frank osuna
Member
- Location
- New Mexico
When applying 2002 NEC Article 520, to performance theater stage lighting, where the number of conductors in a raceway exceeds 30: Paragraph 520.6 headlines "Number of Conductors in Raceway". 520.6 goes on to specify that the stage lighting branch circuits be sized for voltage drop. And indicates deration for number of conductors exceeding 30 by Article 310.15(B)(2)(a) is not required by exclusion of 366.6 (applicable to auxillary gutters) and 376.22 (applicable to wireways).
In my theater under construction I have a wireway at the catwalk level with (10)4" conduits down to the dimmer rack 20 feet below. The wire count is 216 phase, 216 neutral, 23 grounds for a total of 480 conductors. The wireway fill is 9%. By the NEC paragraphs above the conductors are not required to be derated due to number of conductors. And because the distance does not exceed voltage drop requirements the conductor does not need de-rating for voltage drop either. Fill on the 4? conduits (raceway) is 11%. But the wording of the code does not specifically state the exception to the wireway can be applied to the conduit (raceway). The only way it seems to apply its intent is that the Heading of 520.6 says RACEWAY. To me it appears an oversight in the code. I think I can win the argument with the inspector is if I can convince him that heat dissipation in conduit (raceway) is the same as heat dissipation in wireway. Do you believe that to be true?
In my theater under construction I have a wireway at the catwalk level with (10)4" conduits down to the dimmer rack 20 feet below. The wire count is 216 phase, 216 neutral, 23 grounds for a total of 480 conductors. The wireway fill is 9%. By the NEC paragraphs above the conductors are not required to be derated due to number of conductors. And because the distance does not exceed voltage drop requirements the conductor does not need de-rating for voltage drop either. Fill on the 4? conduits (raceway) is 11%. But the wording of the code does not specifically state the exception to the wireway can be applied to the conduit (raceway). The only way it seems to apply its intent is that the Heading of 520.6 says RACEWAY. To me it appears an oversight in the code. I think I can win the argument with the inspector is if I can convince him that heat dissipation in conduit (raceway) is the same as heat dissipation in wireway. Do you believe that to be true?