Panelboard Questions

You would need to look at the label inside the load center to see which spaces are listed for twin/tandem circuit breakers. I would guess only a few spaces are.
 
Little Bill said:
How do those breakers with two handles work? I don't recall ever seeing those. I'm referring to the ones with the blue paint. I see the tandems that are stacked but are the ones with two handles also tandems?
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Yes. There are terminals to attach wires to for each handle. This is how QO originally made tandems, like 700 years ago.
 
You could certainly operate each of those handles and verify the paint contamination is not giving any obvious trouble. Other than that the biggest problem that panel has from this view is bad labelling.
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"Allowed" is funny wording. If it was legally installed originally nothing in the building code compels a proactive replacement. Much older panels are still happily working to this day. Just watch out for signs of failure. And watch for FPE or Federal Pacific breakers, which fail to trip in a way that won't be apparent on inspection.
 
As stated, those were the original QOT breakers
 
The QO tandem breaker was built using the fronts back style up until the mid 80s.

The two side-side tandem on the left hand side are not QO from Square D. Are they classified ones from another vendor?
 
jim dungar said:
The two side-side tandem on the left hand side are not QO from Square D. Are they classified ones from another vendor?
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For a while, Square D sold a "kit" that allowed you to tie the HANDLES of side-x-side tandems together to create a "quasi" quad, but they pulled it after a while, likely because of misuse. Handle ties do not qualify as "common trip", which is required if the load is 120/240V, such as a dryer or some air conditioners, where the main load is 240V by the blower motor is 120V. So that "quad" is possibly not legit.
 
Jraef said:
For a while, Square D sold a "kit" that allowed you to tie the HANDLES of side-x-side tandems together to create a "quasi" quad, but they pulled it after a while, likely because of misuse. Handle ties do not qualify as "common trip", which is required if the load is 120/240V, such as a dryer or some air conditioners, where the main load is 240V by the blower motor is 120V. So that "quad" is possibly not legit.
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The handle ties on the 30s at the bottom look like the genuine QO kit I remember. The handle tie on the 20s bottom left looks ... custom.
 
Nothing else fits the QO panel other than QO breakers unlike HOM that some can install other brand breakers but just not "legally", as nothing listed for Square D panel other than Square D breakers.

The breakers shown, the old "piggyback" or the other "side by side", both are examples of tandem breakers and were made by SD for their QO panels, and are allowed. The Piggybacks might be weak as they are quite old, and can be replaced by a "side by side" tandem. I don't think the old QO had any rejection device that limited the placement of the Tandem breakers, but it might not have been listed for tandem use. If the panel model is something like QO 20-40M it likely can have up to 20 tandems added.
 
Little Bill said:
How do those breakers with two handles work? I don't recall ever seeing those. I'm referring to the ones with the blue paint. I see the tandems that are stacked but are the ones with two handles also tandems?
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Not only that, many of them had push-in terminals instead of screw terminals. I couldn't find a pic showing the holes, but note in the first pic that there is no terminal screw hole:

1716332291443.jpeg 1716332352324.jpeg
 
LarryFine said:
Not only that, many of them had push-in terminals instead of screw terminals. I couldn't find a pic showing the holes, but note in the first pic that there is no terminal screw hole:
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Push-in terminals were available but not common across the US.
 
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Fred B said:
Nothing else fits the QO panel other than QO breakers unlike HOM that some can install other brand breakers but just not "legally", as nothing listed for Square D panel other than Square D breakers.

The breakers shown, the old "piggyback" or the other "side by side", both are examples of tandem breakers and were made by SD for their QO panels, and are allowed. The Piggybacks might be weak as they are quite old, and can be replaced by a "side by side" tandem. I don't think the old QO had any rejection device that limited the placement of the Tandem breakers, but it might not have been listed for tandem use. If the panel model is something like QO 20-40M it likely can have up to 20 tandems added.
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QO panels have been made with allowances for tandem breakers since they were introduced in the late 50s, they used the QOxxyy numbering system.
In the 60's the concept of limiting The quantity of tandem breakers came into existence providing us with the acronym CTL, they used the QOTxxyy numbering system.
In the late 80's they changed the tandem breaker from th piggyback to the side by side design, in a strategic (?) marketing decision the part numbering was left unchanged except for the 2 pole version which a quad design with a part number of QO(T)xxyyyyzz.
 
Fred B said:
Nothing else fits the QO panel other than QO breakers unlike HOM that some can install other brand breakers but just not "legally", as nothing listed for Square D panel other than Square D breakers.
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Both Eaton and Siemens make Classified breakers for QO panels. Neither of those are available as quads though, or even tandems for that matter. Just 1 and 2 pole up to 50A
 
Jraef said:
Both Eaton and Siemens make Classified breakers for QO panels. Neither of those are available as quads though, or even tandems for that matter. Just 1 and 2 pole up to 50A
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Interesting, Why would they make such as the "genuine" QO is, for the most part, readily available. Also how would the use of a "Classified" breaker in the SD panel, even though code allowed, effect the SD long standing policy that the use of any breaker other than "theirs" would void any panel warranty?
 
Fred B said:
Interesting, Why would they make such as the "genuine" QO is, for the most part, readily available. Also how would the use of a "Classified" breaker in the SD panel, even though code allowed, effect the SD long standing policy that the use of any breaker other than "theirs" would void any panel warranty?
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My favorite supply house is a Siemens and Eaton distributor. But they sell those classified breakers because they don't want their customers going somewhere else to get a QO breaker. In other words, money is why they exist.
 
jim dungar said:
The two side-side tandem on the left hand side are not QO from Square D. Are they classified ones from another vendor?
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Jim, those look like Square D tandems to me. QO20303020 is a set of (1) 2030 and (1) 3020

The inner handle tie looks like a Square D but not sure about the outer handle tie.
 
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