To verify the settings in the most common back-up trip mode 1 out of 3, it is sufficient to
test phase-to-ground faults.
At mode 2 out of 4 the phase current setting, Pickup_PH can be checked by single-phase
injection where the return current is connected to the summated current input. The value
of residual (ground fault) current IN set lower than Pickup_PH is easiest checked in back-
up trip mode 1 out of 4.
6.3.9.1 Checking the phase current operate value,
Pickup_PH
Check the current level IP> where setting FunctionMode=Current and setting
BuTripMode=1 out of 3 or 2 out of 4 as set under Main menu/Settings/IED Settings/
Current/CCRBRF(50BF)/CCRBRF:1.
1. Apply the fault condition, including INITIATION of CCRBRF (50BF), with a
current below set Pickup_PH.
2. Repeat the fault condition and increase the current in steps until a trip occurs.
3. Compare the result with the set Pickup_PH.
4. Disconnect AC and INITIATE input signals.
Note! If NoIPickupcheck or Retrip off is set, only back-up trip can be
used to check set Pickup_PH.
6.3.9.2 Checking the residual (ground fault) current operate value
Pickup_N
set
below
Pickup_PH
Check the low set Pickup_N current where setting FunctionMode = Current and setting
BuTripMode = 1 out of 4 as set under Main menu/Settings/IED Settings/Current/
CCRBRF(50BF)/CCRBRF:1.
1. Apply the fault condition, including INITIATION of CCRBRF (50BF), with a
current just below set IN>Pickup_N.
2. Repeat the fault condition and increase the current in steps until trip appears.
3. Compare the result with the set Pickup_N.
4. Disconnect AC and INITIATION input signals.
6.3.9.3 Checking the re-trip and back-up times
The check of the set times can be made in connection with the check of operate values
above.
Section 6 1MRK 505 293-UUS A
Testing functionality
60
Commissioning manual
To Next Page
Loading...
Need help?
General
