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View Full Version : Distribution panel upgrade with lots-o-wire nuts



Brian Harwood
04-12-2012, 11:38 AM
Distribution panel in a 1971 home with a 2011 update and it appears all of the old wiring was tied into the breakers via a short length of new wiring and wire nuts. I have seen very few older homes that have been updated and was wondering if this approach is acceptable?

Rick Cantrell
04-12-2012, 11:55 AM
There is nothing wrong in using wire nuts and a pigtail to add length to a wire in a panel enclosure.

Garry Blankenship
04-12-2012, 02:53 PM
Designated use enclosures are not supposed to be used as junction boxes. That position relates more to conductors feeding through or not germane to the enclosure. The real thrust of this is having adequate space to see / trace wires and it is very loosely enforced. Enforcing it can involve calculating the "cross sectional area"; how much is available, how much is used and after determining all that, is it in compliance ? Your application is fine.

Robert Meier
04-12-2012, 03:06 PM
Designated use enclosures are not supposed to be used as junction boxes. That position relates more to conductors feeding through or not germane to the enclosure. The real thrust of this is having adequate space to see / trace wires and it is very loosely enforced. Enforcing it can involve calculating the "cross sectional area"; how much is available, how much is used and after determining all that, is it in compliance ? Your application is fine.

IMO it is physically impossible to exceed the 75% maximum fill for splices in a panel.


312.8 Enclosures for Switches or Overcurrent Devices.
Enclosures for switches or overcurrent devices shall not be used as junction boxes, auxiliary gutters, or raceways for conductors feeding through or tapping off to other switches or overcurrent devices, unless adequate space for this purpose is provided. The conductors shall not fill the wiring space at any cross section to more than 40 percent of the cross-sectional area of the space, and the conductors, splices, and taps shall not fill the wiring space at any cross section to more than 75 percent of the cross-sectional area of that space.

Garry Blankenship
04-12-2012, 03:42 PM
IMO it is physically impossible to exceed the 75% maximum fill for splices in a panel.

You're probably right with newer enclosure sizes, but part of making that decision is determining how much, ( what % ), of the enclosure space is already taken by the panel interior/circuit breakers/landing pads/etc or the fused switch guts or whatever. Then you add the wires, any splices, etc and it adds up fast. Especially fast when there is non-device related wiring passing through and/or spliced in there. It is a tough battle to wage. I have seen it called and it was justifyable.

Rod Corwin
04-13-2012, 06:45 AM
The main thing to watch for in these type installations is making sure they did not attach 12ga wire to 14ga wire with a 20amp breaker. Would need to be 15amp breaker and preferably 14ga pigtail to eliminate confusion.

Al Neuman
04-13-2012, 07:40 AM
It's perfectly acceptable to have splices in the panels.

It's not, however, to have a doorbell transformer. The transformer's primary leads are double tapped off of a breaker. The secondary leads, if standard #18 bell wire, are not insulated for the voltage present in the panel.

Rick Cantrell
04-13-2012, 07:44 AM
...
It's not, however, to have a doorbell transformer. The transformer's primary leads are double tapped off of a breaker. ...

Good catch,