What is the first step to be taken before repairing a pump's electric motor?

Locking out and tagging the switch is crucial before attempting any repairs on a pump's electric motor. This safety procedure ensures that the equipment cannot be inadvertently powered on while someone is working on it. Lockout/tagout (LOTO) practices are designed to protect workers from the unexpected release of hazardous energy. By securing the switch, you effectively eliminate the risk of electrical shock or injury, which is paramount when dealing with electrical equipment.

The other steps, while important in various contexts, do not take precedence over the act of ensuring the working environment is safe. Notifying a supervisor is a good practice but does not impact immediate personal safety. Testing the motor for power should only occur after it has been safely locked out to avoid potential harm. Checking the motor's warranty may be useful for addressing repair costs or eligibility but is not a safety concern and does not contribute to immediate safe repair practices.