CSLB C-46 Solar ContractorSafetyMedium
A solar installer is using a portable electric circular saw on a job site. Which of the following electrical safety features is REQUIRED by OSHA for this tool to protect against electrical shock?
- AA circuit breaker with an arc-fault detection interruptor (AFCI).
- BDouble insulation or an assured equipment grounding conductor program.
- CA dedicated transformer to step down the voltage.
- DA lockout/tagout (LOTO) device on the saw's power plug.
Show answer & explanationAnswer & explanation
Correct answer: B. Double insulation or an assured equipment grounding conductor program.
OSHA requires that portable electric tools either be double insulated or be protected by a ground-fault circuit interrupter (GFCI) or an assured equipment grounding conductor program (AEGCP) to prevent electrical shock.
Why the other options are wrong
- A. AFCI protection is primarily for fire prevention from arc faults, not direct protection against ground faults or shock from damaged insulation, which is the role of GFCI or grounding.
- C. Stepping down voltage with a transformer is not a general requirement for portable tools; the primary protection is grounding/double insulation or GFCI.
- D. LOTO is for de-energizing and securing equipment during maintenance, not for in-use shock protection of portable tools.
Portable Electric Tool Protection
OSHA requires portable electric tools to be either double-insulated or protected by a ground-fault circuit interrupter (GFCI) or an assured equipment grounding conductor program (AEGCP) to prevent electrical shock hazards.
- Double insulation provides a second layer of protective insulation.
- GFCI detects ground faults and quickly de-energizes the circuit.
- AEGCP involves regular testing of grounding paths.
Memory trick: Double up or ground down, keep shock hazards out of town!