Technical data
12.5 Derating factors
3VL molded-case circuit breakers
System Manual, 03/2009, 110 0110 - 02 DS 01
165
Plug-in or withdrawable version:
Table 12- 26 Derating factors for electronic trip units (plug-in or withdrawable version)
Trip unit
Thermomagnetic TM
Coefficient
at
Circuit
breaker
From [A] To [A] 40 °C 50 °C 60 °C 70 °C
VL160 63
125
100
160
1
1
1
0,9
1
0,9
1
0,9
VL250 200 250 1 0,9 0,9 0,9
VL400 315 400 1 0,9 0,9 0,9
VL630 630 1 0,85 0,85 0,85
VL800 800 1 0,9 0,9 0,9
VL1250 1000 1250 1 0,95 0,95 0,95
VL1600 1600 1 0,8 0,8 0,8
Example for VL250:
● I
n
= 250 A at 50 °C
● Ambient temperature = 60 °C
● I
n
= 250 x 0.95 = 237 A for fixed-mounted version
● I
n
= 250 x 0.95 x 0.9 = 213 A for plug-in version
● Set I
R
to the next possible value
● I
R
= 0.95 In for fixed-mounted version
● I
R
= 0.8 In for plug-in version
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