The Light Commercial Unit (LCU) must be capable of dehumidification. Under normal operating conditions for the LCU to go into Dehumidification mode, the Cooling Capacity must be less than 50% and Space Humidity active must be greater than the Dehumidification Setpoint active.
- Standalone LCU with Comparitive Enthalpy Economizer strategy.
Reliatel LCU’s with Comparitive Enthalpy Economizer control strategy, the RAH sensor value that is being used for the Economizer Comparitive Enthalpy control strategy, will be referenced as Space Humidity Active by default. This RAH sensor value will not be used for dehumidification control, due to already being utilized for the Economizer Control strategy. For Dehumidification control, the LCU will require a hardwired humidity sensor connected to LTB3, 18 (RH+) and 19 (RH-) to allow the LCU to reference the hardwired humidity sensor as Space Humidity active. Use TD5 / Reports / Sensor Reports, to verify if the RAH humidity sensor is reporting as Space Humidity active, it is recommended to disconnect the RAH sensor from the RTEM and verify if the value reports --- (null value) or a valid value from the hardwired humidity sensor connected to LTB3, 18-19 (polarity sensitive).
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.