CSLB C-36 Plumbing ContractorSafetyMedium
A plumber is using a reciprocating saw to cut through old cast iron pipes during a renovation project. To minimize the risk of electrical shock, what is the most appropriate electrical safety measure for the tool?
- AOperate the saw only when standing on a rubber mat.
- BUse a cordless reciprocating saw instead of a corded one.
- CEnsure the saw has a three-prong plug and is connected to a properly grounded outlet.
- DWear insulated gloves while operating the saw.
Show answer & explanationAnswer & explanation
Correct answer: C. Ensure the saw has a three-prong plug and is connected to a properly grounded outlet.
For corded power tools, proper grounding through a three-prong plug and a grounded outlet is the primary and most effective electrical safety measure to protect against shock if an internal fault occurs. This is often supplemented by a GFCI.
Why the other options are wrong
- A. Standing on a rubber mat provides some insulation but does not address faults within the tool itself and is not a substitute for proper grounding.
- B. While cordless tools eliminate the cord-related electrical shock risk, they introduce other considerations (battery safety, weight) and aren't always practical or available; proper grounding is the core safety for corded tools.
- D. Insulated gloves offer some protection but are not the primary line of defense for tool faults and may not be rated for high voltages.
Power Tool Grounding
The electrical safety feature that provides a low-resistance path for fault current to flow to the earth, preventing electrical shock to the user.
- Requires a three-prong plug and grounded outlet.
- Protects against internal electrical faults.
- Often supplemented by GFCI protection.
Memory trick: Ground your gear, banish the fear.