Specific Equipment Part III

$ 29.00

Continuing Education Units (CEU): 0.10

Expected Duration: 1 Hour

This self-paced online course is the third of three covering specific equipment addressed in Chapter 4 of the NEC. Chapter 4, titled "Equipment for General Use," covers a very broad range of equipment.

Upon completion you should be able to:

  • Identify some of the most commonly applied articles of NEC Chapter 4.
  • For motors, motor circuits and controllers:
    • Explain how motor requirements are different from general requirements.
    • Identify requirements for motor location, disconnecting means and sizing of conductors and equipment.
  • For air conditioning and refrigeration equipment:
    • Explain how Articles 430 and 440 are similar and how they are different.
    • Explain what replaces horsepower ratings in Article 440.
    • Identify nameplate requirements, overload protection and disconnecting means.
  • For transformers and transformer vaults:
    • Identify requirements for overcurrent protection, ventilation, accessibility and disconnecting means.
    • Explain the difference between requirements for transformers rated at different power levels

Who Will Benefit

Anyone whose job involves designing, reviewing, evaluating or installing fire protection systems, including: designers, installers, engineers, electrical contractors, technicians, project managers, fire marshals, and architects.

Course Summary

  • Requirements for motors, motor circuits and controllers are covered in Article 430. Many requirements for motors are very different from the NEC's general rules.
  • Table values are used for sizing everything but the overload protection, which is sized according to the nameplate value. However, if the nameplate value is higher than the table value, the nameplate value is used for sizing all components of the circuit.
  • Article 440 addresses motor driven air-conditioning and refrigeration equipment. Articles 440 and 430 are almost identical, except that Article 440 does not include horsepower ratings, which are the basis for nearly everything in Article 430. Instead, the rating will be the larger of either the rated load current or the branch circuit selection current.
  • Article 450 covers transformers, primarily those that are used for power distribution or power conditioning.
  • Transformers require enough ventilation to dispose of the transformer's full load losses without creating a temperature rise in excess of the transformer's rating.
  • Transformers must be accessible but not always readily accessible and must have a disconnecting means located either in sight of the transformer or in a remote location with the remote location noted on the transformer.
  • Requirements are slightly different for transformers up to 112.5 KVA and those over 112.5 KVA. There are special containment requirements for transformers over 35,000 volts.