Emerson Exchange 365

-4 F to 176 F (or -20C and 80C)

In reply to ekilkenny:

To clarify, these are the limits applied to the CIOC temperature reading, which is the internal temperature on the card.

We've done some testing here in Calgary and have data from three customer CIOC's. These have a wide range of CHARMS installed but the result is pretty consistent. The Ambient temperature around the CIOC runs between 19.6 and 21 degrees cooler than the internal diagnostic temperature. So the alert an -20 coincides with an ambient of -40 Deg C, and the alert at 80 occurs around 60 Deg C ambient.

On my CHARM panel installed outside, over the last 3 years, the offset has been very consistent at 20.5 deg C even at -30 Deg Air temperature and +35 Deg C.

I strongly recommend not to install a temperature sensor in these outdoor panels because the internal temperature is more than adequate to indicate ambient are in the cabinet. But also, since there we don't install any active cooling, there isn't really anything to monitor the temperature for. In regular cabinets, with fans, we would monitor temperature as an indication that fans failed and internal air temperature was above the expected controlled value. In a remote panel, temperature swings with the ambient temperature, and if the sun hits the panel, this can add 10 to 12 Deg C via radiant heat. If its a sunny day, and warm, hitting 60 deg C might be normal. If its only 10 degrees C at night, and the alarm goes off, something is wrong. I'm thinking the built in Hardware alert is adequate for high temp.

If the panel has a heater for low temperature extremes, you might want to set an alert if the temperature goes below -20 as the heater may not be working. if there's no heater, no need to set a low temperature alert.

We recommend displaying an inferred ambient temperature to the Operator by subtracting the offset. The temperature profile from the internal temp follows ambient with a bit of delay, but is very repeatable.

Andre Dicaire