CSLB General Building (B) — All Questions

Using NEC Table 430.250, what is the full-load current (FLC) of a 10 HP, three-phase, 460-volt squirrel-cage motor?

• a.14 A✓
• b.28 A
• c.21 A
• d.11 A

NEC Table 430.250 lists 14 A for a 10 HP 460 V three-phase motor; these table values (not nameplate amps) are used for conductor and overcurrent sizing. 28 A is the 230 V value, 21 A is a 15 HP motor, and 11 A is 7.5 HP at 460 V.2023 NEC Table 430.250

Per NEC Table 430.248, what is the full-load current of a 5 HP, single-phase, 230-volt motor?

• a.56 A
• b.28 A✓
• c.17 A
• d.40 A

Table 430.248 gives 28 A for a 5 HP single-phase 230 V motor. 56 A is the 115 V value for the same HP, 17 A is a 3 HP 230 V single-phase motor, and 40 A is a 7.5 HP 230 V motor.2023 NEC Table 430.248

A single continuous-duty 25 HP, 460 V, three-phase motor has an FLC of 34 A (Table 430.250). What minimum conductor ampacity is required for its branch circuit?

• a.34 A
• b.38.25 A
• c.42.5 A✓
• d.46.75 A

NEC 430.22 requires branch-circuit conductors for a single continuous-duty motor to be sized at 125% of FLC: 34 A x 1.25 = 42.5 A. 34 A ignores the 125% factor, 38.25 A uses 112.5%, and 46.75 A uses 137.5%.2023 NEC §430.22

A motor's nameplate shows a full-load current of 40 A and a service factor of 1.15. Under NEC 430.32(A)(1), what is the maximum overload device rating at 125% of nameplate FLA?

• a.40 A
• b.44 A
• c.46 A
• d.50 A✓

For a motor with a marked service factor of 1.15 or greater, 430.32(A)(1) permits overload protection up to 125% of the nameplate FLA: 40 x 1.25 = 50 A. 44 A is 110%, 46 A is 115% (used only for other motors), and 40 A applies no multiplier.2023 NEC §430.32

For a 20 HP, 460 V, three-phase motor (FLC 27 A), what is the maximum inverse-time circuit breaker rating for branch-circuit short-circuit and ground-fault protection, using the 250% value of Table 430.52?

• a.67.5 A✓
• b.47.25 A
• c.81 A
• d.54 A

Table 430.52 allows an inverse-time breaker at 250% of FLC: 27 x 2.50 = 67.5 A (then the next-standard-size rule of 430.52(C)(1) Ex. may apply). 47.25 A is 175% (dual-element fuse), 81 A is 300% (nontime-delay fuse), and 54 A is 200%.2023 NEC §430.52

Using the same 20 HP, 460 V motor (FLC 27 A), what is the maximum dual-element (time-delay) fuse permitted by Table 430.52 for branch-circuit short-circuit and ground-fault protection?

• a.67.5 A
• b.47.25 A✓
• c.81 A
• d.33.75 A

Table 430.52 permits a dual-element time-delay fuse at 175% of FLC: 27 x 1.75 = 47.25 A. 67.5 A is 250% (inverse-time breaker), 81 A is 300% (nontime-delay fuse), and 33.75 A is 125%.2023 NEC §430.52

A 5 HP, 230 V, three-phase motor has an FLC of 15.2 A. What is the maximum nontime-delay fuse permitted by Table 430.52 for branch-circuit protection?

• a.26.6 A
• b.38 A
• c.45.6 A✓
• d.121.6 A

A nontime-delay fuse may be sized up to 300% of FLC: 15.2 x 3.00 = 45.6 A. 26.6 A is 175% (dual-element fuse), 38 A is 250% (inverse-time breaker), and 121.6 A is 800% (instantaneous-trip breaker).2023 NEC §430.52

For the same 5 HP, 230 V motor (FLC 15.2 A), what is the maximum instantaneous-trip circuit breaker setting permitted by Table 430.52?

• a.45.6 A
• b.38 A
• c.76 A
• d.121.6 A✓

Table 430.52 permits an instantaneous-trip breaker up to 800% of FLC for most motors: 15.2 x 8 = 121.6 A. 45.6 A is 300%, 38 A is 250%, and 76 A is 500%.2023 NEC §430.52

When sizing branch-circuit conductors and short-circuit/ground-fault protection for a standard motor, which current value does the NEC require you to use?

• a.The full-load current from Tables 430.247 through 430.250✓
• b.The nameplate full-load amperes
• c.The locked-rotor current
• d.The service-factor amperes

NEC 430.6(A)(1) requires the table FLC values (430.247-430.250) for conductor and branch-circuit protection sizing. The nameplate FLA is used only for overload (running) protection, while locked-rotor and service-factor amps serve other purposes.2023 NEC §430.6

Which motor current rating is used to select the running overload (overcurrent) protection device?

• a.The Table 430.250 full-load current
• b.The motor nameplate full-load amperes✓
• c.The locked-rotor current from Table 430.251
• d.250% of the full-load current

NEC 430.6(A)(2) and 430.32 base overload protection on the motor's nameplate full-load amperes, because overloads protect the actual motor. The table FLC is used for conductors and short-circuit protection, not overload sizing.2023 NEC §430.32

A motor nameplate reads 28 A full-load, service factor 1.0, temperature rise not marked. What is the maximum overload rating under NEC 430.32(A)(1)?

• a.28 A
• b.35 A
• c.32.2 A✓
• d.30.8 A

Motors without a 1.15+ service factor or a 40C-or-less marked temperature rise are limited to 115% of nameplate FLA: 28 x 1.15 = 32.2 A. 125% (35 A) applies only to SF >=1.15 or <=40C-rise motors, and 30.8 A is 110%.2023 NEC §430.32

A feeder supplies two three-phase, 460 V motors: 20 HP (FLC 27 A) and 10 HP (FLC 14 A). Per NEC 430.24, what minimum feeder conductor ampacity is required?

• a.41 A
• b.51.25 A
• c.54 A
• d.47.75 A✓

NEC 430.24 requires 125% of the largest motor's FLC plus the sum of the others: (27 x 1.25) + 14 = 33.75 + 14 = 47.75 A. 41 A omits the 125% factor, 51.25 A applies 125% to both, and 54 A doubles the largest.2023 NEC §430.24

A motor disconnecting means must have an ampere rating at least 115% of the motor FLC. For a 15 HP, 460 V, three-phase motor (FLC 21 A), what is the minimum disconnect ampere rating?

• a.24.15 A✓
• b.21 A
• c.26.25 A
• d.18.9 A

NEC 430.110(A) requires the disconnecting means to be rated at least 115% of the FLC: 21 x 1.15 = 24.15 A. 21 A ignores the 115% factor, 26.25 A is 125%, and 18.9 A is 90%.2023 NEC §430.110

In a motor installation, what is the primary function of the motor controller?

