Temperature protection in nema-rated enclosures – Rockwell Automation 2706-P42R_P42C_P43R_P43C_P44R_P44C_P72CNx_P74CNx InView Marquee Message Display User Manual
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Publication 2706-IN006E-EN-P
18 InView Marquee Message Display
Temperature Protection in
NEMA-Rated Enclosures
InView P42, P43, P44, P72, and P74 signs have automatic temperature
controls that help to protect the sign from damage when the internal
temperature of the sign is too hot to continue normal operation.
•
If the internal temperature of the sign reaches a pre-determined
“dimming point”, the LED output from the sign is forced into a
50 percent reduced power mode, effectively dimming the
brightness of LED output by about 50 percent.
•
If the internal temperature of the sign continues to increase,
another sensing circuit will execute an automatic shut down to
protect the sign from damage. The LED output from the sign is
turned off.
•
The dimming and shutdown points are listed in the table below.
Once the temperature drops below the auto-shutdown
threshold, the LED output is turned on at the dimming level.
Once the temperature drops below the dimming threshold,
auto-dimming is disabled and the LED brightness is back to 100
percent.
Table B
Model
Enclosure
Dimming Point
Auto-Shutdown On
2706-P42, 2706-P44
NEMA 12
55°C (131°F)
70°C (158°F)
2706-P43
NEMA 12
55°C (131°F)
70°C (158°F)
2706-P72, 2706-P74
NEMA 4, NEMA 4x
55°C (131°F)
70°C (158°F)
TIP
Take into account the effects of ambient temperature
when evaluating mounting locations for the sign.
You should always maintain recommended clearance
distances around the sign and avoid poorly
ventilated mounting locations that could be subject
to radiation, convection, conduction or other thermal
transfer effects.