330.30(C) - MC Cable Securing/Supporting

[electricalist]

Cody i want to agree with you 100 % ..In resi it seemed like interval securing was strictly inforced ..then i came to commercial and saw exactly what you re talking about ,,,,one crew,,,,were strapping every place we can and believe we should another crew is running through the red iron like theres no inspection.
They passed and we spent 2x as much time and material ....now i do my job and if it fails i ask how would you like it fixed....and move on,,

 

[PetrosA]

Or you can buy the kind that pulls equally well in both directions.

 

[ActionDave]

Buying the MC cable reverse wound helps with cable hanging up when pulled through metal studs

I agree that having the correct end of the MC in your hand makes pulling easier.....I did not know you could buy it with the sheathe wound one direction or the other.

 

[david]

1,000 ft. rolls we ordered it reverse wound all the time. Everybody around here does.

Now around here that seems to be the way it is shipped even when it not ordered that way

 

[david]

Cody i want to agree with you 100 % ..In resi it seemed like interval securing was strictly inforced ..then i came to commercial and saw exactly what you re talking about ,,,,one crew,,,,were strapping every place we can and believe we should another crew is running through the red iron like theres no inspection.
They passed and we spent 2x as much time and material ....now i do my job and if it fails i ask how would you like it fixed....and move on,,

We always secured MC cable to the Bar joist as well. A piece of metal tie wire. Fold the tie wire in half loop the bar joist, then over the MC cable. Two free ends split the bar joist twist the free ends and move on.

Actually we would double up the tie wire (fold it twice) that helped with the twisted end not breaking when you tightened up the twist

 

[david]

I agree that having the correct end of the MC in your hand makes pulling easier.....I did not know you could buy it with the sheathe wound one direction or the other.

Its not the way the sheath is wound on the cable.

When the cable is spooled it comes off the spool the heavy end of the sheath catching during installation. You can have it re-spooled so the heavy end of the sheath is on the back end of the pull during installation.

 

[PetrosA]

Here's an illustration to help those who are having a hard time envisioning the problem. The top style of jacket is the one we're talking about and it only pulls in one direction without snagging on objects. It has to do with the squared off shape of the jacket and the fact that the squared off part is where the wind overlaps. When you pull against it, all it takes is a tiny bit of resistance and the jacket comes apart. Doesn't matter whether it's steel or aluminum. If it's started on the reel or coiled the wrong way, you can't pull it properly. I hate this kind of MC but it's the most commonly sold type.

The bottom style of jacket is rounded and is more like traditional BX. It can be pulled in both directions easily and rarely comes apart.