Basler BE1-CDS220, Instruction Manual

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13-42 Testing And Maintenance BE1-CDS220
Step 6. Apply 1 multiple of tap current (2 amperes) to both A-phase input 1 and A-phase input 2 (at
180
o
phase relation to input 1).
Step 7. To force a restrained trip at 5 times pickup, you must apply a step change in the current on
input 2 to 8.0 amperes. This value (8.0 amperes) was derived from the following:
I
op
= 5 * I
op trip
I
2
– I = 5 * (I
2
* slope)
I
2
– I
1
= 5 * (I
2
* 0.15)
I
2
– I = 0.75 I
2
0.25 I
2
= 1
I
2
= 4 per unit
I
2
= 8 amperes
Step 8. Apply the step change in current to input 2 and record the time interval between the time the
step change was initiated to the time OUT1 output contact closes (the restrained trip (87RT)).
Step 9. Reduce the current to input 2 until OUT1 contact opens.
Step 10. The time measured in Steps 4 and 8 should be less than those shown in Table 13-28.
Table 13-28. Restrained Trip Operate Times
Function Differential current Time
Restrained trip 1.5 times pu Less than 3 cycles
Restrained trip 5 times pu Less than 2 cycles
Second Harmonic Restraint Verification
Purpose: To verify the operation of the 2
nd
harmonic restraint function of the 87 element.
Reference Commands: SL-87, S(n)-87, S(n)-TAP87, SL-VO, SG-CT
Step 1. Parallel a 60 Hz current source and a second 120 Hz current source to terminals B1, B2
(A-phase, input 1). Reference Figure 13-14.
An ohm-meter or continuity tester may be used to monitor output contact status.
2NDHAR
circuit
monitor
120 Hz
current
source 2
60 Hz
current
source 1
87RT
circuit
monitor
B1 B3 B5 B7
B2 B4 B6 B8
B9 B11 B13 B15
B10 B12 B14 B16
I
A1
I
B1
I
C1
I
G
I
A2
I
B2
I
C2
I
A1
I
B1
I
C1
I
G
I
A2
I
B2
I
C2
Figure 13-14. Connection for Harmonic Restraint Verification
Step 2. Send the commands listed in Table 13-29 to the relay to setup a test of the pickup of the
second harmonic restraint elements.