Motors & EquipmentQuestion 96 of 120
An air conditioning condensing unit nameplate reads minimum circuit ampacity 24.6 and maximum overcurrent protective device 40. What overcurrent device must be installed?
a.A 30-ampere device, the next standard size above the minimum circuit ampacity
b.A 25-ampere device to match the minimum circuit ampacity
c.A 50-ampere device sized at 125 percent of the marked maximum
d.A device not exceeding 40 amperes
Explanation
The marked maximum overcurrent protective device value is a ceiling set by the equipment manufacturer and tested with the unit, so the installed device must not exceed 40 amperes; a smaller device is acceptable only if it will carry the starting current. The minimum circuit ampacity of 24.6 sizes the conductors, not the protective device, and nothing permits multiplying the marked maximum by another factor.
Law Reference: 2023 NEC §440.4(B)Practice all 120 questions free — no signup required.
Related questions on this topic
- A continuous-duty motor over 1 horsepower is marked with a temperature rise of 40 degrees C but no service factor. What percentage of nameplate full-load current sets the maximum overload device?
- A continuous-duty motor over 1 horsepower has no marked service factor and no marked temperature rise. What is the maximum overload device rating as a percentage of nameplate full-load current?
- Where must a motor disconnecting means be located relative to the motor?
- A hermetic refrigerant motor-compressor has a rated-load current of 20 amperes. What is the maximum branch-circuit short-circuit and ground-fault protective device at the standard 175 percent figure?
- For that same 20-ampere rated-load compressor supplied alone, what minimum conductor ampacity is required?
- A surface-mounted luminaire with a completely enclosed light source is installed in a clothes closet. What is the minimum clearance to the nearest point of the defined storage space?
Last reviewed: · editorial process
PrepPass Editorial Team · Verified against Journeyman Electrician Licensing Exam (NEC-based) · How we review