Cause : Power card supply comes when the supply on the power card is out of range. There are three power supplies generated by the switch mode power supply (SMPS) on the power card: 24 V, 5 V, ±18 V.

• When powered with 24 V DC with the MCB 107 option, only the 24 V and 5 V supplies are monitored.
• When powered with three-phase AC line voltage, all three supplies are monitored.
• Check for a defective power card.
• Check for a defective control card.
• Check for a defective option card.
• If a 24 V DC power supply is used, verify proper supply power.