• a.To provide short-circuit and ground-fault protection
• b.To start and stop the motor by connecting and disconnecting it from the power source✓
• c.To protect conductors from overload only
• d.To serve as the required disconnecting means for maintenance

NEC Article 430 Part VII defines the controller as the device that starts and stops the motor by making and breaking the motor-circuit current. Short-circuit protection, overload protection, and the disconnecting means are separate required elements, though one device can sometimes serve more than one role.2023 NEC §430.81

A motor control circuit tapped from the load side of the motor branch-circuit protection is generally protected against overcurrent according to which NEC provision?

• a.Article 240 only
• b.Table 430.52
• c.NEC 430.72 (motor control circuits)✓
• d.Article 450

NEC 430.72 and Table 430.72(B) govern overcurrent protection of motor control circuit conductors, including tapped control conductors. Table 430.52 covers motor branch-circuit (power) protection, Article 240 covers general circuits, and Article 450 covers transformers.2023 NEC §430.72

A single hermetic refrigerant motor-compressor has a rated-load current of 24 A. Per NEC 440.32, what minimum branch-circuit conductor ampacity is required?

• a.24 A
• b.26 A
• c.28.8 A
• d.30 A✓

NEC 440.32 requires conductors for a single motor-compressor to be sized at 125% of the rated-load current or branch-circuit selection current, whichever is larger: 24 x 1.25 = 30 A. 24 A omits the factor, 26 A is ~108%, and 28.8 A is 120%.2023 NEC §440.32

On an air-conditioning unit nameplate, what does the 'Minimum Circuit Ampacity (MCA)' value tell the installer?

• a.The minimum ampacity the branch-circuit conductors must have✓
• b.The maximum fuse or breaker size allowed
• c.The full-load current of the condenser fan only
• d.The locked-rotor current of the compressor

MCA is the minimum conductor ampacity required to supply the unit, already calculated by the manufacturer (125% of the largest motor plus other loads). The maximum overcurrent device is the separate MOCP/'Max Fuse' value; MCA is not a fan rating or locked-rotor value.2023 NEC §440.4

The 'Maximum Overcurrent Protective Device' (MOCP or 'Max Fuse/HACR Breaker') rating on an HVAC nameplate specifies what?

• a.The smallest breaker that will start the unit
• b.The largest fuse or circuit breaker permitted to protect the branch circuit✓
• c.The required conductor size
• d.The disconnect switch rating only

The MOCP is the maximum size of fuse or HACR-rated breaker allowed for the unit's branch circuit; you may install this size or smaller, but not larger. MCA sets the conductor ampacity; the two values are used together per 440.4(B).2023 NEC §440.4

An A/C condensing unit has a compressor rated-load current of 18 A and a fan motor of 2 A. Using the 125%-of-largest-motor-plus-others method, what is the minimum circuit ampacity (MCA)?

• a.20 A
• b.25 A
• c.24.5 A✓
• d.27.5 A

MCA = 125% of the largest motor + sum of the other loads: (18 x 1.25) + 2 = 22.5 + 2 = 24.5 A. 20 A omits the 125% factor, 25 A applies 125% to the whole 20 A, and 27.5 A applies 125% to both loads.2023 NEC §440.33

For a hermetic motor-compressor with a rated-load current of 18 A, what is the maximum branch-circuit short-circuit/ground-fault protective device, based on the 175% value of NEC 440.22(A)?

• a.22.5 A
• b.27 A
• c.40.5 A
• d.31.5 A✓

NEC 440.22(A) sizes the protective device at not more than 175% of the rated-load (or branch-circuit selection) current: 18 x 1.75 = 31.5 A. 22.5 A is 125% (conductor factor), 27 A is 150%, and 40.5 A is 225% (the absolute maximum only where needed to start).2023 NEC §440.22

If a motor-compressor (rated-load 18 A) will not start on the 175% device, NEC 440.22(A) permits increasing the protection to a maximum of what value?

• a.225% = 40.5 A✓
• b.200% = 36 A
• c.250% = 45 A
• d.300% = 54 A

NEC 440.22(A) allows an increase up to 225% of the rated-load current where the 175% device will not carry starting current: 18 x 2.25 = 40.5 A. 200%, 250%, and 300% are not the permitted ceilings for hermetic-compressor branch-circuit protection.2023 NEC §440.22

A 30 kVA, three-phase transformer has a 480 V primary (primary current ~36 A). With primary-only protection and no supervised condition, what is the maximum primary overcurrent device using the 125% factor of Table 450.3(B)?

• a.36 A
• b.45 A✓
• c.60 A
• d.72 A

For a transformer with primary current of 9 A or more, Table 450.3(B) limits primary-only protection to 125%: 36 x 1.25 = 45 A (with the note allowing the next standard size where 125% does not correspond). 36 A omits the factor, 60 A is ~167%, and 72 A is 200%.2023 NEC §450.3

NEC 450.3(B) overcurrent protection percentages for transformers 1000 V or less are based on what?

• a.The secondary conductor ampacity
• b.The connected load kVA
• c.The rated primary (and where applicable secondary) current of the transformer✓
• d.The available fault current

Table 450.3(B) percentages (e.g., 125%, 167%, 250%, 300%) are applied to the transformer's rated primary or secondary current, not the load or fault current. This protects the transformer itself; separate rules protect the secondary conductors.2023 NEC §450.3

What is the rated primary current of a 25 kVA, single-phase transformer with a 240 V primary?

• a.60 A
• b.83 A
• c.96 A
• d.104 A✓

For a single-phase transformer, I = VA / V = 25,000 / 240 = 104 A. Using 208 V would give 120 A, 300 V gives 83 A, and 416 V gives 60 A; only the correct 240 V yields about 104 A.

A 45 kVA, three-phase transformer has a 208 V secondary. What is the rated secondary current?

• a.125 A✓
• b.108 A
• c.216 A
• d.150 A

For three-phase, I = VA / (1.732 x V) = 45,000 / (1.732 x 208) = 45,000 / 360 = about 125 A. Dividing by 208 alone (216 A) ignores the sqrt(3) factor, and the other values use wrong voltages.

Why must a motor circuit have both overload protection AND short-circuit/ground-fault protection?

• a.They are the same device required in two locations
• b.Overload devices protect against sustained overcurrents from motor running conditions, while short-circuit/ground-fault devices clear high-magnitude faults✓
• c.Overloads clear faults faster than breakers
• d.Short-circuit devices also sense motor running overload

Overload devices (sized ~115-125% of FLA) protect the motor and conductors from sustained overloads but are too slow for faults; branch-circuit short-circuit/ground-fault devices (sized much higher per Table 430.52) clear high fault currents. NEC 430 requires both because each addresses a different hazard.2023 NEC §430.31

A 30 HP, 460 V, three-phase motor has an FLC of 40 A. What is the minimum ampere rating of the motor disconnecting means (115% of FLC)?

• a.40 A
• b.44 A
• c.46 A✓
• d.50 A

NEC 430.110(A) requires the disconnect to be at least 115% of FLC: 40 x 1.15 = 46 A. 40 A ignores the factor, 44 A is 110%, and 50 A is 125% (used for conductors, not the minimum disconnect).2023 NEC §430.110

Under NEC 430.102(B), where must the disconnecting means for a motor generally be located?

