ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals

ECN Shout Chat
Top Posters(30 Days)
Admin 17
Recent Posts
Old decora style outlets
by Admin. 03/25/17 11:40 AM
ESA Arc flash course
by TheShockDoctors. 03/24/17 10:15 AM
fuse rejectors
by HotLine1. 03/24/17 07:53 AM
Another Forum Update
by Admin. 03/22/17 03:04 PM
Dining room plugs
by watersparkfalls. 03/21/17 10:31 PM
New in the Gallery:
SE cable question
Popular Topics(Views)
231,451 Are you busy
166,159 Re: Forum
160,618 Need opinion
Who's Online Now
0 registered members (), 48 guests, and 11 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
Page 1 of 2 1 2
#6965 - 01/16/02 05:30 PM Splicing in Panelboard  
Frank Cinker  Offline
Member
Joined: Jul 2001
Posts: 311
Pennsylvania
We have a flush mounted 100A. 20 circuit sub panelboard at one of our facilities. It's loaded to less than 50% ampacity. There are no spare spaces remaining. All of the 20 circuit breakers have a wire attached to it. Many of the circuits have a very small load on it. Would it be proper/legal to "double up" on some of the circuit breakers by splicing two circuits together in panelboard with pigtail of one wire to one breaker? We need to free up two spaces for a new 2 pole circuit.


Work Gear for Electricians and the Trades

#6966 - 01/16/02 10:43 PM Re: Splicing in Panelboard  
Anonymous
Unregistered

Frank,

Might I suggest using tandem breakers instead of "doubling up" on the breakers? They are readily available for most panels. I know GE and Square D make them for their panels. They will allow you to keep the circuits seperated like they are now and probably intended to be. Saves a lot of trouble down the road.


#6967 - 01/16/02 10:44 PM Re: Splicing in Panelboard  
Bill Addiss  Offline
Member
Joined: Oct 2000
Posts: 3,875
NY, USA
Frank,

Not a problem. Splices are OK as long as there's room for them.

Bill


#6968 - 01/16/02 10:55 PM Re: Splicing in Panelboard  
Redsy  Offline
Member
Joined: Mar 2001
Posts: 2,056
Bucks County PA
If you're certain that the load on 2 particular branches is that light, there should be no reason you can't combine them with a pigtail. I wouldn't do it as regular practice though. Art 373-8 ('99 code. sorry, I don't feel like going to my truck) allows the splice.
Remember some breaker terminals will accomodate 2 terminations. Sq.D QO, for one. And I believe Pushmatics design permits it as well.


#6969 - 01/17/02 09:35 AM Re: Splicing in Panelboard  
Steve Miller  Offline
Member
Joined: Aug 2001
Posts: 325
Loudoun Cty, VA
I always use the pigtail method. We use mostly SQ D & our local SQ D rep told me that even though the QO breakers have 2 "tunnels" for wires they are only (UL) approved for one. He had no idea why SQ D puts 2 "tunnels" on the pressure clamp. (And our local inspectors will usually not allow two on the CB.)


#6970 - 01/17/02 09:56 AM Re: Splicing in Panelboard  
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
If you combine two branch circuits, make sure that they are not parts of a multiwire branch circuit to avoid possible overload on the grounded conductor.
Don(resqcapt19)


Don(resqcapt19)

#6971 - 01/17/02 11:00 AM Re: Splicing in Panelboard  
JBD  Offline
Member
Joined: Jul 2001
Posts: 599
WI, USA
Steve Miller,
Go back and talk to your Square D rep again. I have a QO breaker in my hands the wiring diagram shows 2 wires and the UL label gives torque specs for two wires also.

bigbluewirenut,
Do not use tandem breakers unless your panel is designed for them (it must have a Class CTL label). Never ever put more circuits into panel than it is listed for.


#6972 - 01/17/02 06:30 PM Re: Splicing in Panelboard  
Anonymous
Unregistered

What is the difference between a panelbox that will allow tandem breakers and one that won't? If the panel is old and missing the CTL label is it possible that tandem breakers are still OK? Does the number of neutral wire conncections on the neutral bar mean anything? i.e. there are a lot more holes that spaces for single breakers. Of course some are for different size wires.

The total load on the panel can't increase past the main breaker ampacity of course.


#6973 - 01/17/02 08:35 PM Re: Splicing in Panelboard  
Nick  Offline
Member
Joined: Aug 2001
Posts: 599
Riverside, CA
Never seen tandum breakers in a comercial setting.


#6974 - 01/17/02 10:38 PM Re: Splicing in Panelboard  
Anonymous
Unregistered

Tom:

I am curious as to the difference too? I have never seen a CTL panel that will not accept tandem breakers and I have seen a lot of tandem breakers in use. (Even newly inspected installations that passed.) As you said, you still cannot exceed the amperage rating of the main breaker.


JDB:

"Go back and talk to your Square D rep again. I have a QO breaker in my hands the wiring diagram shows 2 wires and the UL label gives torque specs for two wires also."

My box of 10 20A QO's don't seem to say anything about being rated for 2 wires under the screw?


"Do not use tandem breakers unless your panel is designed for them (it must have a Class CTL label). Never ever put more circuits into panel than it is listed for."

The last time we checked with our Square D rep, ALL QO panels where listed to accept tandem breakers. Rep: "We wouldn't make the breakers, if the panel wouldn't be able to take them."


Are we talking about the same Square D here? Is there a rep in the group that can shed some light here?




[This message has been edited by bigbluewirenut (edited 01-17-2002).]


Page 1 of 2 1 2

Member Spotlight
AllClear
AllClear
Belmond Iowa US
Posts: 44
Joined: August 2005
Show All Member Profiles 
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.023s Queries: 15 (0.004s) Memory: 0.8115 MB (Peak: 0.9888 MB) Zlib enabled. Server Time: 2017-03-25 21:42:19 UTC