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Ready Mix concrete plant electrician
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Discussion Starter · #1 ·
Does Square D make a non slash rated single pole plug on style breaker? I’m going to be naughty and use the C phase (red taped high leg) for some small unit heaters if such a breaker exists. The panel is full and not only double tapped, but triple and worse because of stupid people. The C phase would really help out cleaning up this panel in a plant I have. I know it’s not really right, but I’ve done it before with slash rated breakers when I had a bit of an emergency.
The 208ish power worked just fine but at a slightly lower level of heat. This is a project that I have several months to get to before heating season begins.
 

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Bilge Rat
motors and controls.........
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Does Square D make a non slash rated single pole plug on style breaker? I’m going to be naughty and use the C phase (red taped high leg) for some small unit heaters if such a breaker exists. The panel is full and not only double tapped, but triple and worse because of stupid people. The C phase would really help out cleaning up this panel in a plant I have. I know it’s not really right, but I’ve done it before with slash rated breakers when I had a bit of an emergency.
The 208ish power worked just fine but at a slightly lower level of heat. This is a project that I have several months to get to before heating season begins.
I've never seen a non-slash single pole QO but I have seen 240/415 QOs.

The part # for a 20 amp single pole is QOXD120. They come in10, 16, 20, 32 and other European amperages.

The only bad thing is they are 3KAIC. If the system is an open ∆, then the available fault current is limited to what the ∆ pot can come up with. If it's a closed ∆, the fault current would be higher because all 3 pots will contribute.

As far as using the high leg to neutral goes, it'll work just fine. It won't cause a voltage imbalance on the other phases even if it's an open ∆. Even the PUCO meter will read correctly, that's why the high leg is phase C.

If it were me, and the heaters were 3000 watts or smaller, I'd get the 16 amp model just so I could see the strange looks when people see 16 on a breaker handle.......but that's just my oddball personality.........lol.
 

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Discussion Starter · #3 ·
Yeah I realize that using the high leg won’t really cause harm, it’s just that most people are scared by the old wives tales so I said naughty.

I’m on a full Delta bank, 150kva to be exact and the secondary drop is pretty short, like 25’ so the fault current is going to be high. Looks like this may have reached a dead end as 3k probably is too sketchy. The last thing I need is to have a hard fault in a heater and dynamite a breaker and take out a bunch of other circuits and crash a plant.

I know this has been discussed ad-nauseum but open Deltas are uncommon around here, if you see one it’s likely open star primary.
 

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Bilge Rat
motors and controls.........
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With a 150 KVA closed ∆, the impedance of the transformers would need to be more than 10% in order to have less than 3KA of available fault current. Not likely to be that high.......

Oh well, at least we tried......lol.
 

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What about getting straight rated 2 poles and using the high leg with A or C phase? Would that help you find enough room in the panel?

Sent from my SM-G970U using Tapatalk
 

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Discussion Starter · #6 ·
What about getting straight rated 2 poles and using the high leg with A or C phase? Would that help you find enough room in the panel?

Sent from my SM-G970U using Tapatalk
I may end up going towards that direction, the high leg would be so much easier to do though. Honesty I need to swap out the panel and stop trying to quick fix the situation, if I source another QO panel I could reuse the breakers I have I suppose.
 
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