• a.At the service equipment only
• b.At least 50 ft from the motor
• c.Anywhere in the building
• d.In sight from the motor location and the driven machinery✓

NEC 430.102(B) requires a disconnecting means in sight from the motor and the driven machinery (with limited exceptions where a lockable disconnect elsewhere is permitted). 'In sight' means visible and not more than 50 ft away. Service-only or remote-only placement does not satisfy the rule.2023 NEC §430.102

Per NEC Table 430.248, what is the full-load current of a 3 HP, single-phase, 115 V motor?

• a.34 A✓
• b.17 A
• c.24 A
• d.56 A

Table 430.248 lists 34 A for a 3 HP, 115 V single-phase motor. 17 A is the same HP at 230 V, 24 A is a 2 HP 115 V motor, and 56 A is a 5 HP 115 V motor.2023 NEC Table 430.248

For the 3 HP, 115 V single-phase motor (FLC 34 A), what minimum branch-circuit conductor ampacity does NEC 430.22 require?

• a.34 A
• b.42.5 A✓
• c.38.25 A
• d.46.75 A

NEC 430.22 requires 125% of FLC for a single continuous-duty motor: 34 x 1.25 = 42.5 A. 34 A omits the factor, 38.25 A uses 112.5%, and 46.75 A uses 137.5%.2023 NEC §430.22

Using NEC Table 430.250, what is the full-load current of a 50 HP, 460 V, three-phase motor?

• a.52 A
• b.77 A
• c.65 A✓
• d.96 A

Table 430.250 lists 65 A for a 50 HP, 460 V three-phase motor. 52 A is 40 HP, 77 A is 60 HP, and 96 A is 75 HP at 460 V.2023 NEC Table 430.250

For the 50 HP, 460 V motor (FLC 65 A), what minimum branch-circuit conductor ampacity is required by NEC 430.22?

• a.65 A
• b.71.5 A
• c.74.75 A
• d.81.25 A✓

430.22 requires 125% of FLC: 65 x 1.25 = 81.25 A. 65 A omits the factor, 71.5 A is 110%, and 74.75 A is 115%.2023 NEC §430.22

For the 50 HP, 460 V motor (FLC 65 A), what is the maximum inverse-time circuit breaker per the 250% column of Table 430.52?

• a.162.5 A✓
• b.113.75 A
• c.195 A
• d.520 A

Inverse-time breaker: 250% of FLC = 65 x 2.50 = 162.5 A (then next-standard-size rule may apply). 113.75 A is 175% (dual-element fuse), 195 A is 300% (nontime-delay fuse), and 520 A is 800% (instantaneous trip).2023 NEC §430.52

For a continuous-duty three-phase motor rated more than 1 HP without integral overload protection, how many overload units are generally required?

• a.One overload unit total
• b.One overload unit in each phase (three for a three-phase motor)✓
• c.Two units for any motor
• d.None if a breaker is used

NEC 430.37 and Table 430.37 require an overload device in each ungrounded conductor - three units for a three-phase motor - so a loss of one phase or unbalanced overload is detected. A single unit is insufficient, and a branch-circuit breaker does not provide running overload protection.2023 NEC §430.37

A continuous-duty motor has a nameplate FLA of 62 A and a service factor of 1.15. What is the maximum overload device rating at 125% under NEC 430.32(A)(1)?

• a.62 A
• b.71.3 A
• c.77.5 A✓
• d.86.8 A

125% of nameplate FLA for an SF >=1.15 motor: 62 x 1.25 = 77.5 A. 62 A omits the factor, 71.3 A is 115%, and 86.8 A is 140% (the higher trip ceiling of 430.32(C), used only when the 125% device won't allow starting).2023 NEC §430.32

If the 125% overload device will not allow a 62 A (SF 1.15) motor to start, NEC 430.32(C) permits increasing the overload trip setting to a maximum of what value?

• a.77.5 A (125%)
• b.80.6 A (130%)
• c.83.7 A (135%)
• d.86.8 A (140%)✓

NEC 430.32(C) allows the overload trip to be increased to a maximum of 140% of nameplate FLA (for SF >=1.15 motors) when the sized device won't let the motor start: 62 x 1.40 = 86.8 A. 130% and 135% are not the code ceiling, and 125% is the initial value.2023 NEC §430.32

Per NEC Table 430.248, what is the full-load current of a 2 HP, single-phase, 230 V motor?

• a.12 A✓
• b.24 A
• c.10 A
• d.17 A

Table 430.248 lists 12 A for a 2 HP, 230 V single-phase motor. 24 A is the same HP at 115 V, 10 A is a 1.5 HP 230 V motor, and 17 A is a 3 HP 230 V motor.2023 NEC Table 430.248

Using NEC Table 430.250, what is the full-load current of a 100 HP, 460 V, three-phase motor?

• a.156 A
• b.124 A✓
• c.96 A
• d.248 A

Table 430.250 lists 124 A for a 100 HP, 460 V three-phase motor. 156 A is 125 HP, 96 A is 75 HP, and 248 A is a 100 HP motor at 230 V.2023 NEC Table 430.250

For a 100 HP, 460 V motor (FLC 124 A), what minimum branch-circuit conductor ampacity does NEC 430.22 require?

• a.124 A
• b.136.4 A
• c.155 A✓
• d.174.6 A

430.22 requires 125% of FLC: 124 x 1.25 = 155 A. 124 A omits the factor, 136.4 A is 110%, and 174.6 A is about 141%.2023 NEC §430.22

For the 100 HP, 460 V motor (FLC 124 A), what is the maximum dual-element (time-delay) fuse per Table 430.52 (175%)?

• a.310 A
• b.372 A
• c.155 A
• d.217 A✓

Dual-element time-delay fuse: 175% of FLC = 124 x 1.75 = 217 A. 310 A is 250% (inverse-time breaker), 372 A is 300% (nontime-delay fuse), and 155 A is 125% (conductor factor).2023 NEC §430.52

In a typical motor branch circuit, which sequence correctly lists the components from the supply toward the motor?

• a.Branch-circuit short-circuit/ground-fault device, disconnecting means, controller, overload device, motor✓
• b.Motor, overload, controller, disconnect, fuse
• c.Overload, motor, controller, disconnect
• d.Controller, motor, fuse, disconnect

Article 430 arranges the motor circuit as: branch-circuit short-circuit/ground-fault protection, then the disconnecting means, then the controller, then the overload device, then the motor. The other sequences misplace the protective and control elements.2023 NEC §430.1

An HVAC nameplate lists MCA = 27.5 A and MOCP = 45 A. What is the minimum ampacity the branch-circuit conductors must have?

• a.45 A
• b.27.5 A✓
• c.22 A
• d.35 A

Conductors must have an ampacity at least equal to the MCA (27.5 A); the MOCP (45 A) is the maximum overcurrent device, not the conductor ampacity. Sizing conductors to 45 A would be oversized/incorrect, and 22 A is below the required MCA.2023 NEC §440.4

A rooftop A/C unit has one compressor at 30 A rated-load and a condenser fan at 1.5 A. What is the minimum circuit ampacity (MCA), using 125% of the largest motor plus other loads?

