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What is the derating factor to be applied to a TeSys D (LC1D) contactor when used under continuous thermal current conditions in a high ambient temperature?

The TeSys D (LC1D)  catalogue details the specifications for normal ambient temperature under AC1 duty.

In instances where the ambient temperature (surrounding the product, i.e. inside the enclosure) exceeds the limit quoted in the catalogue, then a derating of the continuous thermal current is applied;

1% derating factor on current per 1°C above 40°C.
For example; 0.8 multiplication factor for 60°C and 0.7 multiplication factor 70°C.

Additional good practice measures when using contactors in high ambient;
  • Avoid side by side (without air gap) mounting.
  • Ensure good air circulation to avoid hot spots.
  • Ensure cable sizes are conservative to ensure good heat sink properties.
Note: This FAQ only applies to contactors used under continuous thermal current conditions (AC1 duty) and is complimentary to the information provided in the catalogue.

Resolution 154640
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