Free NEC Equipment for General Use Questions and Answers — Questions and Answers
Question 1: An electrician is replacing a two-wire, non-grounding-type receptacle in a location where no equipment grounding conductor exists in the outlet box. Which of the following is NOT a permitted replacement according to NEC 406.4(D)?
- A new non-grounding-type receptacle.
- A standard grounding-type receptacle connected to the grounded (neutral) conductor via a jumper. (Correct answer)
- A GFCI-type receptacle marked 'No Equipment Ground.'
- A standard grounding-type receptacle protected by an upstream GFCI device, with the receptacle marked 'GFCI Protected' and 'No Equipment Ground.'
Correct answer: A standard grounding-type receptacle connected to the grounded (neutral) conductor via a jumper.
NEC 406.4(D) provides several options for replacing a non-grounding receptacle where no equipment grounding conductor exists, including another non-grounding receptacle or a GFCI-protected option. However, using a jumper to connect the grounding terminal to the neutral conductor (a 'bootleg ground') is a dangerous code violation as it can energize the equipment's metal housing if the neutral path is broken.
Question 2: What is the maximum weight for a luminaire that is permitted to be supported solely by a standard outlet box, unless the box is specifically listed and marked for a greater weight?
- 25 lbs
- 35 lbs
- 50 lbs (Correct answer)
- 70 lbs
Correct answer: 50 lbs
According to NEC 410.36(A) and 314.27(A)(2), outlet boxes or fittings used to support luminaires are generally limited to supporting a maximum weight of 23 kg (50 lb). If a luminaire weighs more than 50 lbs, it must be supported independently of the outlet box unless the box is listed for the specific weight.
Question 3: A 5 kW electric water heater is installed in a closet. The circuit breaker for the water heater is in a panelboard located down the hall and is not within sight of the appliance. To comply with NEC Article 422, what is required for the circuit breaker to serve as the disconnecting means?
- It must be labeled 'Water Heater Disconnect.'
- It must be a GFCI type breaker.
- It must be capable of being locked in the open position. (Correct answer)
- It must be rated at least 150% of the appliance load.
Correct answer: It must be capable of being locked in the open position.
NEC 422.31(B) states that for a permanently connected appliance rated over 300 VA, the branch-circuit overcurrent device (breaker) can be the disconnecting means. If the breaker is not within sight of the appliance, it must be capable of being locked in the open position to ensure safety during service.
Question 4: According to the NEC, a motor's disconnecting means must generally be located 'in sight from' the motor's location. What is the definition of 'In Sight From'?
- Visible and not more than 25 feet distant from the other.
- Located on the same wall and within the same room as the other.
- Accessible on the same floor level and within 100 feet of the other.
- Visible and not more than 50 feet distant from the other. (Correct answer)
Correct answer: Visible and not more than 50 feet distant from the other.
The definition of 'In Sight From (Within Sight From, Within Sight)' is found in NEC Article 100. It specifies that the equipment must be visible and not more than 50 feet (15 m) distant from the other. This rule is applied in sections like 430.102(B) to ensure a worker can see the disconnecting means while working on the motor.
Question 5: An electrician is remodeling a bathroom and must install a new lighting switch. According to NEC 404.4(C), in which of the following locations is a switch NOT permitted to be installed?
- Within the tub or shower space. (Correct answer)
- On the wall, 3 feet horizontally from the tub's edge.
- Above the vanity countertop.
- Adjacent to the entry door.
Correct answer: Within the tub or shower space.
NEC 404.4(C) explicitly prohibits installing switches within the wet location of tub or shower spaces unless they are part of a listed tub or shower assembly. This rule is in place to prevent a person from touching a switch while in contact with water, reducing the risk of severe electric shock.
Question 6: According to NEC Article 408, every circuit in a panelboard must be legibly identified as to its specific purpose. Which of the following directory entries would be considered NON-COMPLIANT for a circuit breaker position that has no breaker or wiring installed?
- Kitchen Counter Receptacles
- Future Use (Correct answer)
- Master Bedroom Lights
- Garage Door Opener
Correct answer: Future Use
NEC 408.4(A) requires identification for each circuit to be clear and specific. While positions with unused overcurrent devices should be marked 'Spare,' the term 'Future Use' is not permitted because it is not specific. The intent is to clearly identify the purpose of every active or potentially active circuit position.
Free NEC Equipment for General Use Questions and Answers
An electrician is replacing a two-wire, non-grounding-type receptacle in a location where no equipment grounding conductor exists in the outlet box.
Which of the following is NOT a permitted replacement according to NEC 406.4(D)?