Orion Car Audio OE331-21 manual Sample #2

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Sample #2

The user would like to use the GPC Plus as a Lead/Lag Air Handling Unit Controller. The installation is located in a critical area that does not tolerate the space temperature going out of control. The method chosen was to install a backup AHU that would take over in case of failure on the Lead AHU. Also, since the units are identical, the owner wanted to equalize the run-times to lengthen the time between routine maintenance service calls. The easiest method for handling this was to use two, standard, off the shelf AHU controllers and a GPC Plus controller that would enable the appropriate AHU based on changeover and failure mode conditions. The GPC Plus would use contact closures to the Forced Occupied inputs of the AHU controllers to activate and de-activate the units. A failure mode would be indicated by the failure of the Supply Air Temperature to drop below or stay below a 60°F setpoint. Any temperature excursions above 60°F for more than one minute would indicate a failure had occurred and that the Lag AHU should be activated and an Alarm generated to let building maintenance know there was a problem.

Analog Input #1 Configured as Thermister Type III Sensor to measure Supply Air

As you can see, this input does not use a schedule for Night Setbacks since the unit will run 24 hours a day. It does however, monitor the Supply Air Temperature for values that are out of limits for more than a half hour and generates an alarm condition. This is a fall

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Contents GPC Plus Controller Page OE331-21-GPC OE331-21-GPCPLUS +VDC AIN1 Page Main Status Screen General Purpose ControllerDescription Analog Inputs Relays Analog Outputs Week Schedules & Holidays Analog Input Configurations Page Page RH% Wall Sensor Slide Offset Push-Button Override Optimal Start TemperaturesAnalog Input #6 Control Methods Relay Output ConfigurationEnabling Relay Control/Reset SourcesDelay & Run Times Reset Source LimitsAND/OR Conditional Tests Controlling Setpoint DeadbandControlling Schedule Lead/Lag Control Run Time AlarmRelay Output Type Global Binary ChannelVentilation Control Possible Control Modes Analog Output ConfigurationPID Control Possible Control SourcesFloating Point Control Alternate Override Proportional Reset SignalEconomizer Control Lead/Lag Pump VFD Control Sample #1 Sample ConfigurationsPage Page Relay Output #2 Programming Used for Boiler #1 Relay Output #3 Programming Used for Boiler #2 Relay Output #4 Programming Used for Boiler #3 Relay Output #5 Programming Used for Boiler #4 Operation Page Sample #2 Page Page Page Main Status Screen Failure Mode Page