ECN Forum Forums Code Related Discussion NEC & other Code issues Counting the Neutral as current carrying

It must be the engineer in me, but when I read two wire circuit EACH with its own neutral I see that as 3 wires and 6 of those make 18.

In either case, it's still 50%.

In a 2 wire circuit where one of those wires is a dedicated neutral will always need both wires counted as current carrying, so the outcome is the same regardless.

Thanks Vin, guess I was out in the sun to long the last couple of days.

50% it is.

"Noodle" would be a good definition, as it describes something specifically different per the "Build" of the item, rather than the Operation.

The "Build" in this case would be an active System Conductor, which is intentionally Grounded.

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Per the OP, if the (6) Two-Wire Circuits, each with their own "Neutral" was intended to mean (6) 1 Phase 3 Wire Multiwire Circuits:
12 Ungrounded Conductors, 6 Grounded Common Conductors - total of 18 Conductors;
then the CCC's (Current Carrying Conductors) would be one of the following:

1. If the Multiwire Circuits are derived from a 1 Phase 3 Wire Transformer, then total CCC's would be 12,
2. If the Multiwire Circuits are derived from a 3 Phase 4 Wire Wye, then total CCC's would be 18.

For example "A", there will be 18 Conductors total, but only 12 will carry the FULL LOAD AMPERES.
This example describes a "Balancing Neutral" - possibly a High-Wire Circus Act???

For example "B", there will be 18 Conductors, and all 18 will carry FULL LOAD AMPERES, per the connected Loads.
If Loads are Non-Linear and "Noisy", the Common Star Point Grounded Conductor will carry the highest Load Amperes, along with 2x the distorted Load Amperes.
Example "B" has no "Balancing Neutral High-Wire Circus Act"

-- Scott

Scott- Thanks for your very detailed explanation of the problem. The OP was meant to convey that the circuits were not multi-wire. The contractor was somehow confused into thinking that he didn't need to count the neutrals as CCC's. I tried to explain it to him but to no avail. To add to what you were saying, The Delta system is the only system that you can run a Multi-wire circuit consisting of two phase wires on opposite phases and a common conductor and not have count the common (neutral) conductor as a CCC. If you have a Wye and you have a multi-wire circuit consisting of two phase wires and a common conductor you can't get away with that because of the phase relationship is not 180 degrees apart. Now if you have all three phase wires sharing a common neutral and it's not a linear load you still have to count the neutral as a CCC.

Boils down to the phase relationship.

Interestingly, if it's a Delta feeder or Service you might be able to not count the common conductor as a CCC but be aware you still count it for raceway fill.

Just another George question that went ballistic :))

Back to you Scott