Emerson Exchange 365

Hi Greg,

This parameter is not exposed in the CSLS, there's no way to get this info.

Rgs,

In reply to Tadeu Batista:

Why do you need to measure the temperature in the panel?

I think sometimes we do things because we've lost sight of the original reason we monitored temperature in panels. For a long time, control system panels were monitored for temperature because they had active cooling, such as fans and HVAC systems that maintained a desired operating temperature. If the fans failed, or if the HVAC failed, the cabinets could get too warm. Some field panels may have active cooling such as vortex coolers, and again, failure of the cooling system requires detection so that it can be repaired and avoid premature failure of the components inside due to prolonged operation at elevated temperature.

With the CSLS field enclosures, there is no active cooling. The internal temperature of the enclosure will vary with the ambient air and possible radiant energy if exposed to sunlight. There is no cooling system that could fail resulting unobserved elevated temperature.

Monitoring the ambient temperature where these enclosures are located can give you the information you need about their operating temperature.

Assuming you still require temperature measurement inside the CSLS enclosure, there are a couple of other options:
- use a Thermal Switch wired into the fault relay circuit to a DI. If this exists, then you don't add an additional CHARM and the device is relatively inexpensive.
- if you have installed a Thermocouple signal, its cold junction compensation value will be indicative of the ambient temperature in the enclosure.

You could also consider a temporary installation of the RTD solution in that once the overall temperature profile of the installation is understood, and that you are confident there are no adverse operating conditions, the RTD channel could be repurposed in the future if the IO is needed.

I've been monitoring a CIOC panel for the last 7 years installed outside, equipped with an Outside Ambient RTD sensor, and internal cabinet ambient air RTD sensor and the CIOC onboard temperature sensor. The internal RTD and the Onboard CIOC temperature readings are very repeatable and consistently offset by about 20deg C. This is expected as the CIOC temperature is monitoring the processor temperature. The internal temperature will float about 6 degrees above the outside air at night. During the day, direct sunlight will add up to 10 deg C to the internal temperature. We see max temperatures of about 40 to 45 Deg C from time to time, resulting in a max internal temp of about 60 deg, which drops back to 50 when the sun moves past the building. For most of those hot days, the panel internal temperature is below 50 degC, and for 90% of the year remains below 35 deg C.

My point is that I know what the internal temperature is by reading the outside temperature and whether it is sunny. If the enclosure were shaded, then one variable would tell me the internal temperature of all installed panels.

If you have reason to install temperature monitoring, then the RTD is the best solution. My point is not to dissuade you from installing the RTD. I just think that without a clear reason for doing so, we may be consuming IO points that we could use for other purposes.

Andre Dicaire