Is it possible to have two 240V circuits on this main breaker lug?

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brycenesbitt

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Are there breakers allowing two 240V circuits on these Mid-1960's era main meter lugs (see picture)?
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The main lugs are solid.
A Type QT Seimens quadplex Q23050CT2U would be perfect, except for the rejection clips (as I understand it Type QP takes
solid lugs, and Type QT requires a notched bus bar).

The breakers don't look original to the panel, but were installed with permit during subpanel upgrades a few years back, per permit records. Panel is probably GE, breakers are Siemens. No idea.
PXL_20231117_215046350.jpg100 amps rating label.jpg
Building constructed 1965.
 
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Ok, think I got it. The listing issue remains, but the physical issue is solved by the
Eaton BRDC series (e.g. BRDC230230) which is built without the rejection clip, and a decedent of the Westinghouse Quicklag P & PL.

Based on

Circuit total limitation - Wikipedia

en.wikipedia.org en.wikipedia.org
The 1965 edition of the NEC, article 384-15 was the first reference to a circuit total limitation of panelboards, leading to vendors introducing mechanical means to limit the number of breakers a given panel could take (regardless of total amps). The 2008 NEC altered 408.54 the previous 42 circuit limitation on panelboards, and Eaton as of 2019 removed the restriction ""for replacement use only" from the BRDC series.
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So in short a CTL breaker only fits in deliberately limited panel spots.
A non-CTL breaker will fit in either limited or full spots.
CTL Tab.JPG

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That said: The entire idea of the NEC trying to limiting ampacity by limiting breaker spots seems suspect.
Limiting breakers does not in fact limit amps in any real way: it's possible to overload any panelboard by combining loads after the breakers, and no physical panel board can read the amp reading on any given breaker to come up with a total, nor predict what the actual load from the branches will be.

408.54 in the 2008 code

On a residential remodel may a twin breaker be added to an existing 42 circuit panel. I did a load calculation and there is lots of capacity. Is this allowed per 408.54 in the 2008 code?
forums.mikeholt.com
 
No, if the panel is rated for 42 circuits then it was not designed for twins. The code has changed and you can actually get a 60-circuit panel. I don't believe there is any limit on the number of circuits, however, you do have to follow the manufacturers' instructions.
 
brycenesbitt said:
The 1965 edition of the NEC, article 384-15 was the first reference to a circuit total limitation of panelboards, leading to vendors introducing mechanical means to limit the number of breakers a given panel could take (regardless of total amps). The 2008 NEC altered 408.54 the previous 42 circuit limitation on panelboards, and Eaton as of 2019 removed the restriction ""for replacement use only" from the BRDC series.
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So in short a CTL breaker only fits in deliberately limited panel spots.
A non-CTL breaker will fit in either limited or full spots.
---
That said: The entire idea of the NEC trying to limiting ampacity by limiting breaker spots seems suspect.
Limiting breakers does not in fact limit amps in any real way: it's possible to overload any panelboard by combining loads after the breakers, and no physical panel board can read the amp reading on any given breaker to come up with a total, nor predict what the actual load from the branches will be.
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I have Square D literature from 1960 showing load centers rated for a limited number of tandem breakers.It appears people did not follow the manufacturer's instructions so the NEC added a specific requirement and UL created their CTL listing.
As far as I remember, circuit limitation was about panel fill and not really circuit ampacity. Load enter bus rating are based on temperature rise which is impacted by physical room in the enclosure. This was a real problem up to the early 80's when UL increased enclosure requirements and 14" wide load centers became the norm.
 
jim dungar said:
As far as I remember, circuit limitation was about panel fill and not really circuit ampacity. Load enter bus rating are based on temperature rise which is impacted by physical room in the enclosure. This was a real problem up to the early 80's when UL increased enclosure requirements and 14" wide load centers became the norm.
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The temperature rise of stuffing a more breakers in pales compared to the impact of AFCIs which create heat 24/7 regardless of how many amps are flowing through them. Where was the heat concern as AFCI's were spreading?
 
