Westinghouse KRD-4, Installation, Operation, & Maintenance Instruction

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TYP E K RD-4 DI R ECTIONAL OVERCURRENT
GROUND R ELAY
S E T T I N G S
Overcurrent Unit (I)
The only setting required is the pickup current
setting which is made by means of the connector
screw located on the tap plate. By placing the con­
nector screw in the desired tap , the relay will just
clo se its contacts at the tap value current.
If adjustment of pick-up current in between tap
settings is desired insert the tap screw in the next
lowest tap setting and adj ust the spring as de scribed.
It should be noted that this adj ustment results in a
slightly different time characteristic curve and bur­
den.
For carrier relaying the carrier trip overcurrent
unit located in the type KRD-4 relay should be set
higher than the carrier start overcurrent unit located
in the type KA-4 relay at the opposite end of the line.
CAUTION:
Since the tap block connector screw car­
ries operating current, be sure that the screw is
turned tight.
In order to avoid opening the current transformer
circuits when changing taps under load, connect the
spare tap screw in the desired tap po sition before
removing the other tap screw from the original tap
position.
ENERGY REQUIREMENTS
BURDEN DATA OF OP ERATING CURRENT CIRCUIT -
60
CYCLES
AMP ERE VA AT TAP
P . F .
ANGLE
*
TAP VA AT
5
AMPS
P . F. ANGL E
RANGE
VALUE
�
�
. 5 . 23 54°
47
52°
. 75 . 5 2 54° 36 52. 5°
1.0 .94 54° 3 1 53°
. 5- 2 1. 25 1 . 56 54° 28 53. 5°
1 . 5 2 . 1 7
54° 26 . 5
54°
2 . 0 3. 88
54° 24
55°
1 . 0 1 . 3
52°
3 1 . 5 5 1°
1 . 5 2.85 52°
27 . 3
5 1 . 5°
*
2.0 5.2 52° 25. 0 52°
1-4 2 . 5
7 . 7 5
52°
24. 2
52.5°
3.0 1 1 . 4 52° 23. 8
53
4.0 10.6
52° 23 . 3
53 . 5°
4
5. 6 43 ° 6 1 0 t 53°
6 10.8
46°
570 t 54°
8 17 .6 47° 56 0 t 54°
4- 16 9 22.5
48 °
55 0t 55°
1 2
39 . 5 50°
550 t
56°
16 69 52° 550t
56°
10 28 49° 545 t
50°
15
61
5 1 °
540 t 5 1°
10-40
20
1 08 53° 535 t 52°
25 169 54° 530 t
53°
30 252 56° 525 t
53°
40 432 57° 525 t
53°
t
VA at
50
Amperes.
7
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