• a.37.5 A
• b.31.5 A
• c.39 A✓
• d.40.5 A

MCA = (30 x 1.25) + 1.5 = 37.5 + 1.5 = 39 A. 37.5 A forgets the fan, 31.5 A applies 125% to a wrong base, and 40.5 A applies 125% to both loads.2023 NEC §440.33

An HVAC nameplate specifies 'Maximum Fuse or HACR Breaker.' What does HACR indicate?

• a.The breaker must be a GFCI type
• b.The breaker must be rated for 100% continuous duty
• c.Only fuses may be used, not breakers
• d.The circuit breaker is rated/listed for heating, air-conditioning, and refrigeration group-motor applications✓

HACR-rated breakers are listed for heating, air-conditioning, and refrigeration equipment with group motor-compressor loads. The nameplate permits either a fuse or an HACR breaker up to the marked value; it does not mandate GFCI or fuses-only.2023 NEC §440.22

What is the rated secondary current of a 75 kVA, three-phase transformer with a 208 V secondary?

• a.208 A✓
• b.360 A
• c.180 A
• d.125 A

Three-phase current: I = 75,000 / (1.732 x 208) = 75,000 / 360 = about 208 A. Dividing by 208 V alone (360 A) omits sqrt(3), and the other values use wrong kVA or voltage.

For the 75 kVA transformer with a 208 A secondary, what is the maximum secondary overcurrent protective device using the 125% value of Table 450.3(B)?

• a.208 A
• b.260 A✓
• c.347 A
• d.416 A

Table 450.3(B) allows secondary protection at 125% of rated secondary current (currents >=9 A): 208 x 1.25 = 260 A. 208 A omits the factor, 347 A is about 167%, and 416 A is 200%.2023 NEC §450.3

NEC 450.9 requires that transformer ventilation openings be arranged so that they:

• a.Are always fitted with fans
• b.Face downward only
• c.Are not blocked by walls or obstructions, allowing required airflow to dissipate heat✓
• d.Are sealed to keep out dust

NEC 450.9 requires ventilation so transformers can dissipate full-load losses without exceeding temperature ratings; openings must not be blocked by walls or obstructions. Forced ventilation is not always required, and sealing openings would defeat cooling.2023 NEC §450.9

A feeder supplies three 460 V, three-phase motors: 25 HP (34 A), 15 HP (21 A), and 10 HP (14 A). Per NEC 430.24, what minimum feeder ampacity is required?

• a.69 A
• b.86.25 A
• c.84 A
• d.77.5 A✓

430.24 requires 125% of the largest FLC plus the sum of the rest: (34 x 1.25) + 21 + 14 = 42.5 + 35 = 77.5 A. 69 A omits the 125% factor, 86.25 A applies 125% to all, and 84 A doubles wrongly.2023 NEC §430.24

Per NEC 430.62, the maximum feeder overcurrent device for several motors equals the largest branch-circuit protective device rating plus the sum of the other motors' FLCs. If the largest motor's branch device is 90 A and the other motors' FLCs total 35 A, what is the maximum feeder device?

• a.125 A✓
• b.215 A
• c.90 A
• d.160 A

430.62(A): 90 A (largest branch device) + 35 A (sum of other FLCs) = 125 A maximum. 215 A wrongly adds all device ratings, 90 A ignores the other motors, and 160 A uses the wrong sum.2023 NEC §430.62

The equipment grounding conductor for a motor branch circuit is sized based on what, per NEC 250.122?

• a.The motor horsepower
• b.The rating of the branch-circuit short-circuit/ground-fault protective device✓
• c.The full-load current only
• d.The conductor insulation temperature

NEC 250.122 sizes the equipment grounding conductor from Table 250.122 using the rating of the overcurrent device (the branch-circuit short-circuit/ground-fault device) ahead of the equipment. Horsepower, FLC alone, and insulation rating do not directly set the EGC size.2023 NEC §250.122

Per NEC Table 430.250, what is the full-load current of a 7.5 HP, 230 V, three-phase motor?

• a.15.2 A
• b.28 A
• c.22 A✓
• d.11 A

Table 430.250 lists 22 A for a 7.5 HP, 230 V three-phase motor. 15.2 A is 5 HP, 28 A is 10 HP at 230 V, and 11 A is 7.5 HP at 460 V.2023 NEC Table 430.250

For the 7.5 HP, 230 V motor (FLC 22 A), what minimum branch-circuit conductor ampacity is required by NEC 430.22?

• a.22 A
• b.24.2 A
• c.25.3 A
• d.27.5 A✓

125% of FLC: 22 x 1.25 = 27.5 A. 22 A omits the factor, 24.2 A is 110%, and 25.3 A is 115%.2023 NEC §430.22

For the 7.5 HP, 230 V motor (FLC 22 A), what is the maximum nontime-delay fuse per Table 430.52 (300%)?

• a.66 A✓
• b.55 A
• c.38.5 A
• d.176 A

Nontime-delay fuse: 300% of FLC = 22 x 3.00 = 66 A. 55 A is 250% (inverse-time breaker), 38.5 A is 175% (dual-element fuse), and 176 A is 800% (instantaneous trip).2023 NEC §430.52

When the Table 430.52 percentage produces a value that does not correspond to a standard fuse or breaker size, NEC 430.52(C)(1) Exception No. 1 permits you to:

• a.Round down to the next lower standard size
• b.Use the next higher standard size of protective device✓
• c.Double the value
• d.Ignore the table and use conductor ampacity

430.52(C)(1) Exception No. 1 allows using the next higher standard size when the calculated maximum does not match a standard rating, so the motor can start. Rounding down could cause nuisance tripping; doubling or ignoring the table is not permitted.2023 NEC §430.52

Per NEC Table 430.248, what is the full-load current of a 1 HP, single-phase, 115 V motor?

• a.9.8 A
• b.13.8 A
• c.16 A✓
• d.20 A

Table 430.248 lists 16 A for a 1 HP, 115 V single-phase motor. 9.8 A is 1/2 HP, 13.8 A is 3/4 HP, and 20 A is 1.5 HP at 115 V.2023 NEC Table 430.248

A small single-phase motor has a nameplate FLA of 14 A, service factor 1.0, no marked temperature rise. What is the maximum overload device rating under NEC 430.32(A)(1)?

• a.14 A
• b.17.5 A
• c.15.4 A
• d.16.1 A✓

Without a 1.15+ SF or <=40C rise marking, overload is limited to 115% of nameplate: 14 x 1.15 = 16.1 A. 125% (17.5 A) applies only to qualifying motors, 15.4 A is 110%, and 14 A applies no factor.2023 NEC §430.32

NEC 430.75 requires that motor control circuits be arranged so that:

• a.The control circuit is disconnected from all sources of supply when the disconnecting means is open✓
• b.Control circuits are always 24 V
• c.Control conductors are the same size as power conductors
• d.Control circuits need no overcurrent protection

NEC 430.75 requires the disconnecting means to open the motor control circuit from all sources when placed in the off position (with limited exceptions), so a technician is not exposed to energized controls. Control voltage level, conductor size parity, and 'no protection' are not the rule.2023 NEC §430.75

A 15 kVA, single-phase transformer has a 480 V primary. What is the rated primary current?

• a.62.5 A
• b.31.25 A✓
• c.36 A
• d.72 A

Single-phase: I = 15,000 / 480 = 31.25 A. Using 240 V would give 62.5 A, and the other values use incorrect voltages or the sqrt(3) factor that does not apply to single-phase.

