Emerson iCOM user manual Supply Limit-Optional, High and Low, Temperature and Humidity Events

Operation

3.7.3Supply Limit—Optional

Chilled water units may be ordered with an additional sensor for monitoring the supply air tempera- ture. This sensor maintains the minimum air temperature under a raised floor to help prevent con- densation from forming. In order to avoid supply temperatures that are too low, the Supply Limit can influence the opening of three-point or analog actuators or the output of analog values.

The control compares the deviation from the return air setpoint and the supply limit setpoint, and cal- culates the output to the actuator from the smaller deviation.

NOTE

The Supply Limit is calculated on each unit, independent of the other sensor readings on the network.

3.7.4High and Low, Temperature and Humidity Events

High- and low-temperature and humidity alarms can be set for both the internal and optional exter- nal sensors. If a sensor reading exceeds a preset threshold, a warning will appear. These warnings are ignored after unit startup for a minimum of 1 minute. To increase the delay to warn, see 3.7.6 - Event Types and Properties. The threshold settings are located in both the User and Service menus under Set Alarms.

To apply threshold limits on the internal cooling unit sensors, the Return Sensor Alarms must be enabled. The high and low temperature and humidity internal sensor thresholds can then be set. To apply threshold limits on the optional external sensors, the Sensor A alarms must be enabled. The high and low temperature and humidity external sensor thresholds can then be set. If no external sensors are connected to the unit, it is recommended that the Sensor A Alarms be disabled.

NOTE

The event messages will automatically reset if the temperature/humidity stays 1.8°F (1°C)/ 2% RH below or above the threshold for one minute.

32