ABB RET670 Commissioning Manual page 202

Section 11
Testing functionality by secondary injection
196
1. Inject current 20% bigger than the set overcurrent pickup level under setting
parameter IOC> (for example, 1.2 · 1.35 · 0.587A = 0951A at 50Hz for this
SCB) in phase L1 only.
2. Check that function binary output signals STOCL1 and STOC are set to one.
3. Check that function binary output signals TROC and TRIP are set to one after
the set time under parameter tOC (that is, 30s for this SCB) has expired.
4. If any of these signals are used for tripping, signaling and/or local/remote
indication check that all relevant contacts and LEDs have operated and that
all relevant GOOSE messages have been sent.
5. Check that service value from the function for current in phase L1, on the
local HMI under Main menu/Test is approximately 476A (that is, 0.951A ·
(500/1) = 476A).
6. Stop injection of all currents (that is, set all currents back to 0A).
7. Check that all above mentioned function binary output signals now have
logical value zero.
8. Repeat above steps 1-7 for phase L2 and phase L3.
Note that the operation of this feature is based on current peak
value. That means that this overcurrent function is also able to
operate for the same current magnitude but for different injected
frequencies. If required repeat this injection procedure for example
for the 3rd harmonic by just simply injecting 3 · 50 = 150Hz
currents with the same magnitude. Obtain results shall be the same.
Undercurrent feature
1. Inject SCB rated current (that is, 0.587A at 50Hz for this SCB) in all three
phases.
2. Lower phase L1 current 10% under the set value for setting parameter IUC<
(that is, 0.9 · 0.7 · 0.587A = 0.370A at 50Hz for this SCB).
3. Check that function binary output signals STUCL1 and STUC are set to one.
4. Check that function binary output signals TRUC and TRIP are set to one after
the set time under parameter tUC (for example, 5s for this SCB) has expired.
5. If any of these signals are used for tripping, signaling and/or local/remote
indication check that all relevant contacts and LEDs have operated and that
all relevant GOOSE messages have been sent.
6. Check that service value from the function for current in phase L1, on the
local HMI under Main menu/Test is approximately 185A (that is, 0.370A ·
(500/1) = 185A).
7. Stop injection of all currents (that is, set all currents back to 0A).
8. Check that all above mentioned function binary output signals now have
logical value zero because they will be automatically blocked by operation of
built-in reconnection inhibit feature.
9. Repeat above steps 1-8 for phase L2 and phase L3.
1MRK 504 165-UEN A
GUID-5C2ED7D0-9BE3-40DC-82C0-C351878D4568 v2
Transformer protection RET670 2.2 IEC
Commissioning manual