Using NM Cable Holder with Non NM Cable

Reply

  #1  
Old 12-26-12, 07:32 AM
Member
Thread Starter
Join Date: Jul 2009
Location: NYC
Posts: 302
Using NM Cable Holder with Non NM Cable

Just noticed this...
The licensed electrician that did my mini-split electrical about 3 year ago used a NM connector on the KO on the panel to hold the 1/2 Flex.

What is the effects, detriments of using such connecter and the material being held. I'm not looking forward to it but to correct it, I guess I will have the disconnect the 8 or 6 gauge they have to remove it off the panel to slip the correct connector on.
 

Last edited by pingable; 12-26-12 at 10:28 AM.
Sponsored Links
  #2  
Old 12-26-12, 07:34 AM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,968
No, it must be a flex connector with a bushing. The NM connector is not approved for use with flex. 8/6 cannot pass through a 1/2" flex, so there is some confusion there.
 
  #3  
Old 12-26-12, 07:49 AM
Member
Thread Starter
Join Date: Jul 2009
Location: NYC
Posts: 302
It's got a bushing. Not sure but I also see a hint of *paper* under where the flex is around the connector. Unless he used some sort of special wire that was wrapped in paper. It's 1/2 flex I think *OD measures around 8.7"*. 3 Wire for the 2 Hots and Neutral. That's all I know. I know it has to be at least 8 gauge cause it's on a 50 amp breaker. The wire in the panel if I recall looks much thicker though....
 
  #4  
Old 12-26-12, 08:45 AM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 32,646
Can you post a picture from the inside and outside of the panel so we can see both ends of the connector?
 
  #5  
Old 12-26-12, 09:01 AM
Member
Thread Starter
Join Date: Jul 2009
Location: NYC
Posts: 302
Indeed I have a pic. U can't see it from the angle I shot, but I do see a red bushing in there.

I may be wrong but I thought all NM connectors has the *screws* to both sides of the strap...



 
  #6  
Old 12-26-12, 09:44 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,357
Looks like a Greenfield connector to me. I don't know why the paper is there.
 
  #7  
Old 12-26-12, 02:08 PM
Member
Thread Starter
Join Date: Jul 2009
Location: NYC
Posts: 302
THX PCB. What's the telltale sign its for MCT ?

I'm no sparky but the only time I see that strap config is for NM cable...

I don't know why there is papere as well. I suspect he pulled the flex and then ran 8/3 BX inside it. I only guess that cause there is a bonding wire sticking out as well...I suppose the paper is the paper you normally see wrapped around the wire in AC/BX cable.
 
  #8  
Old 12-26-12, 03:31 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,968
See the angular indentation at an angle matching that of the flex? That as well as the manner in which it is attached to the box. The flex entering the side of the box is called 1/2" nominally, so remeasuring the flex may show it to be a little larger to accommodate the larger wires. IF the OD measures 8.7", then it isn't 1/2". Confusing.
 
  #9  
Old 12-26-12, 05:23 PM
Member
Thread Starter
Join Date: Jul 2009
Location: NYC
Posts: 302
Typo. I meant the OD of the flex was .875ish..

You learn something everyday. So that *slash* on the clamp was the telltale.
 
  #10  
Old 12-26-12, 06:27 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: Twin Cities, MN
Posts: 11,981
That is AC cable. You can tell from the small bonding strip and the brown paper. Aluminum clad AC is required use a clamping type fitting like the one shown. Setscrew type connectors are not acceptable. IMO the paper should have been removed more so the fitting is attached to the Armor. Ac cable is not approved for outdoors.
 
  #11  
Old 12-26-12, 06:40 PM
Member
Thread Starter
Join Date: Jul 2009
Location: NYC
Posts: 302
I thought the setscrew was the more common approach for BX/AC cable.
Been using this type on BX(AC) for years...

 
  #12  
Old 12-26-12, 07:42 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: Twin Cities, MN
Posts: 11,981
Again, the setscrew type you posted in post #11 is OK for steel armored AC/BX. For aluminum armored AC (which I find to be more common around here) you are required to use the squeeze type fittings you have in the picture of post #5.

The difference between an AC squeeze type connector, and a NM type connector, is the NM type will not have the basket that stops the armor from passing through the connector.
 
  #13  
Old 12-26-12, 08:50 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
I thought the setscrew was the more common approach for BX/AC cable.
Been using this type on BX(AC) for years...
Not for "MC Lite," as we sometimes call aluminum-clad cable around here.
 
  #14  
Old 12-28-12, 11:07 AM
Member
Thread Starter
Join Date: Jul 2009
Location: NYC
Posts: 302
I know the Minisplits as well as *service* outlet they put nears the compressors are 120V.

Bearing it's 3 wire...I presume the neutral is the white going to the busbarr.
With this AC (aluminum flex with bonding wire) - is the bonding wire serving as the ground OR is the bonding wire/metal jacket serving as the ground.

I can't recall whether there was a difference in *ground* for steel vs. alum.
 
  #15  
Old 12-28-12, 04:11 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
I know the Minisplits as well as *service* outlet they put nears the compressors are 120V.
I'm not familiar with the term "Minisplits." Can you describe what you mean by that?

Bearing it's 3 wire...I presume the neutral is the white going to the busbarr.
A white wire connected to the neutral bus would be the grounded conductor, or neutral.

With this AC (aluminum flex with bonding wire) - is the bonding wire serving as the ground OR is the bonding wire/metal jacket serving as the ground.
To the best of my knowledge, it's the two together.

I can't recall whether there was a difference in *ground* for steel vs. alum.
Steel is not as good a conductor as either copper or aluminum, and does not provide the required "low-impedance path to ground" on its own.
 
  #16  
Old 12-28-12, 05:11 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: Twin Cities, MN
Posts: 11,981
Steel is not as good a conductor as either copper or aluminum, and does not provide the required "low-impedance path to ground" on its own.
That is not true. Thousands of miles of steel EMT is used for grounding path in commercial installations.

The bonding strip, in conjunction of the metal armor, is the grounding path.
 
  #17  
Old 12-28-12, 05:58 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,213
I'm not familiar with the term "Minisplits." Can you describe what you mean by that?

This is a mini-split heat pump.

Wall Mounted 18 - 30,000 BTU Heat Pumps - Fujitsu Ductless Mini-Splits
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
'