CSLB General Building (B) — All Questions

A location where ignitable concentrations of flammable gases or vapors exist under normal operating conditions is classified as:

• a.Class II, Division 1
• b.Class III
• c.Class I, Division 2
• d.Class I, Division 1✓

Class I covers flammable gases/vapors; Division 1 means ignitable concentrations can exist under normal operation, so it is Class I, Division 1.2023 NEC 500.5(B)(1)

A location made hazardous by combustible dust is classified as which class?

• a.Class II✓
• b.Class I
• c.Class III
• d.Class IV

Class II locations are those hazardous because of the presence of combustible dust.2023 NEC 500.5(C)

In a Class I, Division 1 location, a sealing fitting must be installed within what distance of an enclosure containing arcing devices?

• a.24 in
• b.18 in✓
• c.12 in
• d.36 in

Seals are required within 18 in of enclosures that contain devices which may produce arcs, sparks, or high temperatures.2023 NEC 501.15(A)

What is the minimum number of receptacles required at a general care (Category 2) patient bed location?

• a.4
• b.6
• c.8✓
• d.14

General care patient bed locations require a minimum of 8 receptacles, served from the normal and/or essential systems.2023 NEC 517.18(B)

What is the minimum number of receptacles required at a critical care (Category 1) patient bed location?

• a.8
• b.10
• c.12
• d.14✓

Critical care patient bed locations require a minimum of 14 receptacles.2023 NEC 517.19(B)

The equipotential bonding grid around a permanently installed pool must use a solid copper conductor no smaller than:

• a.#8 AWG✓
• b.#6 AWG
• c.#10 AWG
• d.#4 AWG

Pool equipotential bonding must use an insulated, covered, or bare solid copper conductor not smaller than #8 AWG.2023 NEC 680.26(B)

A required convenience receptacle for a dwelling pool must be located not less than what distance from the inside pool wall?

• a.10 ft
• b.6 ft✓
• c.5 ft
• d.8 ft

At least one receptacle is required between 6 ft and 20 ft from the inside wall; the minimum setback is 6 ft.2023 NEC 680.22(A)

A wet-niche underwater luminaire operating without GFCI protection is limited to a maximum of:

• a.120 V
• b.24 V
• c.15 V✓
• d.30 V

Underwater luminaires must be GFCI protected unless they operate at not more than the low-voltage contact limit of 15 V.2023 NEC 680.23(A)

A motor disconnecting means must have an ampere rating of at least what percent of the motor full-load current?

• a.100%
• b.110%
• c.125%
• d.115%✓

The disconnecting means for a motor must be rated at least 115% of the motor full-load current.2023 NEC 430.110(A)

A single hermetic refrigerant motor-compressor has a rated-load current of 24 A. What minimum branch-circuit conductor ampacity is required?

• a.30 A✓
• b.24 A
• c.36 A
• d.28 A

Conductors to a single motor-compressor must be at least 125% of the rated-load or branch-circuit selection current: 24 x 1.25 = 30 A.2023 NEC 440.32

A hermetic compressor has a rated-load current of 24 A. What is the maximum branch-circuit short-circuit and ground-fault device at 175% (next standard size)?

• a.40 A
• b.45 A✓
• c.50 A
• d.60 A

175% of 24 A = 42 A; the next standard overcurrent size is 45 A, which is the maximum permitted for short-circuit/ground-fault protection.2023 NEC 440.22(A)

Which nameplate value on an air-conditioning unit is used to size the branch-circuit conductors?

• a.Maximum overcurrent protection
• b.Nameplate horsepower
• c.Minimum circuit ampacity✓
• d.Rated-load amps only

Conductors are sized to the marked minimum circuit ampacity (MCA); the maximum overcurrent protective device (MOCP) sizes the breaker or fuse.2023 NEC 440.4

A Class 2 power-limited circuit at 30 V or less is limited to a maximum power of:

• a.1,000 VA
• b.250 VA
• c.500 VA
• d.100 VA✓

Class 2 circuits are inherently limited low-energy circuits; a typical alternating-current source limit is 100 VA at up to 30 V for reliable low-energy protection.2023 NEC Chapter 9 Table 11(B)

Cables listed for power-limited fire alarm use are marked with which type designation?

• a.FPL✓
• b.CL2
• c.CMR
• d.TC

Power-limited fire alarm cables carry the FPL family markings (FPL, FPLR riser, FPLP plenum).2023 NEC 760.179

Two 10-HP, 460-V motors (14 A each) are supplied by one feeder. What minimum feeder conductor ampacity is required?

• a.28 A
• b.31.5 A✓
• c.35 A
• d.25 A

125% of the largest motor plus the other: (14 x 1.25) + 14 = 17.5 + 14 = 31.5 A.2023 NEC 430.24

A motor without a marked service factor (or with SF under 1.15) has a full-load current of 28 A. What is the maximum overload protection at 115%?

• a.35 A
• b.28 A
• c.32.2 A✓
• d.30 A

For motors with a service factor less than 1.15, overload protection is limited to 115% of nameplate FLA: 28 x 1.15 = 32.2 A.2023 NEC 430.32(A)

Which wiring method is acceptable in a Class I, Division 2 location?

• a.Type NM
• b.Type AC
• c.Nonmetallic Romex
• d.Type MC with listed fittings✓

Class I, Division 2 permits methods such as threaded rigid metal conduit and Type MC cable with listed fittings; ordinary NM/AC cable is not permitted.2023 NEC 501.10(B)

A required branch circuit that supplies a sign or outline lighting system must be rated at least:

• a.20 A✓
• b.15 A
• c.30 A
• d.40 A

Each commercial building must have at least one dedicated 20-A branch circuit for a sign or outline lighting outlet.2023 NEC 600.5(B)

Low-voltage lighting systems covered by Article 411 are limited to a maximum circuit voltage of:

• a.24 V
• b.30 V✓
• c.15 V
• d.12 V

Article 411 low-voltage lighting systems operate at not more than 30 V (or 60 V DC for wet contact limits), commonly through a listed power supply.2023 NEC 411.5

Electrical equipment supplying a decorative fountain must have what protection?

• a.AFCI
• b.Surge protection
• c.GFCI✓
• d.Isolation transformer only

All electrical equipment associated with fountains, including luminaires and pumps, must be protected by a ground-fault circuit interrupter.2023 NEC 680.51(A)

The equipotential plane bonding conductor in an agricultural building must be:

• a.#8 Cu only if insulated
• b.#6 Cu maximum
• c.Insulated conductor only
• d.Copper conductor not smaller than #8✓

Bonding of the equipotential plane in agricultural buildings uses a copper conductor not smaller than #8 AWG, solid or the equivalent.2023 NEC 547.10

A motor feeder supplies motors whose largest branch device is 90 A, plus other motors with 50 A total full-load current. What is the maximum feeder short-circuit/ground-fault device (not to exceed the sum, next standard down)?

• a.125 A✓
• b.150 A
• c.175 A
• d.110 A

The feeder device may not exceed the largest branch-circuit device (90 A) plus the other FLCs (50 A) = 140 A; the largest standard rating not exceeding 140 A is 125 A.2023 NEC 430.62