Services & DistributionQuestion 21 of 521
For equipment terminals on a circuit rated 100 A or less (not marked otherwise), which temperature column must be used to size conductors?
a.90 C column
b.The highest column of the conductor insulation
c.75 C column always
d.60 C column
Explanation
Per 110.14(C)(1), for circuits rated 100 A or less or 14-1 AWG conductors, terminations are limited to the 60 C column unless the equipment is listed for higher. The 90 C column may be used only for correction/adjustment, never for final termination sizing.
Law Reference: 2023 NEC §110.14(C)Practice all 521 questions free — no signup required.
Related questions on this topic
- A 4/0 AWG copper THHN conductor (90 C, base 260 A) is in an ambient of 45 C. Using the 0.87 correction factor, what is the corrected ampacity?
- Six current-carrying conductors are installed in a single raceway. What adjustment factor applies to their ampacity?
- How many current-carrying conductors can be in a raceway before an adjustment (fill derating) factor must be applied?
- A feeder supplies a continuous load of 176 A. What minimum conductor ampacity (before derating) is required?
- Six 3 AWG THHN copper conductors (90 C ampacity 110 A) are in one raceway at 30 C ambient. After the fill adjustment, what is the derated ampacity?
- Using the 60 C column of Table 310.16, what is the ampacity of a 6 AWG copper conductor?
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