Is using the main panel as a junction box a code violation?

Galaxy

New member
This is my very first thread, and I hope someone has an answer...So, recently we experienced quite a few power outages and a lot of people are now buying up generators and wanting to connect them using a transfer switch to the main panel. What I am seeing is when the transfer switch is wired in with its own bank of breakers, the connections to the house are being made in the main panel (and the backed-up normal power breakers abandoned). This is usually done with wire nut connectors. Now, my understanding is that the main panel cannot be used as a junction box, but it seems this is allowed in the US. What is the alternative solution to this? A separate junction box for say 10 circuits outside of the main panel? This makes little sense to me, as the branch circuit wiring to the house will most likely be too short now...suggestions?
 

Adamjamma

Senior Member
difference between NEC and .canadian codes possibly?

NEC allows the connections within the panel box and if you were moving the panel box like six feet you can splice the wires in old box to do that without any problems. Many times the new box is next to old box when you design the generator panel box, so again, not a large problem.

But, do not have the Canadian code book handy. Know some parts of canadian code were used in last code update in Jamaica, but not sure how many were, but the inspector here in Jamaica would allow me to move wires to new breakers using old box as a jumper... though he would prefer I pull new wire ... because we use conduits in most work I do here in Jamaica. But he would not require new wire, just prefer it...
 
Yes it is against Canadian code. CEC 2015. 12-3032(1)

The circuits would have to be removed and installed in the new panel. If they are not long enough a junction box will need to be used.
 

kwired

Electron manager
Since this is the Canadian Forum section what Eddy posted probably applies. I can't say anymore as I don't know Canadian code.

If NEC is what applies, one needs to look at some terminology - a panelboard is the assembly with the bus and breakers, it gets installed into a cabinet. You can make splices inside a cabinet. Kind difficult to make splices inside a breaker or the bus assembly, which are what makes up the "panelboard".
 

BMANN06

Member
I know several years ago it was ok. I started out in residential and performed several service upgrades and fuse to cb swaps where branch circuits were too short. I extended them with a joint in the panel and the ESA inspector had no problem with this. This was in the mid 2000's, I don't really keep up with current residential codes anymore but its worth checking in with your inspector.

my $0.02
 
I know several years ago it was ok. I started out in residential and performed several service upgrades and fuse to cb swaps where branch circuits were too short. I extended them with a joint in the panel and the ESA inspector had no problem with this. This was in the mid 2000's, I don't really keep up with current residential codes anymore but its worth checking in with your inspector.

my $0.02
Making a splice in a panel is ok when adding to an existing installation as long as the wires and joints don’t take up more than 75% of the space.

Using a panel as a junction box for conductors feeding through or tapping off to other apparatus, like conductors fed from another panel, is not allowed.

12-3032 + 62-212
 

BMANN06

Member
Making a splice in a panel is ok when adding to an existing installation as long as the wires and joints don’t take up more than 75% of the space.

Using a panel as a junction box for conductors feeding through or tapping off to other apparatus, like conductors fed from another panel, is not allowed.

12-3032 + 62-212
Can't argue with that - although if I was the OP I would contact local inspector and get his input - if the originating panel is piped with a nipple over to the backup panel I don't think he'll have a problem with said joint. However I'm not an inspector.
 

DanS26

Member
IMO the Canadian code requirement does keep the rats nest of wire nuts out of the main distribution panel.
 

kwired

Electron manager
IMO the Canadian code requirement does keep the rats nest of wire nuts out of the main distribution panel.
Does it really matter or impact safety if you moved the rats nest to a junction box right next to main panel for those conductors too short to reach their terminal.
 
Does it really matter or impact safety if you moved the rats nest to a junction box right next to main panel for those conductors too short to reach their terminal.
Wires that are too short to reach the breakers can be extended as long as the space does not get filled more than 75%. What can not be done is using the panel as a junction for circuits that do not originate from that panel.
 

kwired

Electron manager
Wires that are too short to reach the breakers can be extended as long as the space does not get filled more than 75%. What can not be done is using the panel as a junction for circuits that do not originate from that panel.
So the rule is more about not having circuits inside that don't originate inside or are supplying the panel, and less about splicing inside?
 
So the rule is more about not having circuits inside that don't originate inside or are supplying the panel, and less about splicing inside?
Yes. There are two rules.

First one says “ enclosures for overcurrent devices, controllers and externally operated switches shall not be used as a junction boxes, troughs or raceways for conductors feeding through to other apparatus”. ​12-3032(1)


The other says. “The enclosure identified shall be permitted to be used as a junction box where wiring is being added to an enclosure forming part of an existing installation and the conductors, splices and taps do not fill the wiring space more than 75%”. 12-3032(2)(a)(i)
 

BMANN06

Member
Wires that are too short to reach the breakers can be extended as long as the space does not get filled more than 75%. What can not be done is using the panel as a junction for circuits that do not originate from that panel.
Agreed, and if you pipe two panels together they are technically considered one panel.
 
Agreed, and if you pipe two panels together they are technically considered one panel.

??? What do you mean by pipe two together?

You can can not have wires connected to a breaker in one panel leave, and then run through conduit to another panel, and then exit the second panel to the field.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
You can can not have wires connected to a breaker in one panel leave, and then run through conduit to another panel, and then exit the second panel to the field.
It's done with almost every residential generator-panel installation.
 

BMANN06

Member
??? What do you mean by pipe two together?

You can can not have wires connected to a breaker in one panel leave, and then run through conduit to another panel, and then exit the second panel to the field.
I'm not arguing that your are not right to the letter of the law, I have done this before (in ontario) on a few occasions and got my ESA sticker with no questions asked. I think if your were doing a new installation with a generator panel and had joints in a panel the inspector would be shaking his head and likely force the noted codes. However in an existing installation (ie retrofitting a generator panel) there isn't a whole lot that you can do without a joint somewhere. That being said, I haven't done rezzy work for awhile so the ESA may have firmed up their stance on this since.
 
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