Space heater for outdoor control cabinet 2

[jacphi]

hi all,
The local specification for outdoor control cabinet states that
"The interiors of unventilated metal cabinets (exclusive of internal heat-producing sources) can reach 56°C. The components and its accessories, including cabinets and junction boxes, shall be designed accordingly"

The question here is regarding designing a space heater system with thermostat for the outdoor control cabinet. Is it required that the space heater works above ambient in order to function efficiently to remove condensation. The ambient in this case is around 45°C
regards,

 

[jraef]

No!
The space heater only needs to function to maintain the internal temperature above the dew point, 40 deg F, not C! Thats only about 5 deg. C.

 

[busbar]

 
Heaters do not “remove condensation”—they prevent it from occurring by raising surface temperatures to above dewpoint, limiting its formation on electrically insulating surfaces {in enclosures.}

Depending on reliability expected, ½-voltage, ¼-watt-density finned, nickel-alloy heaters with 250°C {TGGT} wiring and similarly rated ring terminals may be in order.

A caution in installation of heaters or adjacent field wiring is to provide adequate clearance to limit short- or long-term insulation heating and deterioration.