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Don Y[_3_]

On 2/5/2016 5:59 PM, wrote:

On Fri, 05 Feb 2016 14:15:30 -0700, Don Y
wrote:

I know that one very long run
to the kitchen reads 105 volts with the microwave on when the voltage at the
breaker serving that run is at 119 volts. This is a run that has been used,
apparently, for years with a 20A breaker even though the wire apparently is
only 14 gauge. We will be correcting that by wiring it to a 15A breaker

frown Sure to get flagged by an inspection. For "efficiency", you
typically only want a 3-5% voltage drop under load. Wire is "sized" so
the heat generated in the conductor is safe for the insulation chosen
(the wire won't melt but the insulation will degrade).

Maybe in a state that has amended an energy code into the NEC but that
3%/5% is just an informational note, not enforceable code.

I didn't say the efficiency aspect would get flagged. Rather, that
a 14AWG conductor was fused at 20A. The efficiency note is intended
to explain why the 14V drop is Not A Good Thing. The wire sizing
and insulation note is to explain why a wire is sized for a particular
ampacity.