17
4.3 Synchronization Diagnostics
Synchronization Diagnostics frequency variations from the
nominal value are automatically accepted and compensated if:
(Nominal Frequency -1.4 Hz) <Frequency measured< (Nominal
Fre1.4 Hz)
Synchronization Diagnostics inhibit the Ready condition when
the signal from the voltage sensor is less than 100mV (corre-
sponding to 1.7 kV on the bus bars).
Synchronization Diagnostics inhibit the Ready condition when
the harmonic content is too high.
Synchronization diagnostics cannot detect an imbalance
between the three-phase systems and cannot prevent an
operation if this imbalance leads to a significant error in
power contact timing.
An additional protection to prevent this type of operation
should be installed in the up-stream CB or in the system.
4.4 Diagnostics Table
DS1
Pressure Sensor
Description
Actions
Status
Ready
Alarm
OK
Warming
Low
OPEN
Ready
–
OK
–
–
DS1 is ready to perform a
close operation.
–
OPEN
Ready
–
–
Warning
–
DS1 is ready to perform
a close operation. Check
'Actions'.
Check pressure level. If it is not ok, plan a refill.
If it is ok and the Warning signal persists, contact
ABB and plan a check.
DS1 can still perform a close and open operation.
OPEN
–
–
OK
–
–
DS1 is not ready to
perform a close operation.
Check 'Actions'.
This condition occurs when there is no voltage on
busbar side, at start up or when the Interlock loop
is open.
DS1 can perform open and close operations by
providing power to Upstream CB interlock input.
If this condition occurs when voltage is present
on busbar side, check the interlock loop. If it is
closed, contact ABB and plan a check.
OPEN
–
–
–
Warning
Low
DS1 is not ready to
perform a close operation.
Check 'Actions'.
Check pressure level. If it is not ok, plan a refill.
If it is ok and this condition persits, contact ABB
and plan a check.
OPEN
–
ALARM
OK
–
–
DS1 is not ready to
perform a close operation.
DS1 reached the final position after an open
operation, but an anomaly was detected during
the operatios.
Contact ABB and plan a check.
Incoherent –
ALARM
OK
–
–
DS1 is not ready to
perform a close operation.
DS1 is in alarm mode.
Check ‘Actions’.
Pole position is not coherent.
Contact ABB and plan a check.
CLOSE
Ready
–
OK
–
–
DS1 is ready to perform a
close operation.
–
CLOSE
Ready
–
–
Warning
–
DS1 is ready to perform a
close operation.
Check ‘Actions’.
Check pressure level. If it is not ok, plan a refill.
If it is ok and the Warning signal persists, contact
ABB and plan a check.
DS1 can still perform a close and open operation.
CLOSE
–
–
OK
–
–
DS1 is not ready to
perform a close operation.
Check ‘Actions’.
This condition occurs when there is no voltage on
busbar side. at start up or when the Interlock loop
is open.
DS1 can perform open and close operations by
providing power to Upstream CB interlock input.
If this condition occurs when voltage is present
on busbar side, check the interlock loop. If it is
closed, contact ABB and plan a check.
CLOSE
–
–
–
Warning
Low
DS1 is not ready to
perform a close operation.
Check ‘Actions’.
Check pressure level. If it is not ok, plan a refill.
If it is ok and this condition persits, contact ABB
and plan a check.
CLOSE
–
ALARM
OK
–
–
DS1 is not ready to
perform a close operation.
DS1 is in alarm mode.
Check ‘Actions’.
DS1 reached the final position after a close
operation, but an anomaly was detected during
the operatios.
Contact ABB and plan a check.
Figure 12. DS1 Diagnostic indications
Provided
by
Northeast
Power
Systems,
Inc.
(NEPSI)