CEA Wiring Methods & Installation Practices 3

Question 1

What is the minimum wire fill percentage allowed in a conduit according to NEC Chapter 9 for three or more conductors?

Accepted Answer

31%

Answer

For three or more conductors, NEC Chapter 9 allows a maximum conduit fill of 40%, but the standard fill for three or more conductors is 40% not to exceed.

Question 2

Which type of conduit fitting is required when connecting RMC to an enclosure to maintain a grounding path?

Accepted Answer

Bonding locknut or bonding bushing

Answer

A bonding locknut or bonding bushing is required where a reliable grounding path must be maintained at RMC enclosure connections.

Question 3

What is the maximum spacing between supports for 1-inch EMT installed horizontally?

Accepted Answer

10 feet

Answer

EMT 1 inch and larger must be supported at intervals not exceeding 10 feet when installed horizontally.

Question 4

Underground feeder cable (Type UF) used as interior wiring must comply with which wiring method requirements?

Accepted Answer

UF cable used inside must comply with NM cable rules

Answer

When Type UF cable is used inside a building, it must be installed in the same manner as Type NM cable per NEC requirements.

Question 5

Where must expansion fittings be installed in a PVC conduit run?

Accepted Answer

Where the conduit crosses building expansion joints or where thermal expansion exceeds conduit's flexibility

Answer

Expansion fittings must be installed where conduit crosses building expansion joints or where significant thermal expansion would stress the conduit system.

(CEA) Certified Electrical Apprentice Practice Test

(CEA) Certified Electrical Apprentice Practice Test

CEA Wiring Methods & Installation Practices 3