IEC Basic Electrical Standards 3

Question 1

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

Accepted Answer

Flexible cords may never substitute for fixed wiring

Answer

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

Question 2

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

Accepted Answer

Working space clearances of 36 inches depth must be maintained

Answer

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

Question 3

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

Accepted Answer

By using different insulation colors or permanent identification marks

Answer

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

Question 4

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

Accepted Answer

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

Answer

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

Question 5

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

Accepted Answer

Liquidtight flexible nonmetallic conduit without a listed fitting

Answer

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

IEC - Independent Electrical Contractors Practice Test