Siemens SENTRON 3VL series - Page 144

Technical data
11.4 Derating factors
3VL IEC molded case circuit breakers
144 System Manual, 11/2013, 110 0110 - 02 DS 03
Plug-in or withdrawable version:
Table 11- 17 Derating factors thermal-magnetic overcurrent releases (plug-in or withdrawable version)
Molded
case circuit
breaker
Release
Thermal-magnetic TM
Coefficient
at
From [A]
To [A]
40 °C
50 °C
60 °C
70 °C
VL160X
16
40
1
1
1
1
VL160 &
VL160X
50
100
1
1
1
1
125
160
1
0,9
0,9
0,9
VL250
200
250
1
0,9
0,9
0,9
VL400
200
250
1
1
1
1
315
400
1
0,9
0,9
0,9
VL630
315
400
1
1
1
1
500
630
1
0,85
0,85
0,85
Example for VL250:
● I
n
= 200 A at 50 °C
● Ambient temperature = 60 °C
1. Fixed-mounted version:
I
n
= 200 x 0.93
1)
= 186 A
Set I
R
to the next lowest value -> I
R
= 0.9 = 180 A
2. Plug-in or withdrawable version:
I
n
= 200 x 0.93
1)
x 0.9
2)
= 167 A
-> Calculation of overall derating = 0.93 x 0.9 = 0.837
-> Set I
R
to the next lowest value -> I
R
= 0.8 = 160 A
1)
Derating factor from the table "Derating factors of thermal-magnetic overcurrent releases"
2)
Coefficient for plug-in or withdrawable version from the table "Derating factors for thermal-
magnetic overcurrent releases (plug-in or withdrawable version)"