Siemens vacuum circuit breaker 38-3AH3 38 kV - Manual (Page 48)

Maintenance
Figure 41: Typical vacuum interrupter contact curve
1 2 5
10 20
100
25 50
31.5
40
10
20
50
100
200
100,000
50,000
20,000
10,000
5,000
2,000
1,000
500
Permissible operating-cycles
Breaking current
symmetrical value
Vacuum interrupters, types VS-30030 and VS-30041
21
19 (40 kA)
18 (31.5 kA)
15 (21 kA)
Note: Right-hand vertical segment of curve is located at the maximum symmetrical
interrupting current rating of the circuit breaker as shown in Table 11: Circuit breaker
operating times (type 3AH3 operator) on page 63 or Table 12: Type 38-3AH3 vacuum
circuit breaker ratings (new "constant kA" ratings basis) on page 64.
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