CSLB General Building (B) — All Questions
← Back to practice15 questions
For equipment operating at 0-150 V to ground under Condition 1, what is the minimum depth of working space in front of the equipment?
- a.2 ft
- b.2.5 ft
- c.4 ft
- d.3 ft✓
Condition 1 (exposed live parts on one side, no grounded parts opposite) requires a minimum working clearance of 3 ft for 0-150 V.2023 NEC 110.26(A)(1)
What is the minimum required width of working space in front of electrical equipment?
- a.30 in or the width of the equipment, whichever is greater✓
- b.24 in
- c.36 in always
- d.18 in
The working space width must be at least 30 in or the width of the equipment, whichever is greater, and must permit a 90-degree door opening.2023 NEC 110.26(A)(2)
What is the minimum headroom (height) of working space about electrical equipment such as panelboards?
- a.6 ft
- b.6.5 ft✓
- c.7 ft
- d.8 ft
The minimum headroom of working space is 6.5 ft (or the height of the equipment, whichever is greater).2023 NEC 110.26(A)(3)
The dedicated equipment space above a panelboard extends how far above the equipment (or to a structural ceiling if lower)?
- a.3 ft
- b.4.5 ft
- c.6 ft✓
- d.7 ft
The dedicated electrical space extends from the equipment to 6 ft above it, or to a structural ceiling if lower, and must be kept clear of foreign systems.2023 NEC 110.26(E)(1)
Equipment rated at what current or more requires two entrances to and egress from the working space when the space is large or contains overcurrent devices?
- a.800 A
- b.600 A
- c.1000 A
- d.1200 A✓
For equipment rated 1,200 A or more and over 6 ft wide, two entrances/egress paths to the working space are required.2023 NEC 110.26(C)(2)
For a circuit rated 100 A or less, conductor ampacity is generally based on which temperature column unless the equipment is listed otherwise?
- a.60 C✓
- b.75 C
- c.90 C
- d.105 C
Terminations on equipment rated 100 A or less are based on the 60 C column unless the equipment and conductors are listed for a higher temperature.2023 NEC 110.14(C)(1)
For circuits rated over 100 A, conductor ampacity for terminations is generally based on which temperature column?
- a.60 C
- b.75 C✓
- c.90 C
- d.Nameplate only
Terminations on equipment over 100 A are based on the 75 C column unless listed and marked for a higher rating.2023 NEC 110.14(C)(1)
Which standard governs electrical safety-related work practices, including arc-flash and shock protection?
- a.NEC (NFPA 70)
- b.NFPA 72
- c.NFPA 70E✓
- d.OSHA 1910 only
NFPA 70E, Standard for Electrical Safety in the Workplace, covers safe work practices, arc-flash boundaries, and PPE selection.
Under safe electrical work practices, what is the preferred condition before working on or near exposed conductors?
- a.Wearing rubber gloves
- b.Energized with a permit
- c.Under observation
- d.An electrically safe (de-energized and verified) work condition✓
The safest and preferred approach is to place equipment in an electrically safe work condition: de-energize, lock out, and verify absence of voltage before work.
What is the primary purpose of a lockout/tagout (LOTO) procedure under Cal/OSHA?
- a.To isolate and control hazardous energy during servicing✓
- b.To label panel directories
- c.To test GFCI devices
- d.To install ground rods
LOTO isolates and controls hazardous energy sources so equipment cannot be re-energized while workers are servicing it.
During electrical construction, a rough-in (rough) inspection is generally performed:
- a.After energizing the system
- b.Before wiring is concealed or covered✓
- c.Only at final occupancy
- d.After the final inspection
The rough inspection occurs after wiring is installed but before walls or wiring are covered, so the inspector can verify concealed work.
Who is responsible for interpreting and enforcing the requirements of the NEC?
- a.The equipment manufacturer
- b.The NFPA
- c.The authority having jurisdiction (AHJ)✓
- d.The serving utility
The authority having jurisdiction enforces the Code, makes interpretations, and grants any special permission where allowed.2023 NEC 90.4
The NEC generally does not cover which of the following installations?
- a.Dwelling branch circuits
- b.Commercial feeders
- c.Industrial services
- d.Utility-owned generation and distribution under exclusive utility control✓
The Code does not apply to installations under the exclusive control of an electric utility for generation, transmission, or distribution of power.2023 NEC 90.2(B)
Service equipment (other than dwellings) must be field marked with what value related to fault protection?
- a.Maximum available fault current✓
- b.The panel interrupting rating only
- c.Installation date only
- d.Phase rotation
Service equipment must be legibly field marked with the maximum available fault current and the date of the calculation.2023 NEC 110.24(A)
Equipment likely to be examined or serviced while energized must carry what type of field-applied marking?
- a.Voltage rating only
- b.An arc-flash hazard warning label✓
- c.Phase-sequence label
- d.Equipment grounding conductor size
An arc-flash warning label must be applied to warn qualified persons of the potential arc-flash hazard before energized examination or servicing.2023 NEC 110.16