panels

kwired

Electron manager
Location
NE Nebraska
This can not be the typical split bus panel we have seen in past where there is one set of main lugs that is supplying two separate sections of bus. It is describing a panel with multiple feeders supplying it. I can not recall ever seeing such an animal.
The panel I was initially talking about was the ones we used to see that had main lugs that fed 12 poles which if you installed six 2 pole breakers you have your allowed service disconnecting means. One of those 2 pole breakers served as the lighting main for the second bus section in the panel. The panel only has one supply but is split possibly six ways.

The panel that Augie submitted a schematic for I have also seen - but they were all old Pushmatic 200 amp panels. They had 200 amp main lugs that supplied two 100 amp main breakers - each supplying a separate set of bus bars. It was usually a left set and right set instead of top set and bottom set. This panel still only has one feed to it and is then split. Maybe I don't read it right but the way it is written I understand the exception in question to mean the panel has two supplies to it. Take the schematic for the one Augie submitted. It likely has 200 amp main lugs and 200 amp bus on supply side of the main breakers. Is that not still an extension of the feeder supplying the panel? Then after each main we have two sub feeders of 100 amps each protected by 100 amp OCPD. Is this one panelboard or two within same cabinet?

But then we have UL guys and CMP info that suggests this is what it was intended to apply to so :slaphead:

I don't think you will find such an animal with any new equipment, and the older ones that are still out there were likely limited to 42 circuits at the time they were made so I don't think it is really much of a problem anyway.
 

Lady Engineer

Senior Member
Location
New Jersey
I know that Lighting and appliance panels were limited to 42 poles, but Power panels were allow more that 42 poles. I thought this changed in the 2008 code, not 2011.

Sorry guys, I'm late. :D

*disclaimer* I'm not here to argue, but I was looking for other information and wanted to drop in to say hi. lol :p
 
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resistance

Senior Member
Location
WA
I know that Lighting and appliance panels were limited to 42 poles, but Power panels were allow more that 42 poles. I thought this changed in the 2008 code, not 2011.

Sorry guys, I'm late. :D
Better late than never, and your input helps regardless?unless it?s a repeat:slaphead::D
 

resistance

Senior Member
Location
WA
Not sure how I would interpret that post.

Did you thank her, insult her, or make a joke I did not get?
Neither!! It?s what I said: It?s better to give your input, rather than not. Which means?in this case: It may help us better understand the topic. Never having another view on the topic would mean we would never know if we covered all our basis??unless it?s a reapt of what someone else said.

Better late than never is a widely used saying. Just an old school saying.
 

jmellc

Senior Member
Location
Central NC
Remember that you were never really limited before except in a lighting and appliance panel.
So John, a friend across town came across a QO panel, 40 space, with 3 tandems, bringing up to 43 circuits. Under old rules, it exceeded by one, correct? Under new rules, is it OK in your opinion?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
So John, a friend across town came across a QO panel, 40 space, with 3 tandems, bringing up to 43 circuits. Under old rules, it exceeded by one, correct? Under new rules, is it OK in your opinion?
Not okay simply because the panel was not designed to be used for more than 40 circuits. It is a violation of the listing-- 110.3(B)
 
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