WALMART MAINTENANCE Electrical Systems — Questions and Answers
Question 1: What is the FIRST step before performing any electrical maintenance work?
- Put on rubber gloves
- Lock out and tag out (LOTO) the energy source (Correct answer)
- Test the circuit with your hand
- Call the store manager
Correct answer: Lock out and tag out (LOTO) the energy source
Lockout/Tagout ensures that electrical systems are de-energized and cannot be accidentally re-energized during maintenance, preventing electrical shock or electrocution.
Question 2: What does a GFCI outlet protect against?
- Power surges
- Ground faults that could cause electrical shock (Correct answer)
- Lightning strikes
- Overloaded circuits
Correct answer: Ground faults that could cause electrical shock
A Ground Fault Circuit Interrupter detects current leakage to ground and rapidly shuts off power, protecting against electrical shock, especially in wet locations.
Question 3: What is the standard voltage for commercial lighting circuits in a US retail store?
- 120 volts
- 208/277 volts (Correct answer)
- 480 volts
- 12 volts
Correct answer: 208/277 volts
Most commercial lighting in US retail stores operates on 208V or 277V single-phase circuits, which is more efficient than 120V for lighting loads.
Question 4: What color wire indicates a ground conductor in US electrical systems?
- Black
- White
- Green or bare copper (Correct answer)
- Red
Correct answer: Green or bare copper
In US electrical wiring, green insulation or bare copper wire indicates the equipment grounding conductor, which provides a safe path for fault currents.
Question 5: A circuit breaker keeps tripping repeatedly. What should you investigate?
- Replace the breaker with a larger one
- Investigate the circuit for overloads, short circuits, or ground faults (Correct answer)
- Tape the breaker in the ON position
- Ignore it if the lights work when reset
Correct answer: Investigate the circuit for overloads, short circuits, or ground faults
Repeated tripping indicates a problem on the circuit. Investigating for overloads, shorts, or ground faults identifies the root cause rather than masking a potentially dangerous condition.
Question 6: What is the purpose of a ballast in a fluorescent light fixture?
- To hold the bulb in place
- To regulate the current flowing through the fluorescent lamp (Correct answer)
- To filter the light color
- To protect against water damage
Correct answer: To regulate the current flowing through the fluorescent lamp
A ballast regulates the electrical current to the fluorescent lamp, providing the initial high voltage to start the lamp and then limiting current during operation.
WALMART MAINTENANCE Electrical Systems
What is the FIRST step before performing any electrical maintenance work?