Siemens SENTRON 3VL - Page 166

Technical data
12.5 Derating factors
3VL molded-case circuit breakers
166 System Manual, 03/2009, 110 0110 - 02 DS 01
Thermomagnetic overcurrent trip unit, setting values Ir (thermal)
Table 12- 27 Derating factors for low setting values
Circuit
breaker
At 0 °C At 10 °C At 20 °C At 30 °C At 40 °C At 50 °C At 60 °C At 70 °C
VL160X 0,80 0,84 0,88 0,92 0,96 1 1,04 1,08
VL160 0,80 0,84 0,88 0,92 0,96 1 1,04 1,08
VL250 0,80 0,84 0,88 0,92 0,96 1 1,04 1,08
VL400 0,80 0,84 0,88 0,92 0,96 1 1,04 1,08
VL630 0,80 0,84 0,88 0,92 0,96 1 1,04 1,08
Table 12- 28 Derating factors for high setting values
Circuit
breaker
At 0 °C At 10 °C At 20 °C At 30 °C At 40 °C At 50 °C At 60 °C At 70 °C
VL160X 0,65 0,72 0,79 0,86 0,93 1 1,07 1,14
VL160 0,65 0,72 0,79 0,86 0,93 1 1,07 1,14
VL250 0,65 0,72 0,79 0,86 0,93 1 1,07 1,14
VL400 0,65 0,72 0,79 0,86 0,93 1 1,07 1,14
VL630 0,65 0,72 0,79 0,86 0,93 1 1,07 1,14
Example for VL250:
● I
n
= 250 A at 50 °C
● Setting the thermal overcurrent trip unit: 250 A
● Ambient temperature = 20 °C
● Corrected setting = 250 x 0.87 = 217 A