LCD display below freezing


Thread Starter

Toni Kaesbeck

Are there any display units for temperatures below 32Fahrenheit / 0Celsius rated for Class1, Div2? I understand that there is a physical limitation for that, but maybe there is an alternative. I am looking for a text or graphical display to be mounted into an NEMA 4X
enclosure door for outdoor use, best with a MODBUS interface.

Toni Kaesbeck
Toni, it isn't the display unit, but the entire instrument that is rated. It is certainly possible to put an LED or plasma display in a transmitter, rate it to -40 degrees, and have FM/CSA/Cenelec rate it for Class I Div 2. Class I, Div. 2 is an exceptionally easy rating to get, and most industrial transmitters actually either qualify for it, or can be made to qualify for it very easily. Alternatively, you might consider shipping the transmitter with an "O'Brien bag" as standard equipment, so that its own internal heat
doesn't dissipate and will maintain it above the point where the LCD gets so slow that it doesn't display any longer.


Walt Boyes

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Keep in mind what LCD means - "Liquid Crystal Display". All LCD I've used (like digital clocks in my car) tend to cloud up/darken when the Minnesota weather was below 0. i assume the liquid changes its characteristics in the cold.

I suspect you'll need to use plasma or LED technology, not LCD if you want to have a true cold-weather display. I'd try to broaden your search of the small display companies to the non-LCD forms.

- Lynn

Ralph G. McDonald

You might try PCS Computer, an Advantech subsidiary. They have an outdoor panel PC that is rated for an operating enviroment of -20 DegC to +60 DegC, and NEMA 4X. Check at Please let me know how it works if you use it. It is a little pricey for most of our clients.

Ralph G. McDonald, P.E.
Spicer Group

Toni Kaesbeck

Thanks for your answer. Maybe I wasn't specific enough:
I am looking for a "front panel display", which shall go into an enclosure door with the enclosure mounted outside a building. Inside the enclosure is a RTU or PLC (which is rated Class I Div 2). The enclosure is NEMA 4X and I want to connect via a RS232 protocol to the front panel. Main purpose:
Display measured values from several distributed transmitters in one location out in the filed.

I have looked around quiet a bit (maybe at the wrong places), but all displays were rated with a low of 0C.


Steve Myres, PE

I assume the interior of the cabinet is temperature controlled and that's why you are concerned only with the display unit and not the PLC or RTU. If this is the case, and if you don't need touchscreen input capability, or can substitute a mouse, try recessing the display unit an inch or two on a secondary panel behind a glass window. You could then install a fan and blow an air curtain of (relatively) warm enclosure air down in the space between the window and the display. This might help prevent condensation on the inside of the window as well.

Steve Myres, PE
[email protected]