HoseB611,
Can you give us more information on how this voltage drop rule is enforced or evaluated? Is it an amendment written into the code? Or an inspector enforcing the FPN that has been in the code for ages?
Do they mandate no more than 5% VD at the trip rating of the circuit? Or at the expected load on the circuit? How are short duration overloads (motor starting) evaluated. Must the circuit be sized sufficiently to start a large motor without 5% drop?
IMHO there is already an implied voltage drop requirement in the code, as a result of the 'effective ground fault current path' requirement. Soares interprets this as meaning that a short circuit must cause sufficient current flow to reach the 'instantaneous trip' range of the breaker. This means that at the end of the circuit, you want about 8-10x the trip rating of the breaker, implying a maximum voltage drop at the trip rating of about 10%.
-Jon
