Question 1
A device box already contains two insulated conductors and one bonding conductor. You plan to add another cable with two insulated conductors and one bonding conductor. What is the main concern when deciding whether this box is acceptable?
Question 2
When calculating box fill, what does each insulated conductor that originates outside and terminates or is spliced inside the box typically count as?
Question 3
An electrician installs several cables into a small device box and finds it very crowded. What is the main concern with overfilling a device box?
Question 4
Which item must be counted when calculating box fill for a device box containing splices?
Question 5
When adding additional conductors to an existing device box, which factor is most important to check before making the splice?
Question 6
A device box contains two cable runs of NMD with two insulated conductors and one bonding conductor in each cable, plus one duplex receptacle. Which factor most affects whether the box size is adequate?
Question 7
Why must outlet boxes not be overfilled with conductors and devices?
Question 8
Why is it poor practice to leave long conductors tightly coiled inside a device box?
Question 9
In a junction box, three 14/2 NMD90 cables are joined together. Which factor primarily determines whether the box is large enough?
Question 10
What is a potential result of overcrowding conductors in a device box beyond its allowable fill capacity?
Question 11
A device box contains two 14/2 cables (hot, neutral, bonding in each) and one 14/3 cable (two hots, neutral, bonding). Which concern must the electrician address regarding box fill?
Question 12
A 4 in square box contains four 12 AWG insulated conductors, one 12 AWG equipment grounding conductor, and one internal clamp. If each 12 AWG conductor requires 2.25 in³ of volume, how many conductor equivalents must be counted for box fill?
Question 13
An apprentice must size a box for four 12 AWG conductors plus a device. Why is box fill important?
Question 14
When installing conductors in a box, why is box fill calculation important?
Question 15
For box fill calculations, how is a standard device such as a single-pole switch counted?
Question 16
A 4-inch square metal box contains four 12 AWG insulated conductors (two hots, one neutral, one traveler), one 12 AWG equipment grounding conductor, and one single-pole switch. For box fill, how many 12 AWG conductor volumes must be counted?
Question 17
A junction box contains four 12 AWG insulated copper conductors and two 12 AWG equipment grounding conductors spliced together. Ignoring device allowances, approximately how many conductor 'equivalents' should be counted for box fill?
Question 18
A junction box in a fire-rated wall has several cables entering and exiting. Why must the electrician seal around the box and cables as required by the building design?
Question 19
A device box contains three 14 AWG NM cables: one feed, one load, and one cable to a switch. Each cable has a hot, neutral, and ground. The grounds are spliced with a pigtail to the device. Ignoring internal clamps and devices, approximately how many 14 AWG conductor 'equivalents' are counted for box fill?
Question 20
You must calculate the box fill for a 4 in square box with a device yoke and several conductors. Why is box fill important?
Question 21
A device box contains two 14/2 NM cables (each with a hot and neutral plus grounds spliced together). What is one important factor to consider when choosing the box?
Question 22
Why is it important to calculate box fill when installing conductors in a device box?
Question 23
A plastic device box will contain three 14 AWG insulated conductors, one duplex receptacle, and an internal cable clamp. If each 14 AWG conductor is counted as 2.0 in³ for box fill, what is the MINIMUM volume required for this box?
Question 24
Why is box fill calculation important when installing conductors in a junction box?
Question 25
A junction box contains four 12 AWG insulated conductors (hot and neutral in and out) and one 12 AWG equipment grounding conductor. Ignoring any device yokes, how many conductor volume equivalents must be counted for box fill?
Question 26
When installing conductors in a junction box, which factor is most important in determining the maximum number of conductors allowed?
Question 27
A feeder supplies a subpanel located 150 feet away. What is the most practical reason to increase the conductor size beyond minimum ampacity?
Question 28
When calculating box fill, which of the following items must be counted toward conductor fill volume?
Question 29
When calculating conductor fill for a device box, which of the following groups must all be counted toward the box volume allowance?
Question 30
A junction box contains four 12 AWG current-carrying conductors and two 12 AWG equipment grounding conductors. If one conductor of each type enters and leaves the box, how many 12 AWG conductor equivalents should be counted for box fill calculation purposes?
