Panelboard Main Breaker

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rroark0003 said:
Can a three panel with a main be use on a single phase service?
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Yes, but you should not wire the third phase input rather than tying it to one of the others.
Otherwise you risk overloading the neutral when setting up MultiWire Branch Circuits (MWBCs).
So you will only be able to use 2/3 of the breaker pole spaces in the panel.
 
rroark0003 said:
Does it matter which two of the three lugs on the three phase breaker are used? Also, is there a NEC reference?
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The NEC is silent on the subject, except in the general rule that the instructions of the panelboard maker must be followed.
If the manufacturer says not to use it for three wire single phase, then you would be out of luck.

The only preference that I see is the convention that in a high leg delta the "different" leg, the high leg, must be landed on the B phase line.
By leaving the B phase unconnected you are in parallel with that same idea, even though it is not a requirement.
 
One risk to remember is that 1/3 of your slots will not be usable so if someone in the future doesn't figure that out, they will cause problems for themselves. It unnecessarily complicates things for the sake of not having to buy the correct equipment.
 
GoldDigger said:
The NEC is silent on the subject, except in the general rule that the instructions of the panelboard maker must be followed.
If the manufacturer says not to use it for three wire single phase, then you would be out of luck.

The only preference that I see is the convention that in a high leg delta the "different" leg, the high leg, must be landed on the B phase line.
By leaving the B phase unconnected you are in parallel with that same idea, even though it is not a requirement.
Click to expand...
Yes, but this would not apply to a single phase SERVICE... ;)
 
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