CSLB Trade — Electrical (C-10) — All Questions

To protect other workers from an area where justified energized work is being performed, the qualified person should:

• a.Simply work faster to reduce exposure time
• b.Use barricades, warning signs, and an attendant if needed to keep unqualified persons out of the boundaries✓
• c.Do nothing because only they are at risk
• d.Turn off the room lights to signal danger

Energized work areas must be protected with barricades, signs, and an attendant when needed so unqualified persons stay outside the approach boundaries. Doing nothing exposes others, turning off lights creates a new hazard, and working fast does not control access to the hazard zone.

Class 00 and Class 0 rubber insulating gloves are rated for maximum AC use voltages of approximately:

• a.250 volts and 500 volts
• b.5,000 volts and 10,000 volts
• c.500 volts and 1,000 volts respectively✓
• d.50 volts and 100 volts

Class 00 gloves are rated to about 500V and Class 0 gloves to about 1,000V AC maximum use voltage. The 5,000/10,000V figures apply to higher classes, and 250/500V or 50/100V understate the ratings of these two glove classes.

When an arc-flash risk assessment requires it, in addition to arc-rated clothing a worker must protect the face and head with:

• a.An arc-rated face shield with balaclava, or an arc-rated flash-suit hood✓
• b.Nothing extra beyond the shirt
• c.A simple disposable dust mask
• d.A pair of tinted sunglasses

Face and head protection for arc flash means an arc-rated face shield with a balaclava (sock hood) or a full arc-rated flash-suit hood, selected to the incident energy. Sunglasses, a dust mask, or no additional protection do not shield the face from the intense heat and light of an arc.NFPA 70E

Standard electrical arc-flash PPE also includes head and hearing protection because:

• a.An arc blast produces intense heat, pressure, and sound, so a non-conductive (Class E) hard hat and hearing protection are required✓
• b.Hard hats are always optional for electricians
• c.Only the gloves matter during an arc event
• d.Electrical arcs are silent and harmless to the ears

An arc blast releases extreme heat, a pressure wave, and very loud sound, so a Class E (electrical) hard hat and hearing protection are part of the PPE. Arcs are far from silent, hard hats are not optional in this work, and gloves alone do not address the head, hearing, and blast hazards.

For electrical work, a hard hat should be:

• a.Class G only, tested to 1,000 volts
• b.Class C (conductive/vented) for better airflow
• c.Any bump cap will do
• d.Class E, tested to protect against electrical contact up to 20,000 volts✓

Class E (electrical) hard hats are dielectrically tested to protect against contact up to about 20,000 volts, making them the correct choice for electrical work. Class C is conductive and unsafe near electricity, a bump cap offers little impact protection, and Class G (about 2,200V) provides far less electrical protection than Class E.

Immediately after you open a disconnect switch, all the conductors on the load side should be treated as:

• a.Safe to handle right away
• b.Safe after waiting about five seconds
• c.Energized and dangerous until you have tested and verified the absence of voltage✓
• d.Safe as soon as the indicator light goes off

Conductors must be treated as energized until a rated tester confirms the absence of voltage; a disconnect could be mislabeled, back-fed, or have stored energy. Assuming safety from an open switch, an indicator light, or a short wait has caused many electrocutions.Cal/OSHA Title 8 §2320.1

On de-energized conductors or equipment where accidental re-energization or induced voltage is possible, workers protect themselves by applying:

• a.Temporary protective grounds (a grounding cluster) to keep the conductors at or near zero potential✓
• b.A warning sign at the panel and nothing more
• c.Nothing extra, since the switch is open
• d.Only rubber insulating blankets over the parts

Temporary protective grounds bond de-energized conductors together and to ground, so any accidental re-energization or induced voltage is shunted safely instead of flowing through a worker. An open switch, blankets, or a sign alone do not protect against an unexpected re-energization the way applied grounds do.

In a dwelling, 125-volt 15- and 20-ampere receptacles must be GFCI-protected in which of the following groups of locations?

• a.The attic
• b.The living room
• c.Bedrooms only
• d.Bathrooms, kitchens, garages, outdoors, crawl spaces, unfinished basements, laundry areas, and within 6 feet of a sink✓

The Code requires GFCI protection for dwelling receptacles in wet or damp and higher-risk areas—bathrooms, kitchens, garages, outdoors, crawl spaces, unfinished basements, laundry areas, and near sinks. Bedrooms, the living room, or the attic are not the code-listed GFCI locations by themselves.2023 NEC §210.8

What is the fundamental difference between AFCI and GFCI protection?

• a.AFCI detects the 5 mA shock current to protect people
• b.GFCI is designed to prevent arcing fires in walls
• c.GFCI protects people from shock by detecting ground-fault (leakage) current, while AFCI protects against fires by detecting dangerous arcing faults✓
• d.They are identical devices with different names

A GFCI detects small ground-fault/leakage current to protect people from shock, whereas an AFCI senses the signature of dangerous arcing and opens to prevent fires. They are not the same device, AFCI is not a 5 mA shock protector, and GFCI is not primarily a fire-prevention arc detector.

Flexible cords and extension cords used on a construction site must be:

• a.Of the hard-service or extra-hard-service type, include an equipment grounding conductor, and be inspected and free of damage✓
• b.Run through doorways where they can be pinched shut
• c.Repaired with electrical tape over any cuts
• d.Ordinary 16 AWG lamp cord for lighter tools

Jobsite cords must be hard- or extra-hard-service rated, contain a grounding conductor, and be inspected and undamaged. Taping over cuts, pinching cords in doorways, or using light lamp cord all create shock, ground-fault, and fire hazards and are not acceptable.

As an alternative to GFCI protection on certain construction-site receptacles, an employer may instead implement:

• a.Doubling the fuse or breaker size on the circuit
• b.No protection at all, relying on worker care
• c.A lockout/tagout program in place of any grounding checks
• d.An assured equipment grounding conductor program with documented, scheduled inspections and continuity tests of cords and equipment✓

OSHA allows an assured equipment grounding conductor program—documented, scheduled continuity and terminal tests on cords and equipment—as an alternative to GFCI on some receptacles. Providing no protection, oversizing overcurrent devices, or substituting a lockout program does not satisfy the ground-fault protection requirement.

Which set of actions best establishes an 'electrically safe work condition' before hands-on work begins?

• a.Reducing the connected load to lower the current
• b.Putting on rubber gloves and working the circuit while it is still energized
• c.Posting a warning sign near the equipment
• d.De-energize the source, lock and tag out, test for the absence of voltage, and apply temporary grounds where required✓

An electrically safe work condition is established by de-energizing, locking/tagging out, verifying zero voltage with a rated tester, and applying grounds where required. Gloved live work, a sign, or reducing load do not remove the energy source and therefore do not create a safe work condition.Cal/OSHA Title 8 §3314