Appendix
Table A-1b
Type 3AH Circuit Breaker Ratings (New “Constant kA” Rating Basis)
Circuit Breaker Type
ANSI C37.04-1999
Standard Rating Structure for AC High-Voltage Circuit Breakers
ANSI C37.06-2000
AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis- Preferred Ratings and Related Required Capabilities
ANSI C37.09-1999
Standard Test Procedure for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis
ANSI C37.010-1999
Application Guide for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis
Rated Values
Units
5-3AH-
31
5-3AH-
40
5-3AH-
50
7-3AH-
40
15-3AH-
20
15-3AH-
25
15-3AH-
31
15-3AH-
40
15-3AH-
50
27-3AH-
25
38-3AH-
31.5
Maximum Design Voltage ( V )
(1)
Voltage Range Factor ( K )
(2)
Withstand
Voltage Levels
Power Frequency
Lightning
Impulse (BIL)
Continuous
(3)
kV rms
——
kV rms
kV crest
A rms
kA rms
sym
ms
Cycles
Sec
kA rms
sym
%
kA rms
kA rms
kA peak
Short-Circuit ( I )
(4)
(5)
Interrupting Time
Permissible Tripping Delay ( Y )
Max. Sym Interrupting ( I )
% dc Component
Short-Time Current ( I ) (3 seconds)
Closing & Latching (Momentary)
Asymmetrical ( 1.55 x I )
Closing & Latching (Momentary)
Peak ( 2.6 x I )
1200
2000
2
2
2
2
2
2
2
2
2
2
2
31.5
40
50
40
20
25
31.5
40
50
25
31.5
47
47
47
47
47
47
47
47
47
47
47
31.5
40
50
40
20
25
31.5
40
50
25
31.5
49
62
78
62
31
39
49
62
78
39
49
82
104
130
104
52
65
82
104
130
65
82
4.76
4.76
4.76
8.25
15.0
15.0
15.0
15.0
15.0
27.0
38.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
19
19
19
36
36
36
36
36
36
60
80
60
60
60
95
95
95
95
95
95
125
150
31.5
40
50
40
20
25
31.5
40
50
25
31.5
83
5
1200
2000
3000FC
1200
2000
3000FC
1200
2000
3000FC
1200
2000
1200
2000
1200
2000
1200
2000
3000FC
1200
2000
3000FC
1200
2000
3000FC
1200
2000
3000FC
83
5
83
5
83
5
83
5
83
5
83
5
83
5
83
5
83
5
83
5
Footnotes
1.
Maximum voltage for which the circuit breaker is designed, and the upper limit for operation.
2.
K is listed for informational purposes only. For circuit breakers rated on a “kA basis”, the Voltage Range Factor is 1.0.
3.
3000FC indicates that fan cooling may be required in the switchgear structure to achieve this rating.
4.
All values apply to polyphase and line-to-line faults.
5.
Standard duty cycle is O - 0.3s - CO - 15s - CO.
31
