What should personnel do before working on a capacitor?

• A. Turn off power at the main breaker
• B. Replace the capacitor without discharge
• C. Ignore the capacitor
• D. Follow procedures for discharging the capacitor

Answer: (D)

Capacitors can hold a dangerous amount of energy even after power is removed, so the careful approach is to discharge the capacitor using the approved procedure before any work. This involves isolating the capacitor from the circuit, using the proper discharge method or tool, and then verifying with a reliable test that the voltage is zero. Only after the capacitor has been proven safe should you proceed.

Turning off the main breaker might stop power flow, but it does not guarantee the stored energy is removed, so it doesn’t fully address the hazard. Replacing a capacitor without discharging it is dangerous, and ignoring the capacitor creates a serious risk. Following the established discharging procedures directly targets and eliminates the energy hazard.