ABB RET670 Commissioning Manual page 172

Section 10
Testing functionality by secondary injection
This means that if the measured phase current jumps from 0 to 2 times the set trip level and
time multiplier k is set to 1.0 s (default value), then the TROC and TRIP signals will trip after a
time delay equal to 13.5 s ± tolerance.
Taking into account the above explanation, inject the voltages related to the last part of the
characteristic and inject a current IA 200% higher than the set operation level, and check the
trip time delay.
10. Check the pickup and trip information that are stored in the event menu.
11. The previous step 8 or 9 may be repeated also for the first and second section of the
characteristic.
12. Supply the IED with symmetric three-phase voltages at their rated values. Go to Main menu/
Settings/IED Settings/Current protection/VoltageRestOverCurr(51V,2(I>/V<))/
VRPVOC(51V,2(I>/V<)):1/Undervoltage and set the setting
activate the undervoltage stage.
13. Slowly decrease the voltage in two phases simultaneously, until the STUV and PICKUP signals
appear.
14. Note the trip value. The set trip value in secondary volts is calculated according to the
following equation:
Pickup Volt VBase
ANSIEQUATION2436 V2 EN-US
15. Increase slowly the applied voltages of the previous two phases and note the reset value.
16. Check that the trip output of the relay is connected to the input channel of the test in order
to stop the injection and measure the trip time.
17. Inject symmetric three-phase voltages at their rated value and check that the STUV and
PICKUP signals reset as well as the trip signals of the function block (TRIP and TRUV).
18. Instantaneously decrease the voltage in two phases simultaneously to a value 20% lower
than the set trip value (take into account the previous note if VRPVOC is configured in ACT
with the undervoltage seal-in feature).
19. Measure the definite time delay for the TRUV and TRIP signals and compare it with the set
value
20. Check that pickup and trip information is stored in the event menu.
166
tDef_OC is set to a value different from 0 s, then this time delay is added to
If
the one that is defined by the IDMT characteristic.
_ VT
× ×
100 VTprim
3
If the VRPVOC function is used as an overcurrent protection with
undervoltage seal-in, it is necessary to first inject sufficient current to
activate the STOC signal before the under-voltage step is allowed to trip. In
order to achieve that, apply symmetric three-phase voltages at their rated
value and then inject a current IA that is 200% higher than the set tripping
level. Then slowly decrease the voltage in two phases simultaneously, until the
STUV and PICKUP signals appear.
tDef_UV .
sec
1MRK 504 154-UUS B
Operation_UV = Enabled to
(Equation 95)
Commissioning manual