Integration in power distribution equipment 
  7.3 Derating in the power distribution equipment 
3WA1 air circuit breaker 
Equipment Manual, 02/2023, 92310000002-06 
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7.3  Derating in the power distribution equipment 
7.3.1  Overview 
The following tables provide information about the rating of the 3WA circuit breaker 
within the power distribution equipment. The data presented here is a summary of 
computer simulations and tests actually performed. They represent guide values for both 
fixed-mounted and withdrawable breakers. 
Note 
The derating specifications are not a replacement for an integration test according to 
IEC
 61439. 
The derating values were determined within the following constraints: 
•  Minimal conductor cross-section of copper busbars, as specified in the 3WA catalog 
•  Control panels with internal separation according to shape 4 
•  Installed power loss of 100 W provided for auxiliary and control components in the 
control panel 
If copper busbars with a greater cross-section or control panels with internal separation 
up to shape 2b are used, the derating values improve significantly. 
7.3.2  Derating 3WA11 
The following tables show the derating for size 1, installed in a control panel. 
 A circuit breaker is currently (status in 2022) not yet integrated in the 
Siemens power distribution equipment. The derating values are therefore not yet 
available for installation of the size 1 3WA circuit breaker 2500
 A in the power