Advertisement
CO-8 INVERSE TIME AND CO-9 VERY INVERSE TIME RELAYS
AMPERE
CONTINUOUS
RANGE
TAP
RATING
(AMPERES)
0.5
2.7
0.6
3.1
0.8
3.7
0.5/2.5
1.0
4.1
1.5
5.7
2.0
6.8
2.5
7.7
1.0
4.5
1.2
5.5
1.5
6.0
2.0
7.7
2.5
9.5
3.0
10.0
1/12
3.5
12.0
4.0
13.5
5.0
15.0
6.0
17.5
7.0
20.5
8.0
22.5
10.0
23.5
12.0
26.5
0.5
1.7
0.6
1.9
0.8
2.2
0.5/2.5
1.0
2.5
1.5
3.0
2.0
3.5
2.5
3.8
1.0
3.5
1.2
4.0
1.5
5.5
2.0
8.5
2.5
10.0
3.0
12.5
1/12
3.5
14.0
4.0
15.0
5.0
17.0
6.0
18.5
7.0
20.0
8.0
21.5
10.0
25.0
12.0
28.0
Thermal capacities for short times other than one second may be calculated on the basis of times being inversely proportional to
the square of the current
øDegrees current lags voltage at tap value current
* * Voltages taken with Rector type voltmeter
Courtesy of NationalSwitchgear.com
ENERGY REQUIREMENTS
ONE SECOND POWER
TAP VALUE
CURRENT
RATING
FACTOR
(AMPERES)
(AMPERES)
88
72
88
71
88
69
88
67
88
62
88
57
88
53
88
73
88
73
88
72
88
69
88
68
230
67
230
66
230
65
230
63
460
60
460
57
460
55
460
48
460
45
CO-11 EXTREMELY INVERSE TIME RELAY
56
36
56
34
56
30
56
27
56
22
56
17
56
16
56
30
56
29
56
26
56
25
56
24
230
33
230
31
230
29
230
25
460
22
460
20
460
19
460
14
460
10
60 HERTZ VOLT AMPERES**(x
AT
AT 3 TIMES
TAP VALUE
CURRENT
∆
∆
(
= 0.86)
(
= 0.88)
3.38
21
2.38
21
2.40
21.1
2.42
21.2
2.51
22
2.65
23.5
2.74
24.8
2.33
20
2.33
20
2.35
20.1
2.35
20.2
2.36
20.3
2.37
20.4
2.38
20.9
2.40
21.0
2.40
21.0
2.47
21.6
2.51
21.8
2.52
22.2
2.77
24.5
2.94
25.4
0.72
6.54
0.75
6.80
0.81
7.46
0.89
8.30
1.13
10.04
1.30
11.95
1.48
13.95
0.82
7.4
0.90
8.0
0.97
8.6
1.00
8.9
1.10
9.0
0.87
8.0
0.88
8.2
0.94
8.7
1.10
10.0
1.25
11.5
1.40
12.3
1.50
14.0
1.9
18.3
2.4
23.8
I.L. 41-100J
∆
FOR 50 HZ)
AT 10 TIMES
AT 20 TIMES
TAP VALUE
TAP VALUE
CURRENT
CURRENT
∆
∆
(
= 0.9)
(
= 0.91)
132
350
134
365
142
400
150
440
170
530
200
675
228
800
135
347
135
361
142
383
145
412
146
415
149
420
153
450
157
460
164
500
170
525
180
600
192
672
230
830
258
960
71.8
250
75.0
267
84.0
298
93.1
330
115.5
411
136.3
502
160.0
610
82
300
87
324
93
350
96
380
96
377
88
340
88
340
96
366
110
435
120
478
135
560
160
648
210
900
276
120
11
Advertisement
