HL MC cabling

[Rockyd]

Power Quality question...

We have a bunch of HC-MC cables dumping into large cabinets (6' x 3' x 2') that are control cables (triad, shielded). The cables are mostly long runs - 200' to 750' in ladder cable tray. We have the cables entering into the cabinets via TMC connectors (or TMCX depending on environment), and dumping into Panduit ducts for cable routing to termination strips (DIN rails).

In stripping the cables, am I better off to leave the mylar/tinfoil shield on till coming out of the panduit to actual landing,(thus only the ground wire would be left to drop down to it's ground bar) or strip the cable back all the way to the fitting, and run my ground drains off to their respective ground bus?

The cabinets are 24 VDC so can't imagine where there would be that much "noise" in the cabinet to be induced onto other wires. Not being an engineer though, I'm asking for clarity. Thanks in advance.

 

[HighWirey]

What does your spec say? Maybe you are not working to a spec.

In my orbit every owners spec was the same - enter the cabinet through the appropriate gland/entrance fitting, immediately remove the neoprene/PVC/whatever jacket, splice to an insulated '*drain' wire, then on to your termination point with the insulated 'drain' wire. 'Drain' wire size varied from 16awg to 10awg.

*or whatever you want to call it !

Regardless of cable outer diameter, we usually had to use those durn burn Burndy Hyrings for the 'splice' at the cable butt point.

Except for the hyrings, my advise is probably good for most installs. And always treat the 'drain as a current carrying conductor.

Merry Christmas Everyone and Best Wishes

 

[Rockyd]

Job bid specs didn't have this detail, one of those "assumed " items. I've always stripped back to the fitting using the zip string in the sheath, heat shrunk the "booty" on the end of the cable, and heat shrunk the drains and landed them, tagged each conductor and landed on the strip.

Believe it's all class II, and class III, so don't see where it would be anything different, than what details 725.55 or 56 covers. I even have divider for the duct! cool stuff to qualify the 1/4" separation required to separate class I from the II and III 725.55(D). That I have divider required to be installed sets off a red flag in my head that there maybe other "things" scheduled for the cabinet that I'm not aware of yet!

Just curious if anyone was doing it different that what I'm used to. Always game to look at a way to improve.

 

[HighWirey]

Looked up the Appleton gland fitting for HC-MC. Similar to the ones we used.
My last code book is 1999, doesn't have 725.55 . That section seems to deal with separation of systems. I've only had to use dividers a few times.

"there maybe other "things" scheduled for the cabinet that I'm not aware of yet!"
Yes, we worked to that 'not aware of' syndrome most of the time.

"Just curious if anyone was doing it different that what I'm used to"
Your install plan sounds great, especially if you have those nice shrink boots. We used plain old shrink, did not look so good, but 'form follows function'.

Merry Christmas Everyone and Best Wishes