ABB RET650 Series Commissioning Manual page 68

Section 7
Testing functionality
1. Check that the IED settings are appropriate, especially the PICKUP value, the definite time
delay and the
2. Supply the IED with three-phase voltages at their rated values.
3. Slowly decrease the voltage in one of the phases, until the PICKUP signal appears.
4. Note the operate value and compare it with the set value.
For phase-to-ground measurement:
Vpickup
ANSIEQUATION2430 V1 EN-US
For phase-to-phase measurement:
Vpickup
ANSIEQUATION2431 V1 EN-US
5. Increase the measured voltage to rated load conditions.
6. Check that the PICKUP signal resets.
7. Instantaneously decrease the voltage in one phase to a value about 20% lower than the
measured operate value.
8. Measure the time delay for the TRIP signal, and compare it with the set value.
9. Check the inverse time delay by injecting a voltage corresponding to 0.8 × Vpickup<.
( )
t s
ANSIEQUATION2428 V1 EN-US
where:
t(s)
TD1
V
Vpickup< Set pickup voltage for step 1
For example, if the measured voltage jumps from the rated value to 0.8 times the set pickup
voltage level and time multiplier TD1 is set to 0.05 s (default value), then the TRST1 and TRIP
signals operate at a time equal to 0.250 s ± tolerance.
10. The test above can be repeated to check the inverse time characteristic at different voltage
levels.
11. Repeat the above-described steps for step 2.
62
1 out of 3 operation mode.
The operate value in secondary volts is calculated according to the following
equations:
<
VBase VT sec
´ ´
100 VTprim
3
<
VT sec
´ ´
VBase
100 VTprim
For example, if the inverse time curve A is selected, the trip signals TRST1 and
TRIP operate after a time corresponding to the equation:
TD 1
=
æ ö
V
-
1
ç ÷
<
Vpickup
è ø
Operate time in seconds
Settable time multiplier of the function for step 1
Measured voltage
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1MRK 504 136-UUS B
(Equation 10)
(Equation 11)
(Equation 12)
Transformer protection RET650
Commissioning manual