For the 15 kVA, 480 V single-phase transformer (primary current 31.25 A), what is the maximum primary-only overcurrent device using the 125% factor of Table 450.3(B)?

• a.31.25 A
• b.46.9 A
• c.39.1 A✓
• d.62.5 A

Primary current >=9 A limits primary-only protection to 125%: 31.25 x 1.25 = 39.1 A (next standard size up permitted where needed). 31.25 A omits the factor, 46.9 A is 150%, and 62.5 A is 200%.2023 NEC §450.3

Which of the following is NOT required to be marked on a motor nameplate by NEC 430.7?

• a.Rated full-load amperes
• b.Rated voltage and horsepower (or kW)
• c.Rated frequency and number of phases
• d.The branch-circuit conductor size to be installed✓

NEC 430.7 requires the manufacturer, voltage, HP/kW, FLA, frequency, phases, speed, and similar data on the nameplate, but not the field branch-circuit conductor size - that is the installer's design calculation. All other listed items are required nameplate markings.2023 NEC §430.7

For a permanently installed swimming pool, what conductor is required for the equipotential bonding grid?

• a.No. 10 AWG stranded copper
• b.No. 8 AWG solid copper✓
• c.No. 6 AWG solid aluminum
• d.No. 12 AWG insulated copper

Section 680.26(B) requires the equipotential bonding to be established with a minimum No. 8 AWG solid copper conductor. Aluminum is not permitted in contact with pool structures, and conductors smaller than 8 AWG or stranded are not accepted for the bonding grid.2023 NEC §680.26

A non-Type IC recessed luminaire must be spaced at least how far from combustible material, except at the points of support?

• a.1/2 inch✓
• b.1 inch
• c.3 inches
• d.6 inches

Section 410.116(A)(1) requires a minimum 1/2 inch clearance between a non-Type IC recessed luminaire and combustible material, except at the points where the fixture is supported. Larger clearances such as 3 inches apply to thermal insulation, not to the general combustible-material spacing.2023 NEC §410.116

Thermal insulation must be kept at least how far from a non-Type IC recessed luminaire enclosure?

• a.1/2 inch
• b.1 inch
• c.3 inches✓
• d.6 inches

Section 410.116(B) requires thermal insulation to be kept at least 3 inches from the enclosure of a non-Type IC recessed luminaire so heat is not trapped. Only a luminaire identified as Type IC may be in direct contact with insulation; the smaller clearances apply to combustible material spacing, not insulation.2023 NEC §410.116

An emergency system must make power available to the required loads within what maximum time after normal power is lost?

• a.10 seconds✓
• b.60 seconds
• c.2 minutes
• d.Immediately, with no delay permitted

Section 700.12 requires that current supply to emergency loads be available within 10 seconds of the failure of the normal supply. Sixty seconds is the limit for legally required standby systems under Article 701, and no time limit is given for optional standby (Article 702).2023 NEC §700.12

A legally required standby system must restore power to its loads within what maximum time after normal supply is lost?

• a.10 seconds
• b.30 seconds
• c.60 seconds✓
• d.120 seconds

Section 701.12 requires that a legally required standby system supply its loads within 60 seconds of a normal-supply failure. The 10-second figure applies to true emergency systems (Article 700), which serve life-safety loads that need faster restoration.2023 NEC §701.12

How is the maximum current of a PV source circuit determined for conductor and overcurrent sizing?

• a.By the rated operating current only
• b.1.0 times the short-circuit current
• c.0.8 times the short-circuit current
• d.1.25 times the short-circuit current (Isc)✓

Section 690.8(A) sets the maximum PV source-circuit current at 1.25 times the module short-circuit current (Isc) to account for irradiance above standard test conditions. Conductors and overcurrent devices are then sized per 690.8(B); using only the operating current or a factor of 1.0 would undersize the circuit.2023 NEC §690.8

Rapid shutdown requires that controlled conductors more than 1 foot outside the array boundary be limited to what within 30 seconds?

• a.80 volts within 10 seconds
• b.30 volts within 30 seconds✓
• c.50 volts within 1 minute
• d.0 volts instantly

Section 690.12 requires that conductors leaving the array boundary be reduced to no more than 30 volts within 30 seconds of rapid-shutdown initiation. This protects firefighters and responders; the 80-volt limit applies only inside the array boundary, not to the outside conductors.2023 NEC §690.12

The ampacity of conductors from a generator terminal to the first overcurrent device must be at least what percent of the generator nameplate current rating?

• a.100%
• b.110%
• c.115%✓
• d.125%

Section 445.13(A) requires the conductors from generator terminals to the first distribution device to have an ampacity of not less than 115 percent of the nameplate current rating. This margin covers the generator's ability to deliver current above its continuous rating; 100 or 110 percent would be insufficient.2023 NEC §445.13

In a clothes closet, a surface-mounted incandescent or LED luminaire with a completely enclosed light source must maintain what minimum clearance to the nearest storage space?

• a.12 inches✓
• b.6 inches
• c.18 inches
• d.3 inches

Section 410.16(C)(1) requires a minimum 12-inch clearance between a surface-mounted incandescent or completely enclosed LED luminaire and the nearest point of a storage space. Recessed fixtures are allowed a smaller 6-inch clearance because their heat is contained within the ceiling.2023 NEC §410.16

In a clothes closet, a recessed incandescent or LED luminaire with a completely enclosed light source must maintain what minimum clearance to the nearest storage space?

• a.12 inches
• b.18 inches
• c.24 inches
• d.6 inches✓

Section 410.16(C)(3) permits a 6-inch minimum clearance for recessed incandescent or completely enclosed LED luminaires because the recessed housing limits exposed heat. Surface-mounted units require the larger 12-inch clearance.2023 NEC §410.16

Under the 2023 NEC, what unit load is used to calculate the general lighting load for a dwelling unit?

• a.1 VA per square foot
• b.3 VA per square foot✓
• c.5 VA per square foot
• d.10 VA per square foot

Table 220.12 in the 2023 NEC assigns 3 VA per square foot for the general lighting and general-use receptacle load of a dwelling unit. This value is multiplied by the floor area (using outside dimensions) to determine the calculated general lighting load.2023 NEC §220.41

A luminaire installed in a wet location must be marked with what designation?

• a.Damp locations only
• b.Weather resistant
• c.Suitable for Wet Locations✓
• d.Outdoor use

Section 410.10(A) requires luminaires installed in wet locations to be marked 'Suitable for Wet Locations' and installed so water cannot enter or accumulate in wiring compartments or lampholders. A 'damp locations' marking is not sufficient for a wet location such as one exposed to rain or hose-down.2023 NEC §410.10

Cord-connected luminaires, hanging luminaires, and similar equipment shall not have parts located within what zone measured from the bathtub rim or shower threshold, unless marked for damp or wet locations?

