Conductor Properties
Ampacity & Derating
Box & Wireway Fill
Calculations & Voltage Drop
NEC Code & Definitions
100

How much larger is the diameter of a 10 AWG stranded conductor than that of a 10 AWG solid conductor?

What is 0.014 in.? (Ref: Q1)

100

The ampacity of three 2/0 AWG THW Aluminum conductors installed in RMC in an 86°F ambient temperature...

What is 135 A? (Ref: Q8)

100

The minimum box volume for a box containing four 12 AWG conductors, a receptacle, an equipment grounding conductor, and internal cable clamps...

What is 18 cubic inches? (Ref: Q25)

100

When a branch circuit minimum ampacity calculation results in a value of 25.45, this is the minimum standard branch circuit size permitted when rounding...

What is 25 Amperes? (Ref: Q23)

100

The term defined as a point on the wiring system at which current is taken to supply utilization equipment...

What is an outlet? (Ref: Q10)

200

The circular mil area of a bare 2 AWG copper conductor is approximately...

What is 0.067 in.²? (Ref: Q5)

200

The terminal ampacity when an ungrounded 500 kcmil THHN aluminum conductor is connected to a 400A rated circuit breaker...

What is 310 A? (Ref: Q17)

200

The size Schedule 40 Rigid PVC required if it contains two 12/3 NM cables (width = 524 mils, height = 190 mils)...

What is 1-1/4 inch PVC? (Ref: Q9)

200

The minimum standard size inverse-time circuit breaker required for a 480V, 3-phase circuit supplying a 60 kW continuous load and a 20 kW non-continuous load...

What is a 125 Amp breaker? (Ref: Q4)

200

The specific National Electrical Code section that clearly prohibits exceeding the maximum operating temperature of an insulated conductor...

What is NEC Section 310.14(A)(3)? (Ref: Q14)

300

Chapter 9 tables that apply to single insulated conductors in free air where heat is easily dissipated...

What is Table 310.17? (Ref: Q16)

300

The ampacity of each of twenty 12 AWG THHN copper conductors installed in the same metal wireway as twenty-one 6 AWG THHN copper conductors at 30°C...

What is 10.5 A? (Ref: Q12)

300

In a 4 in. x 4 in. metal wireway containing twenty-four 6 AWG THW conductors, the number of 3 AWG THHN conductors that can be added without exceeding wire fill...

What is 14 conductors? (Ref: Q3)

300

The minimum size aluminum wire needed for a 440V, single-phase branch circuit supplying a 60A load at a distance of 425 feet, holding voltage drop to 13.2V...

What is 1 AWG aluminum? (Ref: Q13)

300

When applying derating provisions to a 4-wire, 3-phase wye system, this type of load requires the neutral to be counted as a current-carrying conductor...

What is a non-linear load? (Ref: Q6)

400

The DC resistance of 500 feet of 500,000 circular mils uncoated copper, rounded to four decimal places...

What is 0.0129 ohms? (Ref: Q19)

400

The minimum size copper THW ungrounded service-entrance conductors required for a single-family dwelling with a calculated load of 120A on a 120/240V system...

What is 2 AWG? (Ref: Q18)

400

The percentage fill permitted for a conduit nipple up to 24 inches in length...

What is 60%? (Ref: Q22)

400

The voltage drop on a single-phase, 460V branch circuit supplying a 175A load at 197 feet using 3/0 AWG THWN copper conductors...

What is 5.28 V? (Ref: Q24 / Q27)

400

When installing a 10-3 SE cable with RHW insulation in direct contact with thermal insulation, this is its ampacity...

What is 30 A? (Ref: Q7)

500

The principle often used to determine the temperature rating of an entire circuit based on its most restrictive component...

What is the principle of the weakest link? (Ref: Q21)

500

The minimum size THWN-2 grounded feeder conductor required for an individual dwelling unit with a 125A panelboard and a neutral load calculated at 90A...

What is 3 AWG? (Ref: Q15)

500

 : In residential or commercial box calculations, a yoke containing two devices counts as this equivalent number of conductor volumes...

What is 2 conductor volumes? (Ref: Q2 box calculation principles)

500

From a practical point of view, after continuous and non-continuous loads are calculated, the size of this component should be determined first and the conductor selected second...

What is the overcurrent protective device (OCPD)? (Ref: Q11)

500

Two 2-wire 120V circuits sharing a neutral in a 120/240V system require their neutral to be counted as this under Table 310.15(C)(1)...

What is a current-carrying conductor? (Ref: Q6 variant)