Dennis Alwon said:
No, if the panel is rated for 42 circuits then it was not designed for twins. The code has changed and you can actually get a 60-circuit panel. I don't believe there is any limit on the number of circuits, however, you do have to follow the manufacturers' instructions.
Click to expand...
The pictured panel is a main breaker in an apartment. It's not clear it has or ever had a rating for number of circuits.
It's got a rating for amps though, that number is 100A.
 
brycenesbitt said:
The temperature rise of stuffing a more breakers in pales compared to the impact of AFCIs which create heat 24/7 regardless of how many amps are flowing through them. Where was the heat concern as AFCI's were spreading?
Click to expand...
The heating concern seems to have disappeared about the same time the 42 circuit limit did.
 
But hard to get and expensive. And he'd be downsizing the existing breaker rating. And risking grandfathering of a service panel no longer compliant with 230.

Just install a small sub fed with a 90 A breaker.
 
Looks like a 200A meter can with provisions for 2-100A breakers, doubt a new one would have notched stabs.
 
norcal said:
Looks like a 200A meter can with provisions for 2-100A breakers, doubt a new one would have notched stabs.
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Some meter/main panels of a certain vintage have one set of unnotched stabs and one set of notched stabs. I deduce that the intention was to limit them to six service disconnect handles: two single poles and two tandems. However most of them have a 100A subpanel breaker and an air-conditioner breaker. The notched stabs were nice for quadding up the air-conditioner to add solar. It was slightly annoying if the original electrician had put the 100A sub breaker on the notched stabs.

Such panels are no longer compliant for new services.
 
Are they Circle AW? The look like they made them I have never seen a notched stab on a Circle AW meter can (now Eaton B-Line).
 
norcal said:
Are they Circle AW? The look like they made them I have never seen a notched stab on a Circle AW meter can (now Eaton B-Line).
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Whatever paper label was once on the door is long gone. No idea. The stamped rating label lists a lot of GE breakers? The building was building 1965. What could I look at or photograph to tell the difference? Is Circle AW certified interoperable with Eaton B-Line meter packs?
 
I have never seen a meter stack listed for twin/quad breakers.

Quad breakers are not available in GE and never available in Quicklag so its obvious this panel is not listed for quad breakers.

The label clearly states which breakers are listed.
 
curt swartz said:
Quad breakers are not available in GE and never available in Quicklag so its obvious this panel is not listed for quad breakers.
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Eaton Bulletin FTC-100M3 describes Quicklag Residential as "Type BR". Is there a safety reason to be concerned with the use of Type BR or BRDC on a Quicklag lug: how would the meter pack know the difference if the lug is the same? The BRDC is still type BR and compatible with all non-notched BR panels. If the AHJ approves the installation, is there any reason to be concerned?
 
Even if Eaton states you can use Eaton BR breakers in place of Quicklag breakers that doesn't mean you can choose any BR breaker.
The non-notched twin/quad breakers are marked for replacement use only. They were designed for older non CTL panels. The older panels still had a label showing the locations that you were allowed to use the twin/quad breakers. The panels were not listed to just put them anywhere. If I were inspecting your installation I would ask you to show me the panel manufactures label showing that twin/quad breakers were acceptable.

You can do whatever you want but don't expect all inspectors to accept it just because you think its ok.
 
Its always a potential failed inspection when the panel label is missing. I've gone as far as asking our techs and clients to look to see if the neighbors in the subdivision have the same panel and if any of them have the labels still there. (Not likely to make sense in this case I realize.) I'm sure I've gotten away with some and also played it safe on some.
 
curt swartz said:
The non-notched twin/quad breakers are marked for replacement use only. They were designed for older non CTL panels.
You can do whatever you want but don't expect all inspectors to accept it just because you think its ok.
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Maybe I'll check with the AJH on their preference:
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1) A 50A/30A twin/quad BR, on the full size BR lugs.
2) A pigtail out to a separate spa panel, with the exact same BR twin/quad breaker.
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In an area with 80-100 year old homes everywhere they don't usually sweat "in theory only" items too much. I'm not at all embarased to show them at 58 year old panel and say I'm just trying to make it work safely with today's available equipment.
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Note: For better or worse Eaton removed the "for replacement only" label from the BRDC breakers after the NEC removed the 42 circuit limit. Now they are simply full tab breakers differing from the BR series only in the rejection tab. Absolutely identical product.

Its always a potential failed inspection when the panel label is missing.
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If you look at the first photo, there's a stamp listing the breaker types.
So maybe there never was a paper label -- that might be all there ever was?
 
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