CET ELEC.11 Using Wire Tables and Determining Conductor Sizes

Name five conditions that must be met for running conductors in parallel.

1. Be the same length 2. Be the same conductor material 3. Be the same size in circular mil area 4. Have the same insulation type 5. Be terminated in the same manner

What is the largest solid (nonstranded) conductor listed in the wire tables?

10 AWG

Twenty-five 12 AWG copper conductors are run in conduit. Each conductor has Type THHN insulation. The conduit is located in an area that has an ambient temperature of 95ºF. What is the ampacity of each conductor.

12.96 amps

A three-phase motor operates on 480 V and is located 1800 ft from the power source. The starting current is 235 A. What size copper conductors will be needed to supply this load if the voltage must not be permitted to drop below 6% of the terminal voltage during starting?

300 kcmil cable.

A 10 AWG copper conductor with Type THW insulation is to be run in free air. What is the maximum ampacity of this conductor if the ambient air temperature is 40ºC?

44 amps

What is the maximum temperature rating of Type XHHW insulation when used in a wet location?

75ºC or 167ºF

Six 1/0 aluminum conductors are to be run in a conduit. Each conductor has Type THWN insulation, and the ambient air temperature is 30ºC. What is the ampacity of each conductor?

96 amps

How is the grounded conductor in a flat multiconductor cable 4 or larger identified?

External ridge

Can type TW cable be used in an area that has an ambient temperature of 65ºC?

No.

Name two types of conductor insulation designed to be used underground.

UF and USE

What three colors are ungrounded conductors not permitted to be?

White, gray or green