Basic Electrical Standards Flashcards

What is the maximum length of a flexible cord used as a substitute for fixed wiring in a dwelling?

Answer: Flexible cords may never substitute for fixed wiring

NEC 400.12 prohibits flexible cords from being used as a substitute for fixed wiring of a structure.

When installing a panelboard in a residential garage, what NEC requirement applies?

Answer: Working space clearances of 36 inches depth must be maintained

NEC 110.26 requires a minimum of 36 inches of clear working space in front of electrical panels.

Under the NEC, how must conductors of different systems (e.g., 120V and 277V) be identified when in the same enclosure?

Answer: By using different insulation colors or permanent identification marks

NEC 210.5 requires conductors of different systems to be identified by color or other permanent means.

What is the required ampacity of the main bonding jumper at the service for a 200-ampere service?

Answer: It must be sized per NEC Table 250.66 based on service conductor size

NEC 250.28 requires main bonding jumpers to be sized per Table 250.66, based on the service-entrance conductor size.

Which of the following is NOT a permitted wiring method for a residential attic installation?

Answer: Liquidtight flexible nonmetallic conduit without a listed fitting

All fittings used with liquidtight flexible conduit must be listed, making improper fittings a code violation.

A disconnect means for a motor must be located within sight of the motor unless which condition is met?

Answer: The disconnect is lockable in the open position

NEC 430.102(B) allows the disconnect to be out of sight if it can be locked in the open (off) position.

Per the NEC, what is the maximum number of overcurrent devices permitted in a lighting and appliance branch-circuit panelboard?

Answer: 42

NEC 408.36 limits lighting and appliance branch-circuit panelboards to a maximum of 42 overcurrent devices.