Controls Interface)
Generic Building Automation System Module (GBAS) — Two Generic Building Automation System Modules (GBAS) are available as an option to provide broad control capabilities for building automation systems, other than theTrane’sTracer system.
The
The 4 analog inputs can accept a
1.Leaving Solution Set point
2.Ice BuildTerminate Set point
3.Hot Start Load Limit Set point
4.Maximum Capacity Level Set point
The 5 binary outputs can be assigned:
1.Active Unit Diagnostics
2.Compressor running status
3.Maximum Capacity (all compressors running)
4,5. Open - Diagnostics can be grouped or individually assigned by the user and may be placed in these outputs.
The
The 4 analog inputs can accept a
1.Leaving Solution Set point
2.Ice BuildTerminate Set point
3.Hot Start Load Limit Set point
4.Maximum Capacity Level Set point
The 4 analog outputs can be assigned to:
1.Leaving SolutionTemperature
2.Entering SolutionTemperature
3.Saturated CondenserTemp. Ckt 1, 2
4.EvaporatorTemp. Ckt 1, 2
5.Liquid Line Pressure Ckt1, 2
6.Suction Pressure Ckt 1, 2
7.Actual Capacity Level
8.Outdoor AirTemperature
One binary output can be assigned to:
1.Active Unit Diagnostics
2.Compressors Running Status
3.Max Capacity
Hot Gas Bypass (HGBP) — The HGBP control allows unit operation below the minimum step of unloading. Hot gas bypass is initiated when the last capacity step is running and the capacity control algorithm generates a subtract command. HGBP remains energized until the load increases, the chiller freeze protection function is activated, a user defined run time has expired, the low pressure control is open, or the unit goes into ice building mode.
Alarm and Max Capacity Relay — These features are user selectable and are mutually exclusive of each other. If the alarm relay output is selected, it will provide a way to trigger a field supplied alarm whenever the UCM detects a fault requiring manual reset. The customer can assign which fault modes will trigger the alarm relay. The alarm will
Ice Building Control — A contact closure on the UCM allows either a field installed device or an ICS system to initiate the unit to operate in the ice building mode. In this mode normal chiller temperature control is bypassed and the unit runs fully loaded until ice building is complete. There are two optional ice building modes that can be selected through the HI. Ice building is terminated when the customer provide contacts are opened, Ice Building Stop is initiated from theTracer, or the entering solution temperature reaches or drops below the ice building terminate set point.
Option 1 - One time Ice building mode allows the unit to run fully loaded until the entering solution temperature falls to the active ice building terminate set point (IBTS)When the entering solution temperature reaches the terminate set point, the unit will go through pumpdown if enabled and remain in Ice Complete standby mode until the ice build mode is terminated.
Option 2 - Continuous ice build mode allows the unit to run fully loaded until the entering solution temperature falls to the active ice building terminate set point (IBTS). When the entering solution temperature reaches the terminate set point, the unit will go through pumpdown if enabled, and remain in Ice build delay. The unit will remain in ice build standby until the ice build timer expires. The unit will then start the pump and wait for the loop stabilization timer to expire. The unit will run fully loaded until the entering solution temperature falls below the ice build termination set point. The unit will continue cycling through these ice building states until the Ice build mode is terminated or changed to option 1.
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