 |
|
06-11-2012, 02:29 PM
|
#1
|
|
Member
Join Date: May 2011
Location: Tucson,AZ
Posts: 103
|
Maximum wires in a 2 1/2" nipple
My main service panel is mounted on an exterior wall. I have a 2 1/2" x 10" nipple connected to the back of the panel going through to the interior of a sheetrock wall. I am doing some rewire and adding new circuits. Is there a maximum number of wires allowed in the nipple?
|
|
|
Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. DIYChatroom.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any home improvement task!
|
06-11-2012, 02:56 PM
|
#2
|
|
Licensed electrician
Join Date: Sep 2007
Location: Maryland
Posts: 6,035
|
Maximum wires in a 2 1/2" nipple
What is on the other side of the nipple?
__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
|
|
|
|
|
06-11-2012, 03:07 PM
|
#3
|
|
Member
Join Date: May 2011
Location: Tucson,AZ
Posts: 103
|
Maximum wires in a 2 1/2" nipple
Quote:
Originally Posted by Jim Port
What is on the other side of the nipple?
|
The nipple extends through the exterior brick wall into a sheetrock wall. The wall is open from the inside and wires are being pulled from various points in the house through a ceiling chase.
|
|
|
|
|
06-11-2012, 03:30 PM
|
#4
|
|
Member
Join Date: May 2009
Location: Easton MD
Posts: 1,827
|
Maximum wires in a 2 1/2" nipple
I am seeing 60% fill and no derating here. No?
Chapter 9, T1, Note(4) Where conduit or tubing nipples having a maximum
length not to exceed 600 mm (24 in.) are installed between
boxes, cabinets, and similar enclosures, the
nipples shall be permitted to be filled to 60 percent of
their total cross-sectional area, and 310.15(B)(3)(a) adjustment
factors need not apply to this condition.
Last edited by Code05; 06-11-2012 at 03:34 PM.
|
|
|
|
|
06-11-2012, 03:44 PM
|
#5
|
|
Licensed electrician
Join Date: Sep 2007
Location: Maryland
Posts: 6,035
|
Maximum wires in a 2 1/2" nipple
I was concerned about branch circuits being mixed with unfused service conductors.
I agree on the 60%, no derate.
__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
|
|
|
|
|
The Following 2 Users Say Thank You to Jim Port For This Useful Post:
|
|
|
06-11-2012, 03:48 PM
|
#6
|
|
Member
Join Date: May 2009
Location: Easton MD
Posts: 1,827
|
Maximum wires in a 2 1/2" nipple
Quote:
Originally Posted by Jim Port
I was concerned about branch circuits being mixed with unfused service conductors.
I agree on the 60%, no derate.
|
If service conductors are involved, I agree, we have a no go.
|
|
|
|
|
06-11-2012, 03:53 PM
|
#7
|
|
Member
Join Date: May 2011
Location: Tucson,AZ
Posts: 103
|
Maximum wires in a 2 1/2" nipple
Quote:
Originally Posted by Jim Port
I was concerned about branch circuits being mixed with unfused service conductors.
I agree on the 60%, no derate.
|
How do I know when I am at 60%? I could just measure but is there some thing else to consider?What is the reason for this limitation?
|
|
|
|
|
06-11-2012, 03:56 PM
|
#8
|
|
Member
Join Date: May 2011
Location: Tucson,AZ
Posts: 103
|
Maximum wires in a 2 1/2" nipple
Quote:
Originally Posted by Code05
If service conductors are involved, I agree, we have a no go.
|
What are service conductors? Conductor supplying main service such as from the power company?
Last edited by elmaur; 06-11-2012 at 04:06 PM.
|
|
|
|
|
06-11-2012, 04:19 PM
|
#9
|
|
Member
Join Date: May 2009
Location: Easton MD
Posts: 1,827
|
Maximum wires in a 2 1/2" nipple
Quote:
Originally Posted by elmaur
What are service conductors? Conductor supplying main service such as from the power company?
|
Yes. They are unfused, except at the pole/tranformer.
|
|
|
|
|
06-11-2012, 04:22 PM
|
#10
|
|
Member
Join Date: May 2009
Location: Easton MD
Posts: 1,827
|
Maximum wires in a 2 1/2" nipple
Quote:
Originally Posted by elmaur
How do I know when I am at 60%? I could just measure but is there some thing else to consider?What is the reason for this limitation?
|
Heat and insulation breakdown. Do you need us to explain pipe fill and how to calculate it, it is not hard.
|
|
|
|
|
06-11-2012, 04:23 PM
|
#11
|
|
Licensed electrician
Join Date: Sep 2007
Location: Maryland
Posts: 6,035
|
Maximum wires in a 2 1/2" nipple
To figure the 60% you would need to compute the area of the conductors to be installed vs 60% of the cross sectional area of the 2" nipple.
These values are computed for you in the Chapter 9 Tables of the NEC.
__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
|
|
|
|
|
06-11-2012, 05:30 PM
|
#12
|
|
Member
Join Date: May 2011
Location: Tucson,AZ
Posts: 103
|
Maximum wires in a 2 1/2" nipple
Quote:
Originally Posted by Code05
Heat and insulation breakdown. Do you need us to explain pipe fill and how to calculate it, it is not hard.
|
I may not need to calculate. I think I'll use another knockout on the back of the panel and divide the wire pulls between the 2 entry points and probably should be good.
|
|
|
|
|
06-11-2012, 06:24 PM
|
#13
|
|
E2 Electrician
Join Date: Apr 2012
Location: Litchfield, CT
Posts: 3,116
|
Maximum wires in a 2 1/2" nipple
Quote:
Originally Posted by elmaur
I may not need to calculate. I think I'll use another knockout on the back of the panel and divide the wire pulls between the 2 entry points and probably should be good.
|
You could easily install 264 #12 THHN, THWN conductors in a 2 1/2" nipple, I doubt you'll go over... lol... This was using EMT as your nipple, but regardless... I seriously doubt you will have any issues.
Last edited by stickboy1375; 06-11-2012 at 06:26 PM.
|
|
|
|
06-11-2012, 06:29 PM
|
#14
|
|
E2 Electrician
Join Date: Apr 2012
Location: Litchfield, CT
Posts: 3,116
|
Maximum wires in a 2 1/2" nipple
Quote:
Originally Posted by elmaur
My main service panel is mounted on an exterior wall. I have a 2 1/2" x 10" nipple connected to the back of the panel going through to the interior of a sheetrock wall. I am doing some rewire and adding new circuits. Is there a maximum number of wires allowed in the nipple?
|
By the way, is there a junction box or were you sleeving cables through this nipple?
|
|
|
|
|
06-11-2012, 09:18 PM
|
#15
|
|
Member
Join Date: May 2011
Location: Tucson,AZ
Posts: 103
|
Maximum wires in a 2 1/2" nipple
Quote:
Originally Posted by stickboy1375
By the way, is there a junction box or were you sleeving cables through this nipple?
|
No junction box. My wire pulls are coming from various areas in the house and through the nipple into the main service panel.
|
|
|
|
-->
| Thread Tools |
Search this Thread |
|
|
|
| Display Modes |
 Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
|
