Siemens 3AH Instructions, Installation, Operation, Maintenance page 30

Appendix
Table A-1a
Type 3AH Circuit Breaker Ratings (Historic "Constant MVA" Rating Basis)
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
Nominal Voltage Class
General
Nominal 3-Phase MVA Class
Maximum Design Voltage ( V )
Rated
Voltage
Voltage Range Factor ( K )
Insulation
Withstand
Levels
Voltage Levels
Rated
Values
Continuous
Rated Short-Circuit (at rated maximum
Current
design voltage) ( I )
Interrupting Time
Permissible Tripping Delay ( Y )
Rated Maximum Design Voltage (V)
divided by K ( = V/K )
Current
Max. Sym Interrupting ( K x I )
Related
Required
Short-Time Current ( K x I ) (3 seconds)
Capabilities
Closing
Asymmetrical ( 1.6 x K x I )
and
Latching
Peak ( 2.7 x K x I )
(Momentary)
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
Units
kV
(8) MVA
(2) kV rms
(3) ——
Power Frequency kV rms
Lightning Impulse (BIL) kV crest
A rms
(2)
kA rms
sym
(4) (5) (9)
Cycles
Sec
KV rms
kA rms
(6)
sym
kA rms
(7) kA rms
kA peak
(7)
Circuit Breaker Type
5-3AH- 7-3AH-
5-3AF- 15-3AH-
350 500
250
4.16 4.16 7.2
250 350 500
4.76 4.76 8.25
1.24 1.19 1.25
19 19 36
60 60 95
1200 1200
1200
2000 2000
2000
3000 3000
29 41 33
5 5 5
2 2 2
3.85 4.0 6.6
36 49 41
36 49 41
58 66
78
78 opt (1) 77 opt (1) 58 opt
97 111
132
132 opt (1) 130 opt (1)
97 opt
15-3AH- 15-3AH- 38-3AH-
500 750 1000 1500
13.8 13.8 13.8 38
500 750 1000 1500
15.0 15.0 15.0 38
1.30 1.30 1.30 1.65
36 36 36 80
95 95 95 150
1200 1200
1200
1200
2000
2000 2000
2000
3000 3000 3000
18 28 37 21
5 5 5 5
2 2 2 2
11.5 11.5 11.5 23
23 36 48 35
23 36 48 35
37 58
56
77
(1) 77 opt (1)
97
62
95
130
(1) 130 opt (1)
30