Hitachi RET670 User Manual

For example, if the measured voltage jumps from the rated value to 0.8 times the set start
voltage level and time multiplier k1 is set to 0.05 s (default value), then the TR1 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 of the function.
Extended testing
M13796-35 v8
The tests above can be repeated for 2 out of 3 and for 3 out of 3 operation mode.
11.6.1.2 Completing the test
M13796-25 v5
Continue to test another function or end the test by changing the TESTMODE setting to Off. Restore
connections and settings to the original values, if changed for testing purposes.
11.6.2 Two step overvoltage protection OV2PTOV
M13806-2 v6
Prepare the IED for verification of settings as outlined in section
"Requirements" and
section "Preparing for test" in this chapter.
11.6.2.1 Verifying the settings
M13806-9 v2
Verification of single-phase voltage and time delay to operate for Step 1
M13806-50 v10
1. Apply single-phase voltage below the set value U1>.
2. Slowly increase the voltage until the ST1 signal appears.
3. Note the operate value and compare it with the set value U1>.
The operate value in secondary volts is calculated according to the following
equations:
For phase-to-earth measurement:
U UBase VT
VTprim
1
100
3
>
× ×
sec
IECEQUATION2426 V1 EN-US (Equation 103)
For phase-to-phase measurement:
U
UBase
VT
VTprim
1
100
>
× ×
sec
IECEQUATION2427 V1 EN-US (Equation 104)
4. Decrease the voltage slowly and note the reset value.
5. Set and apply about 20% higher voltage than the measured operate value for one phase.
6. Measure the time delay for the TR1 signal and compare it with the set value.
7. Check the inverse time delay by injecting a voltage corresponding to 1.2 × U1>.
8. Repeat the test to check the inverse time characteristic at different over-voltage levels.
9. Repeat the above described steps for Step 2 of the function.
11.6.2.2 Extended testing
GUID-BE4B4A36-CCEE-4020-B7DC-6A83A43D11F5 v2
1. The tests above can be repeated for 2 out of 3 and for 3 out of 3 operation mode.
1MRK 504 165-UEN Rev. K Section 11
Testing functionality by secondary injection
Transformer protection RET670 195
Commissioning manual
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Hitachi RET670 Specifications

General

Brand	Hitachi
Model	RET670
Category	Control Systems
Language	English