41-133S
14
Directional Overcurrent Ground Relays
Types IRP, IRC and IRD
ENERGY REQUIREMENTS
TIME OVERCURRENT UNITS: TYPE IRD-2, IRC-2, IRP-2,
VOLT AMPERES
‡
Ampere
Range
TAP
Continuous
Rating
(Amperes)
One Second
Rating
†
(Amperes)
Power
Factor
Angle
φ
At
Minimum
Tap Value
Current
At 3 Times
Minimum
Tap Value
Current
At 10 Times
Minimum
Tap Value
Current
At 20 Times
Minimum
Tap Value
Current
0.5
0.6
0.8
1.0
1.5
2.0
2.5
2.0
2.5
3.0
3.5
4.0
5.0
6.0
4.0
5.0
6.0
7.0
8.0
10.0
12.0
.91
0.96
1.18
1.37
1.95
2.24
2.50
3.01
4.0
4.4
4.8
5.2
5.6
6.0
7.3
8.0
8.8
9.6
10.4
11.2
12.0
28
28
28
28
28
28
28
110
110
110
110
110
110
110
230
230
230
230
230
230
230
58
57
53
50
40
36
29
59
55
51
47
45
41
37
65
50
47
46
43
37
34
4.8
4.9
5.0
5.3
6.2
7.2
7.9
5.04
5.13
5.37
5.53
5.72
5.90
6.54
4.92
5.20
5.34
5.53
5.86
6.6
7.00
39.6
39.8
42.7
45.4
54.4
65.4
73.6
38.7
39.8
42.2
44.0
46.0
50.3
54.9
39.1
42.0
44.1
45.8
49.9
55.5
62.3
256
270
308
348
435
580
700
262
280
312
329
360
420
474
268
305
330
364
400
470
528
790
815
1024
1220
1740
2280
2850
800
920
1008
1120
1216
1500
1800
848
1020
1128
1260
1408
1720
2064
0.5/2.5
2/6
4/12
Thermal capacities for short times other than one second may be calculated on the basis of time being inversely proportional
Degrees current lags voltage at tap value current.
†
φ
to the square of the current.
Voltages taken with high impedance type voltmeter
‡