Basler BE1-CDS220, Instruction Manual

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13-12 Testing And Maintenance BE1-CDS220
time. It is only necessary to apply one phase per input to verify response and correctly entered settings.
For example, apply A phase for CT circuit 1 and 2 for group 0, B phase for CT circuit 1 and 2 for group 1,
etc. to verify all phases and all set points.
Step 2. Calculate test points for minimum-pickup test.
•
Calculate the test points using the compensation settings recorded in Step 1 and the appropriate
equations shown in Tables 13-8 through 13-10. Record the calculated test point for each setting
group before running the test.
•
Record the phases that will respond to the test.
Table 13-8. Differential Element Minpu Response to IA Test Current
CT Input Compensation
Element
Angle Comp Ground Source 87A 87B 87C
Wye (None) 0=No Minpu*Tap NA NA
Wye (None) 1=Yes 1.5*Minpu*Tap 3*Minpu*Tap 3*Minpu*Tap
DAB NA
√
3*Minpu*Tap NA
√
3*Minpu*Tap
DAC NA
√
3*Minpu*Tap
√
3*Minpu*Tap
NA
Table 13-9. Differential Element Minpu Response to IB Test Current
CT Input Compensation Element
Angle Comp Ground Source 87A 87B 87C
Wye (None) 0=No NA Minpu*Tap NA
Wye (None) 1=Yes 3*Minpu*Tap 1.5*Minpu*Tap 3*Minpu*Tap
DAB NA
√
3*Minpu*Tap
√
3*Minpu*Tap NA
DAC NA NA
√
3*Minpu*Tap
√
3*Minpu*Tap
Table 13-10. Differential Element Minpu Response to IC Test Current
CT Input Compensation Element
Angle Comp Ground Source 87A 87B 87C
Wye (None) 0=No NA NA Minpu*Tap
Wye (None) 1=Yes 3*Minpu*Tap 3*Minpu*Tap 1.5*Minpu*Tap
DAB NA NA
√
3*Minpu*Tap
√
3*Minpu*Tap
DAC NA
√
3*Minpu*Tap NA
√
3*Minpu*Tap
Step 3. Test minimum pickup.
Slowly ramp up test current until the relay trips. Monitor an appropriate contact per the logic settings and
the trip LED. Record the value. Record if the proper phases targeted and if the test was passed. The
accuracy should be
±
4% or 0.75 milliamperes for 5 ampere units and
±
4% or 25 milliamperes for 1
ampere units.
Phase Differential Restrained Slope Trip
This test will verify the percentage restraint characteristic. Since each current input circuit and phase
protective element was verified in the preceding test, it is only necessary to test and verify the slope
characteristic on one phase element for each setting group.
The restrained slope test requires that you start from a balanced condition. To create the Iop (differential)
current, you will vary one test current upward or downward from this balanced condition. The test point at
which a trip should occur will depend upon whether you set the relay to operate on percent of maximum
restraint current or percent of average restraint current. It will also depend upon whether the Iop is to be
developed by increasing or decreasing one current source from balance. See Figure 13-3 for details.
Step 4. Calculate test starting point (balanced) for restrained slope test.
Step 4-1. Select and record the appropriate test connection from Table 13-11.
Step 4-2. Calculate the balanced starting test currents that are to be applied to each input circuit of the
relay. Use the appropriate equation from Table 13-11, Test Current, and record values before