Voyager and Precedent EFlex/17seer Enhanced Dehumidification sequence of operation
Feature:
Voyager and Precedent EFLEX and 17 Seer feature Enhanced de-humidification. This Feature is to help with humidity control during low load situation, by locking in compressor to fan ratio with DX cooling to provide the maximum Latent removal from the space. REMEMBER THIS ISN'T Hot gas reheat and will subcool the space. This Feature is not available on MZVAV. The reason is with enhanced dehumidification, the fan is commanded to a Constant Volume speed.
Control:
To enable this feature a wired sensor has to be put on the units LTB. 4-20ma between LTB pins 18 & 19. Humidity set point is controlled by BAS, TD5, or Local potentiometer on the RTOM R41
Sequence of operation:
Once the Space Humidity value exceeds the Dehumidification Setpoint and dehumidification is enabled the unit will transition to the Enhanced Dehumidification mode If the Following rules are true.
- Outdoor Temps are below 100° F and above 40° F.
- Space temp is < cooling set point + 3° F
- Space temp is > 1° F of the heating set point. (during unoccupied periods enhanced will follow the occupied heating set point for control)
Enhanced dehumidification will be terminated if any of the following are true:
- Space Humidity < Dehumidification Setpoint - 5% (Eflex)
- Space Humidity < Dehumidification Setpoint - 2% (17 Seer)
- Space temp > cooling setpoint + 3.5° F
- Space temp < cooling setpoint - 1.5° F (cooling only units)
- Space temp < heating setpoint + 0.5° F
- Outdoor air temp is above 100° F or below 40° F
BAS Control- A wired sensor has to be hooked to the unit at startup for Bas to pull in dehumidification control. This applies to Wifi as well. If it doesn't you will have to clear the controller and wire the sensor up then allow Bas to pull in the points again
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.