Siemens SENTRON 3VL160X System Manual page 144

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