• a.3 feet horizontally and 8 feet vertically✓
• b.5 feet horizontally and 8 feet vertically
• c.3 feet horizontally and 6 feet vertically
• d.6 feet horizontally and 10 feet vertically

Section 410.10(D) prohibits such luminaire parts within a zone 3 feet horizontally and 8 feet vertically from the top of the bathtub rim or shower stall threshold, unless the luminaire is listed for damp or wet locations. This keeps ordinary fixtures out of reach of a person in the tub or shower.2023 NEC §410.10

The top of a wet-niche underwater pool luminaire lens (other than a listed low-voltage unit) must be installed at least how far below the normal water level?

• a.6 inches
• b.12 inches
• c.24 inches
• d.18 inches✓

Section 680.23(A)(5) requires the top of a wet-niche luminaire lens to be at least 18 inches below the normal water level. Listed low-voltage luminaires with no exposed metal parts may be as little as 4 inches below the surface, but the general rule is 18 inches.2023 NEC §680.23

What is the maximum voltage permitted for a wet-niche underwater pool luminaire?

• a.120 volts
• b.150 volts✓
• c.250 volts
• d.60 volts

Section 680.23(A)(4) limits underwater luminaires to a maximum of 150 volts between conductors. Higher voltages such as 250 volts are not permitted for underwater pool lighting because of the shock hazard in and around water.2023 NEC §680.23

How must the wiring of an emergency system generally be arranged relative to all other wiring?

• a.Run in the same raceway as normal branch circuits
• b.Combined with legally required standby wiring
• c.Kept entirely independent of all other wiring✓
• d.Installed only in a metal raceway shared with feeders

Section 700.10(B) requires emergency-system wiring to be kept entirely independent of all other wiring and equipment, with only limited exceptions such as in transfer equipment or common junction boxes at fixtures. Sharing raceways with normal or legally required standby wiring is not permitted.2023 NEC §700.10

Transfer equipment used for an emergency system must be what?

• a.Automatic and listed for emergency use✓
• b.A manual knife switch
• c.Any general-use switch rated for the load
• d.A molded-case circuit breaker only

Section 700.5 requires transfer equipment for emergency systems to be automatic, identified for emergency use, and approved by the authority having jurisdiction. A manual knife switch or ordinary general-use switch cannot meet the automatic-transfer and listing requirements for life-safety loads.2023 NEC §700.5

For an optional standby system, what signage does the NEC require?

• a.No signage is required
• b.A sign only inside the generator enclosure
• c.A sign only if the system is over 600 volts
• d.A sign at the service-equipment location indicating the type and location of the on-site optional standby power source✓

Section 702.7 requires a sign at the service-equipment or grounding-electrode location indicating the type and location of each on-site optional standby power source. This warns anyone working on the service that a second source of supply exists; signage is not limited to high-voltage systems or the generator enclosure.2023 NEC §702.7

On a portable generator, GFCI protection for personnel is generally required on which receptacles?

• a.Not required on generators
• b.Required on 125 V, 15 A and 20 A receptacles✓
• c.Required only above 50 A
• d.Required only on 240 V outlets

Section 445.20 requires that 125-volt, 15- and 20-ampere receptacles on portable generators be provided with listed GFCI protection for personnel (or comply with the limited exception for older equipment). Protection is targeted at the common 125-volt convenience outlets used with cord sets, not only high-amperage circuits.2023 NEC §445.20

A generator disconnecting means must be capable of doing what?

• a.It is optional for standby units
• b.Only opening the neutral conductor
• c.Disconnecting the generator and all protective devices and control apparatus, and be lockable in the open position✓
• d.Serving as a plug and receptacle only

Section 445.18 requires a disconnecting means that shuts down the generator, disconnects it and all protective devices and control apparatus from the load, and can be locked in the open position. Opening only the neutral or relying on a cord-and-plug connection does not satisfy the full disconnect and lockout requirement.2023 NEC §445.18

How must emergency illumination be arranged with respect to the failure of a single lighting element?

• a.Failure of any individual lighting element shall not leave the area in total darkness✓
• b.A single bulb per room is acceptable
• c.Only exit signs are required
• d.Battery packs are prohibited

Section 700.16 requires emergency lighting to be designed and installed so that the failure of any individual lighting element, such as a single lamp burning out, cannot leave any space that requires emergency lighting in total darkness. Relying on a single bulb per room would violate this single-failure requirement.2023 NEC §700.16

Which loads are typically served by a legally required standby system?

• a.Personal comfort loads in a residence
• b.Life-safety egress lighting only
• c.Data-center revenue equipment chosen by the owner
• d.Ventilation, smoke removal, and communication systems required by code for safety✓

Legally required standby systems (Article 701) supply loads such as heating and ventilation, smoke removal, sewage disposal, and communication systems whose failure could create hazards or hamper firefighting and rescue. Pure life-safety egress loads fall under emergency systems (700), and owner-selected convenience loads fall under optional standby (702).2023 NEC §701.2

Transfer equipment for an optional standby system must do what regarding the normal and standby sources?

• a.Allow the generator to backfeed the utility freely
• b.Prevent inadvertent interconnection of the normal and standby sources✓
• c.Require no interlock between sources
• d.Always be an automatic type

Section 702.5 requires transfer equipment to prevent the inadvertent interconnection of the normal source and any optional standby source, unless the installation is designed for parallel operation per Article 705. Allowing free backfeed to the utility would endanger line workers; optional standby transfer equipment may be manual or automatic.2023 NEC §702.5

What does the NEC require regarding testing of emergency systems?

• a.No testing once commissioned
• b.Testing only every 10 years
• c.Periodic testing on a scheduled basis under simulated or maximum load✓
• d.Testing performed only by the utility

Section 700.3 requires emergency systems to be tested periodically on a schedule acceptable to the authority having jurisdiction to ensure they are maintained in proper operating condition, including a witnessed acceptance test at installation. Leaving a system untested after commissioning would violate this requirement.2023 NEC §700.3

What capacity must an emergency system power source have?

• a.Adequate capacity to carry all emergency loads simultaneously✓
• b.50% of the connected emergency load
• c.Only the largest single load
• d.No minimum capacity is specified

Section 700.4 requires the emergency source to have adequate capacity and rating to supply all loads that will operate simultaneously. Sizing for only a fraction of the load or the largest single load would leave emergency loads unsupplied during an outage.2023 NEC §700.4

A storage-battery emergency source must be capable of maintaining the total emergency load for what minimum time and voltage?

• a.30 minutes at 80% of nominal
• b.1 hour at 90% of nominal
• c.2 hours at 100% of nominal
• d.1 1/2 hours at not less than 87 1/2% of nominal voltage✓

Section 700.12 requires a storage battery serving as an emergency source to maintain the total load for a minimum of 1 1/2 hours without the voltage falling below 87 1/2 percent of nominal. Shorter durations or lower voltage thresholds do not meet the emergency-source requirement.2023 NEC §700.12

A PV system disconnecting means must be installed how?

• a.Located only on the roof
• b.Readily accessible and plainly marked as the PV system disconnect✓
• c.Optional for systems under 100 volts
• d.Concealed behind the inverter cover

Section 690.13 requires the PV system disconnecting means to be readily accessible and to be legibly marked to identify it as the photovoltaic system disconnect. A disconnect hidden on the roof or behind the inverter cover would not be readily accessible as required.2023 NEC §690.13

For a one- or two-family dwelling, what is the maximum permitted PV system DC voltage?

