Issue:
What is the operating temperature range for the NQ, NF, I-line, and QMB panelboards

Product Line:
Panelboards

Environment:
NQ, NF, I-line, QMB

Cause:
Operating temperature ranges for panelboards

Resolution:
Square D panelboards are designed to meet the requirements of UL 67 which designates that heat rise of internal components must not exceed the test limits when measured at ambient temperatures of  +10C to +40C (50F - 104F) when carrying the rated current of the panel.
When panelboards are operated outside of these temperature ranges, consideration must be given to the operation of the circuit breakers being used.  SquareD provides derating information for circuit breakers here.

SquareD offers options for panelboards to include heating strips with thermostatic control to maintain temperature in colder environments, which can also be helpful in minimizing condensation.
When used in temperatures above 40C, reference the derating document above and consider the use of temperature-controlled space.
Additionally, if WP enclosures are in use and placed in direct sunlight, the solar effect should be considered and the proper breaker derating applied, as well as consideration of using temperature-controlled space for the panelboard.

Released for: Schneider Electric Canada