The Fan RF or EF Vol Match for UL-864-UUKL module controls a variable speed fan and maintains a volume differential between the supply and return or exhaust ducts in an AHU application. This module accepts discharge and supply flows, a low limit temperature, PID tuning parameters, and setpoints. The module has outputs for controlling a variable speed return or exhaust fan. In addition to the volume matching capabilities, this module also has a low limit function where the differential flow setpoint is decreased when the low limit temperature is below the low limit setpoint. This module accepts commands from a FSCS. The FSCS input takes precedence over the mode input. This module also incorporates tracking the overridden value of the actual output object (AO, PAO). The module resets the PIDs to default tuning parameters if the Reset PID Tuning input is not Normal.
Important: As of Release 5.0, the Fan RF or EF Vol Match for UL-864-UUKL v50 module replaces the Fan RF or EF Vol Match for UL-864-UUKL module.