The reverse phase alarm pilot light for electric pumps should be:

• A. On
• B. Blinking
• C. Not installed
• D. Off

Answer: (D)

In a three-phase electric pump, the phase sequence must be correct for the motor to rotate in the intended direction. A reverse-phase alarm pilot light serves as a warning if the phases are out of order. During normal operation with the correct phase sequence, there is no fault to signal, so the alarm indicator stays off. The light would only come on to alert you to fix the phase wiring or supply if reverse rotation is detected. If the light were on, it would mislead you into thinking there’s a fault when there isn’t; blinking could indicate an intermittent issue; and not installing this indicator would remove a crucial safety alert. Therefore, it should be off.