When testing electric pumps and their controllers, what shall the inspector do first?

When testing electric pumps and their controllers, what shall the inspector do first?

• A. Apply lockout/tag out procedures.
• B. Determine all possible sources of electrical supply to the equipment.
• C. Open controller cabinet.
• D. Start pump and run for 30 minutes

Answer: (B)

Determining all possible electrical sources to the equipment before doing any work ensures complete energy isolation. Electric pumps and their controllers can have multiple feeds or backfeeds—main power, standby or backup power, UPS, batteries, and interlocks in the control circuits. If you skip identifying every source, you risk leaving something energized or allowing hidden backfeeds when you lock out, which is dangerous. Once you know all sources, you can apply lockout/tagout properly to prevent re-energization and verify that the system is de-energized. Only after confirming zero energy should you open the controller cabinet or attempt any testing, and never start the pump during testing.

Determining all possible electrical sources to the equipment before doing any work ensures complete energy isolation. Electric pumps and their controllers can have multiple feeds or backfeeds—main power, standby or backup power, UPS, batteries, and interlocks in the control circuits. If you skip identifying every source, you risk leaving something energized or allowing hidden backfeeds when you lock out, which is dangerous. Once you know all sources, you can apply lockout/tagout properly to prevent re-energization and verify that the system is de-energized. Only after confirming zero energy should you open the controller cabinet or attempt any testing, and never start the pump during testing.