The AUTO XFER switchlight FAIL light indicates what?

The AUTO XFER switchlight FAIL light indicates what?

• A. AUTO XFER was inhibited due to a fault on AC Bus 1 or 2
• B. Auto transfer is active
• C. The system is ready for automatic transfer
• D. A fault on the DC bus

Answer: (A)

Automatic transfer between the two AC buses relies on both buses being healthy. The FAIL light for AUTO XFER indicates that auto transfer has been inhibited because a fault has been detected on AC Bus 1 or AC Bus 2. When this light is on, the system cannot automatically switch power sources and requires troubleshooting or manual action. If auto transfer were actively functioning, that fail indicator wouldn’t be lit. A fault on the DC bus would trigger different indicators specific to the DC system, not this AC-bus fail light.

Automatic transfer between the two AC buses relies on both buses being healthy. The FAIL light for AUTO XFER indicates that auto transfer has been inhibited because a fault has been detected on AC Bus 1 or AC Bus 2. When this light is on, the system cannot automatically switch power sources and requires troubleshooting or manual action. If auto transfer were actively functioning, that fail indicator wouldn’t be lit. A fault on the DC bus would trigger different indicators specific to the DC system, not this AC-bus fail light.