parallel feeds using MC

Status
Not open for further replies.

nakulak

Senior Member
I want to run some parallel feeds using MC. I've always done it in conduit before, but in this particular application MC is definitely the way to go (several 400A panels 208/y120 -hotel 2nd, 3rd 4th floor riser panels). Any issues with this installation that I'm overlooking ?
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
As Tim said you'll need an EGC in each parallel cable based on the size of the OCPD protecting the feeder. You might end up needing cables with a full size EGC in each one.
 

iwire

Moderator
Staff member
Location
Massachusetts
If you have the pulling equipment maybe go single runs. Of course easy to say from here without seeing what kind of route you have to go.
 

horsegoer

Senior Member
Location
NJ
Occupation
Estimator
What is a parallel run?????? I heard of wire being ordered paralled before....

thanks.
 

nakulak

Senior Member
What is a parallel run?????? I heard of wire being ordered paralled before....

thanks.

sometimes its cheaper (for a variety of reasons) to install some sets of conductors in lieu of (whatever the correctly sized set of 1 set is). its called parallel sets. (310.4, 250.122 F)
 
Last edited:

mcclary's electrical

Senior Member
Location
VA
Okay, just for fun, let's look at it from the other side: If you were an inspector, what would you accept as proof?

If I could lay my eyes on it for it's entire run, and if it had the correct size ground, I would pass it. But if they disappeared for a long run through an attic or something, at that point, you cannot prove they are of equal length, as you could with conduits.
 

iwire

Moderator
Staff member
Location
Massachusetts
If I could lay my eyes on it for it's entire run, and if it had the correct size ground, I would pass it. But if they disappeared for a long run through an attic or something, at that point, you cannot prove they are of equal length, as you could with conduits.

When a conduit runs out of sight how would you know how it was run?

It's called a rough inspection here.:)
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
If I could lay my eyes on it for it's entire run, and if it had the correct size ground, I would pass it. But if they disappeared for a long run through an attic or something, at that point, you cannot prove they are of equal length, as you could with conduits.
Sure you could...you could use a TDR or short two conductors of each set together at one end and use a micro-ohm meter at the other end and compare the resistance. In most cases, you can have a 5 to 10% difference in the conductor lengths without overloading the shortest set of conductors.
 

wawireguy

Senior Member
Is there a exception for grounds included in cable assemblies somewhere? I foggily recall something about neutrals or grounds that could be undersized if they were in a cable assembly. I could be way off on that one..
 
Status
Not open for further replies.
Top