TEC Zoning Control System for Stand-Alone and BACnet® MS/TP ...

Table 2: TEC2647Z-2 and TEC2647Z-2+PIR Zone Controller InstallerConfiguration Menu (Part 7 of 7)ParameterAppearingon DisplayPICL Wei 7Description and DefaultSets the weight of the PI coolingdemand of a zone, used in thePI cooling calculation of the zonecontroller.Default: 100%Selection Options(0%): PI Cooling Weight of 0%(25%): PI Cooling Weight of 25%(50%): PI Cooling Weight of 50%(75%): PI Cooling Weight of 75%(100%): PI Cooling Weight of 100%Note: A zone that includes a special application (such as a serverroom, mechanical room, or cafeteria) may affect the averagecooling demand at the rooftop controller level, resulting indiscomfort in other zones. Setting the PI cooling weight to0% eliminates this problem.1. Zone MAC is the unique device address of the zone controller (from 004 to 127) on the MS/TP network.2. RTC MAC is the unique device address of the rooftop controller (from 004 to 127) on the MS/TP network.3. The standby setpoints are used in the standby mode. The PIR Func parameter must be set to on, or the BI1 parametermust be set to either MotionNO or MotionNC to enable the standby mode.4. The settings for this parameter are valid only if the analog reheat sequences are enabled.5. The settings for this parameter can only be enabled if an outside air temperature sensor is connected and ready foroperation.6. The MaxHTPos value should never be lower than the Min Pos value; likewise, the MaxHTPos value should never behigher than the Max Pos value.7. The setting for this parameter does not change the PI demand used locally at the zone controller to maintain the setpoint;instead, it only adjusts the PI demand transferred to the rooftop controller for its highest/average demand calculations.TEC2647Z-2 and TEC2647Z-2+PIR Zone Controller Operation andStrategyThe zone controller is designed to control a proportional 0 to 10 VDC modulatingdamper actuator, unlike low-end commercial and residential zoning thermostatsthat are designed to control two-position (open/closed) damper actuators.Proportional modulating control enables performance and control sequences thatare much closer to what is normally found in Direct Digital Control (DDC),application-specific control devices. Proper operation of the zone controllersrequires proper communication between the rooftop controller and its associatedzone controllers.The data exchange from the zone controllers to the associated rooftop controllerincludes:• current Proportional plus Integral (PI) heating demand, whereby the outputvalue is based on the PI heating weight configuration• current PI cooling demand, whereby the output value is based on the PI coolingweight configurationThe data exchange from the rooftop controller to the associated zone controllersincludes:• current central system occupancy• current system mode active (hot or cold air being delivered)• outside air temperatureTEC Zoning Control System for Stand-Alone and BACnet® MS/TP Networked ApplicationsTechnical Bulletin21