of the dirt and rocks the rest of the way down. It is a feeder to a small building that houses a motor-driven gate valve that is used to control river flow. Did I mention this was at a dam?

 

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charlie b said:
This cable ... sits on top of the dirt and rocks the rest of the way down.
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This seems like a big problem. The PVC jacket on that is not very thick and can easily be damaged. I'd also be concerned about the cable being crushed.
charlie b said:
It is a feeder to a small building that houses a motor-driven gate valve that is used to control river flow. Did I mention this was at a dam?
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What are the consequences if this valve fails to operate?

 
The cable that sits above ground towards the bottom of the hill cannot be touched by any vehicle, forklift, pedestrian, or industrial machine. It is safe in the sense that nothing external can damage it. The hill is very steep. If this feeder is lost, the site will not be able to use a motor to change the position of the valve. There is a manual hand wheel, however, and they might want to change the valve position a couple times a year. Not a big operational concern.
 
OK. My post #6 gives a reasonable basis for believing that the cables are not "really" subject to damage. But now I am starting to think that that does not matter. My reading of 300.5(D)(1) tells me that additional protection is called for. At the bottom of the hill, the cables are once again run underground, this time under a roadway (more like a gravel parking area). On the other side of this area, they come up from the ground and into a disconnect switch for the building power. There is no raceway protection there either.

Since my role in this project is to perform a "condition assessment," I am going to cite this as an issue.

Many thanks for the information.
 
I agree with citing this as an issue. External damage doesn't have to come from human activity. An animal can chew on the PVC covering, compromising its watertightness. Even a loose rock rolling down the steep hill can damage the cable.
 
The appearance is exacly that of MC-HL, corrogated, continuous sheath
Several manufactruers, General, USA, Okonite (CL-Xx).

For the north, for under-ground transitions areas, it is godsend. It does not buckle and tear the boxes apart like rigid will.

Works extremely well for underground. The plastic sheath protects from most of the stuff in 330.12. Conduit breaks at the joints (couplings) and rusts, yes, even galvanized. No, it does not fill up with water.

End fittings are TMC or TMCX. TMCX are potted and used in classified areas. Suitable for CI, CII, CIII, Div 1, Div 2.

NEC requires protection. In areas of vehicle trafic, I'll use a couple of bollards to keep the trucks from parking on it. Not much diffrerent thaqn one would use for protecting rigid in a process area.

I like it, use it in lieu of rigid any time possible.

the worm
 
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Jon456 said:
I agree with citing this as an issue. External damage doesn't have to come from human activity. An animal can chew on the PVC covering, compromising its watertightness. Even a loose rock rolling down the steep hill can damage the cable.
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The ground squirels, marmots, other furry things with teeth will chew up the PVC sheath. The aluminum armor stops the water tight compromise.
 
iceworm said:
No, it does not fill up with water.
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Every conduit that goes underground eventually accumulates water from a combination of "breathing" and condensation of water vapor from the air. Unless the conduit is purged with a gas like dry nitrogen and sealed airtight at both ends.
 
Jon456 said:
Every conduit that goes underground eventually accumulates water from a combination of "breathing" and condensation of water vapor from the air. Unless the conduit is purged with a gas like dry nitrogen and sealed airtight at both ends.
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Right you are - if it were conduit
 
charlie b said:
.... My reading of 300.5(D)(1) tells me that additional protection is called for. At the bottom of the hill, the cables are once again run underground, this time under a roadway (more like a gravel parking area). On the other side of this area, they come up from the ground and into a disconnect switch for the building power. There is no raceway protection there either. ....
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Yes, 300.5.D.1 does say that. Our spec doesn't call for any metalic/conduit sheath up to 8 feet. And I have not had any of the AHJ squawking. However, all my work in industrial areas, generally in process limits.

Our protection issues are generally keeping the snow plows off when they are scrapping the parking areas right next to the equipment - plastic covered steel pipe and concrete bollards work well
 
iceworm said:
Good choice but likely not. The linked southwire is interlocked armor.

Charlie's example looks more like continuous, corrogated, welded sheath, MC-HL
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Well you must have better eyes than most of us to be able to see that the cable is different that what I linked to.
 
As the "grandfather" of MC-HL, I concur with iceworm. I would confirm that it is indeed MC-HL (hard to read the label) although it looks like it.
 
rbalex said:
As the "grandfather" of MC-HL, I concur with iceworm. I would confirm that it is indeed MC-HL (hard to read the label) although it looks like it.
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You're saying you were in the development if MC-HL?

If that is what you are saying - bless you.

So, tell us a story.

Considering I have 30 years in fighting conduit, followed by 20 years of MC-HL, I ready to shake hands and buy you a beer. I'd even share my good Scotch.

worm
 
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