• a.1000 volts
• b.300 volts
• c.600 volts✓
• d.1500 volts

Section 690.7 limits the maximum PV system DC voltage on or in one- and two-family dwellings to 600 volts. The higher 1000-volt and 1500-volt levels are used on larger commercial and utility installations, not on dwellings.2023 NEC §690.7

Under the busbar interconnection rule, the sum of the main utility overcurrent device plus the inverter (power-production) overcurrent device generally may not exceed what percent of the busbar rating?

• a.120% of the busbar ampacity✓
• b.100% of the busbar ampacity
• c.150% of the busbar ampacity
• d.80% of the busbar ampacity

Section 705.12(B)(3) allows the sum of the ampere ratings of the main supply overcurrent device and the power-production (inverter) overcurrent device to be up to 120 percent of the busbar rating when the inverter breaker is at the opposite end from the main. Exceeding 120 percent would risk overloading the busbar.2023 NEC §705.12

The DC PV disconnect label must display what information?

• a.Only the manufacturer name
• b.Nothing is required
• c.AC frequency of the system
• d.Maximum PV system voltage and maximum circuit current of the DC circuit✓

Section 690.53 requires the DC photovoltaic system disconnect to be marked with the rated maximum voltage and the maximum circuit current for the DC circuits, among other values. This information helps responders and service personnel understand the DC hazard; manufacturer name or AC frequency alone would not satisfy the labeling requirement.2023 NEC §690.53

A power-limited fire alarm (PLFA) power source is limited to what maximum output?

• a.50 VA
• b.100 VA✓
• c.250 VA
• d.1000 VA

Section 760.121 limits a PLFA power source to the output of a listed Class 3 supply not exceeding 100 volt-amperes. Sources exceeding these limits are treated as non-power-limited fire alarm (NPLFA) circuits and must follow Chapter 3 wiring methods.2023 NEC §760.121

How must fire alarm circuit cables be installed and supported?

• a.Left unsupported above ceilings
• b.Run only in EMT
• c.Installed in a neat and workmanlike manner and supported so the cable will not be damaged by normal building use✓
• d.Bundled together with power conductors

Section 760.24 requires fire alarm cables to be installed in a neat and workmanlike manner, adequately supported by the building structure, and protected from physical damage. Leaving cable unsupported above a ceiling or bundling it with power conductors is not permitted; conduit is not the only allowed method.2023 NEC §760.24

What best characterizes a Class 2 circuit?

• a.Its power is limited by a listed Class 2 power source, providing protection from electric shock and fire ignition✓
• b.It operates above 600 volts
• c.It requires no overcurrent protection because it is high power
• d.It is identical to a Class 1 circuit

A Class 2 circuit's safety comes from limiting the power available from a listed Class 2 source, which restricts both shock and fire-ignition hazards. This power limitation is why Class 2 wiring is treated differently from Class 1 and from line-voltage power circuits.2023 NEC §725.121

How must Class 2 conductors generally be separated from electric light and power conductors?

• a.They may be freely mixed with 480 V conductors
• b.6 inches with no exceptions
• c.12 inches always
• d.At least 2 inches from power conductors unless a permitted separation method is used✓

Section 725.136 generally requires Class 2 conductors to be separated at least 2 inches from conductors of electric light, power, and Class 1 circuits, unless one of the permitted separation methods (such as a barrier or listed cable) is used. Freely mixing them in a raceway or enclosure with power conductors is not allowed.2023 NEC §725.136

When is a primary protector required on a communications circuit?

• a.Never required
• b.Where the circuit is exposed to lightning or to accidental contact with power conductors over 300 V to ground✓
• c.Required only for indoor circuits
• d.Required only for fiber-optic cable

Section 805.90 requires a listed primary protector where communications circuits are exposed to accidental contact with power conductors over 300 volts to ground or are subject to lightning exposure. Fiber-optic cables carry no metallic conductors, so they do not require this electrical protector.2023 NEC §805.90

What is the minimum size of the bonding/grounding conductor for a communications system?

• a.18 AWG copper
• b.16 AWG copper
• c.14 AWG copper✓
• d.10 AWG copper

Section 800.100 requires the communications bonding conductor or grounding-electrode conductor to be not smaller than 14 AWG copper (or equivalent). Smaller 16 or 18 AWG conductors would not meet the minimum, and 10 AWG is larger than required.2023 NEC §800.100

The equipotential bonding for perimeter surfaces around a permanently installed pool must extend how far from the inside walls of the pool?

• a.3 feet horizontally around the inside and outside pool walls✓
• b.5 feet
• c.10 feet
• d.1 foot

Section 680.26(B)(2) requires perimeter-surface bonding to extend for 3 feet horizontally beyond the inside walls of the pool and include walkways and surfaces within that zone. Larger distances such as 5 or 10 feet are not required by the equipotential-bonding rule.2023 NEC §680.26

A disconnecting means for pool utilization equipment such as a pump motor must be within sight and located at least how far from the inside walls of the pool?

• a.3 feet
• b.10 feet
• c.20 feet
• d.5 feet✓

Section 680.12 requires the disconnecting means for pool equipment to be readily accessible, within sight of the equipment, and located at least 5 feet horizontally from the inside walls of the pool unless separated by a permanent barrier. The 5-foot spacing keeps a person from reaching the disconnect while in the water.2023 NEC §680.12

General-purpose receptacles serving a dwelling-unit pool must be located at least how far from the inside walls of the pool?

• a.3 feet
• b.6 feet✓
• c.10 feet
• d.20 feet

Section 680.22(A) requires general-purpose receptacles to be located at least 6 feet from the inside walls of the pool. A required receptacle for pump-motor service may be between 6 and 20 feet away with GFCI protection; placing general receptacles closer than 6 feet is not permitted.2023 NEC §680.22

What GFCI requirement applies to the outlets supplying a packaged self-contained spa or hot tub?

• a.Not required
• b.Required only for indoor spas
• c.Required GFCI protection for the outlets supplying the spa or hot tub✓
• d.Required only above 240 volts

Section 680.44 generally requires the outlets that supply a self-contained spa or hot tub to be protected by a ground-fault circuit interrupter. This protection applies to both indoor and outdoor units and is not limited to higher-voltage circuits.2023 NEC §680.44

How must the water in a permanently installed pool be bonded to the equipotential bonding system?

• a.Through a conductive surface of at least 9 square inches in contact with the pool water✓
• b.Through 1 square inch of conductive surface
• c.Through 36 square inches of conductive surface
• d.The pool water does not need to be bonded

Section 680.26(C) requires the pool water to be bonded using an adequate conductive surface exposed to the pool water having a total area of at least 9 square inches, such as a listed metal fitting. This ensures the water is at the same potential as the surrounding bonded parts.2023 NEC §680.26

Low-voltage lighting systems covered by Article 411 are generally limited to what maximum voltage?

• a.120 volts
• b.60 volts
• c.12 volts only
• d.30 volts (or 15 volts where in direct contact with water)✓

Section 411.7 limits low-voltage lighting systems to a maximum of 30 volts (42.4 volts peak), reduced to 15 volts (21.2 volts peak) where the luminaires are installed in wet contact such as in a fountain. The 12-volt figure is a common operating voltage but is not the code maximum.2023 NEC §411.3

How must overcurrent devices in an emergency system be coordinated?

