ABB eVM1, Installation And Service Instructions Manual

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COthr
Link Capacitor
I/O Input Level
Capacitor Voltage [V]
Level ‘KO’
Level ‘OK’
Othr
14.5.5.6 Energy Failure Autotrip
The IED monitors the charge of the capacitors, continuously checking the voltage. When the CB is
in the closed position there must be enough energy to carry out the opening operation (O), while if
the CB is open there must be enough energy to close and then to open (CO) it. If there is not
enough energy (level ‘KO’), the CB must be locked in its position or opened if the Energy Failure
Autotrip function is enabled
When Energy Failure Autotrip is enabled it will make the CB open when the external power supply
is shut down or there is an internal energy failure. The Opening operation is typically performed
within 1-2 minutes after auxiliary power failure depending on CB ratings, and the delay is due to
discharging of energy stored in the internal capacitor by the IED.
An Anomaly alarm is issued and the No Anomaly LED on the CB HMI goes ON.
The system is in ‘Energy Failure status’ when the capacitor charge is under the Othreshold (‘KO’
level).
The following behaviour is allowed:
CB position Closed Open
Capacitor Charge
Energy sufficient for O-CO operations Opening allowed Closing allowed
Energy sufficient for CO operations Opening allowed Closing allowed
Energy sufficient for O operations Opening allowed Blocked in open position
Energy insufficient for any operation Blocked in closed position Blocked in open position
or CB immediately opened
14.5.5.7 UnderVoltage
The IED monitors the voltage on UnderVoltage Binary input DI1 and the value is processed.
When the UnderVoltage function is enabled it will make the CB open when an undervoltage condition
is detected; i.e. when the voltage drops below 70% of its nominal value. The UnderVoltage condition
will only be reset when the voltage on DI1 becomes higher than 85% (ref. to IEC 60694.5.8.4).
The nominal voltage value is selected by setting the Dip-Switches S1 ... S4 on the I/O board.
Fig. 38