I have a Multiwire Branch Circuit connected to two 15A Breakers (Handle tied together). Each circuit only has 2 duplex receptacles on it that are seldomly used. Is it acceptable to combine both the HOTs together and pigtail to only 1 of the 15A breakers? I would than remove the Handle Tie and use the renamed 15A Breaker for a new circuit.
- the two hot conductors do not rejoin at any point (we know this because you'd have a 240V short on your hands otherwise), making it so that the rules about wires in parallel don't apply
- the two hot conductors are being protected by the same breaker in the new configuration (i.e. two 14AWG hots on the same 15A breaker, returning via a 14AWG neutral), eliminating the possibility of an overloaded neutral, and
- this is all on one breaker, making it all part of one branch circuit and avoiding a violation of 200.4(A) regarding shared neutrals
you can go ahead and do this safely by wirenutting both hots to a pigtail from the chosen breaker in the panel. (312.8 allows splicing in the panel provided you aren't overflowing the gutter space.)
I would put a tag on the wires in the cable saying "Same Leg" at the various boxes this feeds though to avoid confusion between this (admittedly somewhat odd) configuration and an actual multi-wire branch circuit.
My only concern comes from the IAEI (International Association of Electrical Inspectors).
*Question: Can a UL Listed product be modified in the field if the manufacturer indicates that the revision is ok and sends out new parts?
Answer: The UL Mark applies to products as they were originally manufactured. UL does not know the effect modifications in the field will have on a product. Therefore, unless the modifications are specifically tested and evaluated by UL, UL cannot say that the modifications void the UL Mark, or that the product continues to comply with UL’s safety requirements. The exception would be when the product has specific replacement markings.*
So why not just replace the breakers, cost is not relevant and everyone is happy.
Short answer: No, not like that.
You have to remove one of the wires in the panel and cap it off.
Then go to each receptacle that was on that wire and rewire it to the remaining hot wire instead of the disconnected one. Cap off the disconnected wire at each receptacle.
Then you are good.
Good luck and stay safe!