• a.Coordination is prohibited
• b.Selectively coordinated with all supply-side overcurrent protective devices✓
• c.Coordination is required only above 1000 volts
• d.Coordination is not addressed by the NEC

Section 700.32 requires emergency-system overcurrent protective devices to be selectively coordinated with all supply-side overcurrent devices. Selective coordination ensures that only the device nearest a fault opens, so a fault on one branch does not shut down the entire emergency system.2023 NEC §700.32

How does a Class 3 circuit differ from a Class 2 circuit?

• a.Class 3 is always lower power than Class 2
• b.Class 2 and Class 3 are identical
• c.Class 3 circuits are permitted at higher voltage and power than Class 2 and require additional protection against shock✓
• d.Class 3 is a line-voltage power circuit

Class 3 power sources are allowed to supply higher voltage and power levels than Class 2, so Article 725 imposes additional requirements to protect against electric shock. Class 3 is still a limited-energy circuit, not a general line-voltage power circuit.2023 NEC §725.121

When communications conductors share an enclosure with electric light or power conductors, what is required?

• a.They shall be separated by a barrier or maintained spacing from the power conductors✓
• b.They may share the same compartment freely
• c.They must be spliced together
• d.No separation is required at any voltage

Section 800.133 requires communications conductors to be separated from electric light, power, and Class 1 conductors, generally by a barrier or by maintaining a minimum spacing, when they occupy the same enclosure. Mixing them freely or splicing them to power conductors is not permitted.2023 NEC §800.133

What distinguishes a non-power-limited fire alarm (NPLFA) circuit from a power-limited (PLFA) circuit?

• a.Both are power-limited circuits
• b.NPLFA circuits are always 24 V battery-supplied
• c.PLFA circuits use Chapter 3 wiring methods only
• d.NPLFA circuits are not power-limited and must use Chapter 3 wiring methods, while PLFA circuits are power-limited✓

An NPLFA circuit is supplied by a source exceeding the power-limited restrictions and therefore must be installed using Chapter 3 wiring methods with 600-volt-rated conductors. PLFA circuits use a power-limited source (100 VA maximum) and may use the lighter power-limited cabling of Article 760 Part III.2023 NEC §760.41

Where must the initiation device for PV rapid shutdown be located?

• a.Inside the inverter only
• b.Readily accessible and located outside the building, or at an approved location for first responders✓
• c.It is not required
• d.Only on the roof next to the array

Section 690.12(C) requires the rapid-shutdown initiation device to be readily accessible and located outside the building or at another location approved for first responders. Placing it inside the inverter or hidden at the array would defeat its purpose of quick emergency access.2023 NEC §690.12

How must exposed non-current-carrying metal parts of PV module frames and equipment be treated?

• a.Frames need no bonding
• b.Bond only the inverter
• c.Exposed non-current-carrying metal parts of PV module frames and equipment shall be bonded and grounded✓
• d.Use only bare copper laid loosely on the roof

Section 690.43 requires exposed non-current-carrying metal parts of module frames, racking, and equipment to be bonded together and connected to an equipment grounding conductor, using listed devices or means. Bonding only the inverter or leaving frames unbonded would leave metal surfaces energized during a fault.2023 NEC §690.43

What marking must a generator carry?

• a.A nameplate giving the maker, rated frequency, power factor, kW or kVA, voltage, and rating such as continuous or standby✓
• b.No marking is required
• c.Only the serial number
• d.Only the fuel type

Section 445.11 requires each generator to have a nameplate giving the manufacturer, rated frequency, number of phases, subtransient and transient impedances, power factor, rating in kW or kVA, normal volts and amperes, and the rating (such as continuous, standby, or prime). A serial number or fuel-type marking alone would not satisfy this requirement.2023 NEC §445.11

An on-site generator serving as the emergency source must have an on-site fuel supply sufficient for what minimum operating time at full load?

• a.No on-site fuel is needed
• b.Fuel for 30 minutes
• c.Fuel for 1 hour
• d.On-site fuel for not less than 2 hours of full-demand operation✓

Section 700.12 requires a generator set used as an emergency source to have an on-site fuel supply sufficient for not less than 2 hours of full-demand operation of the system. A shorter supply, or relying only on an outside fuel source, would not meet the emergency requirement.2023 NEC §700.12

Which recessed luminaire may be installed in direct contact with thermal insulation?

• a.Any recessed can may touch insulation
• b.A luminaire that is identified and marked as Type IC✓
• c.No recessed luminaire may ever be near insulation
• d.Only fluorescent recessed luminaires

Section 410.116 permits only recessed luminaires identified and marked Type IC (Insulation Contact) to be installed in direct contact with thermal insulation. Non-IC luminaires must keep insulation at least 3 inches away, regardless of the lamp type used.2023 NEC §410.116

When may a luminaire be used as a raceway for circuit conductors?

• a.Any luminaire may be used as a raceway
• b.It is never permitted
• c.Only luminaires listed and marked for use as a raceway may carry pass-through conductors✓
• d.Only in commercial buildings

Section 410.64 permits luminaires to be used as a raceway for circuit conductors only where they are listed and marked for use as a raceway, or where they are designed for end-to-end connection to form a continuous raceway, or where conductors pass through as allowed. Using an ordinary luminaire not so listed as a raceway is prohibited.2023 NEC §410.64

Where is track lighting not permitted to be installed?

• a.In wet or damp locations, within 5 feet of a bathtub rim, or where concealed✓
• b.Anywhere it may be freely installed
• c.Only outdoors
• d.Only within 3 feet of a shower stall

Section 410.151(C) prohibits track lighting in wet or damp locations, within 5 feet horizontally of a bathtub rim, where subject to physical damage, where concealed, or where extended through walls or partitions, among other locations. Track lighting is not a general-purpose method that may be freely installed anywhere.2023 NEC §410.151

How must emergency unit equipment (self-contained battery luminaires) be supplied?

• a.Fed from any random branch circuit
• b.Kept portable and unplugged when not in use
• c.Fed only from the standby generator
• d.Permanently fixed and, for unit equipment, supplied from the same branch circuit as the normal area lighting, connected ahead of any local switch✓

Section 700.12 requires emergency unit equipment to be permanently fixed in place and supplied from the branch circuit serving the normal lighting in the same area, connected ahead of any local switches. This ensures the battery unit sees a loss of normal power the moment lighting in that space is lost.2023 NEC §700.12

What GFCI requirement applies to an underwater pool luminaire operating above the low-voltage contact limit?

• a.GFCI is never required for underwater luminaires
• b.Underwater luminaires operating over the low-voltage contact limit (over 15 volts) must have GFCI protection✓
• c.GFCI is required only for 120-volt units
• d.GFCI is required only for spas, not pools

Section 680.23(A)(3) requires ground-fault circuit-interrupter protection for underwater luminaires supplied at more than the low-voltage contact limit (over 15 volts). This protects swimmers from shock; the requirement is not limited to 120-volt units and is not exclusive to spas.2023 NEC §680.23