Voltage Monitor Relay

Sold by Magco Electrical Limited · Accra Metropolitan

How It Works When the three-phase supply is connected correctly (proper sequence and all phases present at adequate voltage), the internal relay energizes immediately. Its normally open (NO) contacts close to allow the control circuit (e.g., contactor coil) to operate, permitting the motor or machine to run. If a fault occurs (phase loss, phase reversal, or severe undervoltage), the relay de-energizes after a short delay (typically 0.5–3 seconds), opening the contacts to cut power and stop the equipment. This prevents motor damage, overheating, or reverse rotation. The diagram on the label illustrates the internal contact logic between the terminals.