Cycles
5
5
5
5
5
5
5
Sec
2
2
2
2
2
2
2
KV rms
3.85
4.0
6.6
11.5
11.5
11.5
23
36
49
41
23
36
48
35
kA rms
36
49
41
23
36
48
35
Appendix
Table A-1a
Type 3AH Circuit Breaker Ratings (Historic “Constant MVA” Rating Basis)
Circuit Breaker Type
These ratings are in accordance with the following standards:
ANSI C37.04-1979
Standard Rating Structure for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis
ANSI C37.06-1987
AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis- Preferred Ratings and Related Required Capabilities
ANSI C37.09-1979
Standard Test Procedure for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis
ANSI C37.010-1979
Application Guide for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis
Measured Parameter
Units
General
Related
Required
Capabilities
Rated
Values
Nominal Voltage Class
Nominal 3-Phase MVA Class
(8)
Maximum Design Voltage ( V )
(2)
Voltage Range Factor ( K )
(3)
Rated
Voltage
Power Frequency
Lightning Impulse (BIL)
Continuous
(2)
Short-Circuit (at rated maximum
design voltage) ( I )
(4)
(5)
(9)
Interrupting Time
Permissible Tripping Delay ( Y )
Rated Maximum Design Voltage (V)
divided by K ( = V/K )
Max. Sym Interrupting ( K x I )
(6)
Short-Time Current ( K x I ) (3 seconds)
Asymmetrical ( 1.6 x K x I )
(7)
Peak ( 2.7 x K x I )
(7)
Insulation
Levels
Rated
Current
Current
Withstand
Voltage Levels
Closing
and
Latching
(Momentary)
5-3AF-
250
5-3AH-
350
7-3AH-
500
15-3AH-
500
15-3AH-
750
15-3AH-
1000
38-3AH-
1500
kV
4.16
4.16
7.2
13.8
13.8
13.8
38
MVA
250
350
500
500
750
1000
1500
kV rms
4.76
4.76
8.25
15.0
15.0
15.0
38
——
1.24
1.19
1.25
1.30
1.30
1.30
1.65
kV rms
19
19
36
36
36
36
80
kV crest
60
60
95
95
95
95
150
A rms
1200
2000
1200
2000
3000
1200
2000
3000
1200
2000
3000
1200
2000
1200
2000
3000
1200
2000
3000
kA rms
sym
kA rms
sym
29
41
33
18
28
37
21
kA rms
kA peak
Footnotes
1.
High close and latch (momentary) rating available for special application
2.
Maximum voltage for which the circuit breaker is designed, and the upper limit for operation.
3.
K is the ratio of the rated maximum design voltage to the lower limit of the range of operating voltage in which the required
symmetrical and asymmetrical interrupting capabilites vary in inverse proportion to the operating voltage.
4.
To obtain the required symmetrical interrupting capability of a circuit breaker at an operating voltage between 1/K times rated
maximum design voltage and rated maximum design voltage, the following formula shall be used:
Required Symmetrical Interrupting Capability = Rated Short-Circuit Current ( I ) X [ ( Rated Maximum Design Voltage ) / ( Operating
Voltage ) ]
For operating voltages below 1/K times rated maximum design voltage, the required symmetrical interrupting capability of the
circuit breaekr shall be equal to K times rated short-circuit current.
5.
Within the limitations stated in ANSI C37.04-1979, all values apply to polyphase and line-to-line faults. For single phase-to-ground
faults, the specific conditions stated in clause 5.10.2.3 of ANSI C37.04-1979 apply.
6.
Current values in this row are not to be exceeded even for operating voltage below 1/K times rated maximum design voltage. For
operating voltages between rated maximum design voltage and 1/K times rated maximum design voltage, follow footnote 5 above.
7.
Current values in this row are independent of operating voltage up to and including rated maximum design voltage.
8.
“Nominal 3-Phase MVA Class” is included for reference only - this information is not listed in ANSI C37.06-1987.
9.
Standard duty cycle is CO - 15s - CO
58
78 opt
(1)
78
66
77 opt
(1)
37
58 opt
(1)
58
77 opt
(1)
77
56
97
132 opt
(1)
132
111
130 opt
(1)
62
97 opt
(1)
97
130 opt
(1)
130
95
30
