ABB eVM1 Installation And Service Instructions Manual page 56

Note
54
14.5.6 Additional built-in Functionality
14.5.6.1 Unit Ready Monitoring
The Ready LED on the CB HMI and relative "READY/NOT READY" contacts signal the CB is
Ready to operate when the following conditions are true:
capacitor is charged
WatchDog OK (uP is operative)
detection of correct "CLOSED" and "OPEN" CB status by the position sensors
blocking anomalies status are active (see par. 14.14).
In Unit Not Ready status all Close commands (both local and remote) are ignored. The Open command
is always allowed if energy for opening is sufficient and opening coil continuity is Ok.
The Ready LED on the CB HMI will go off if position sensor indication or coil continuity is lost. It
will flash when the capacitor voltage (i.e. the stored energy) is below the maximum charge level
until there is enough energy for an opening or closing operation.
14.5.6.2 Actuator Coil Supervision
The IED monitors the actuator opening and closing coil continuity. It verifies that both coils are
connected and not interrupted (they are both not in open circuit condition).
When this condition is true, the "Coil OK" LED on the CB HMI goes ON.
When the function becomes false an Anomaly alarm is issued, the No Anomaly LED on the CB
HMI goes ON, the Coil Continuity LED goes OFF and the IED can enter Not Ready status, depending
on the CB position and which coil fails, according to the following cases:
CB position Closed
Coil continuity condition
Closing coil continuity incorrect Unit Ready
Opening coil continuity incorrect Unit Not Ready
Unit in wait state for Open command only Unit does not carry out any command
Unit does not carry out any command
Open
Unit Not Ready
Unit Not Ready
Unit does not carry out any command