Last edit: 12/07/2023
Regarding the ambient temperature higher than 40°C, that was allowed also in the secondo edition, but no criteria were given. Remember that since 2022, also UL 508A allows an Industrial control panel to be installed in an ambient temperature higher than 40°C.
In the third edition of C22.2 N° 286 good guidance is given: here an abstract
[C22.2 N°286: 2023] 4.12.9 Where a control panel is intended to be installed in an environment where the external ambient temperature may at times be greater than 40°C, one or more of the following shall apply:
- Means shall be provided to control the internal ambient of the panel, such as ventilation, forced, cooling means, etc.
- Components employed in panel shall be suitably rated for the elevated ambient, or otherwise ambient compensated, particularly with respect to thermally dependent components such as circuit breakers, magnetics, etc.
- Compliance with temperature limits and proper intended operation shall be demonstrated via applicable methods such as the temperature test in Clause 7.2.