Control System

Microprocessor-based Unit Controller is factory mounted, wired and tested to ensure a protection of the Machine and efficient capacity control. The program logic provides proper Start/Stop of the Machine and also enables a communication interface with others.

• Component Test and Diagnostic Check
  
• Touch Screen Interface for Status Display, Set-point Control, and System Configuration
  
• Primary and Secondary Status Messages
  
• Individual Start/Stop Schedules for Local Mode
  
• Recall of Up to 999 Alarm and Alert Messages with Diagnostic Help
  
• Extensive Diagnostic and Service Capabilities
  
• Advanced Crystallization Protection

Safety Cutouts

• Solution Pump Motor Overload/High Temperature
  
• Refrigerant Pump Motor Overload/High Temperature
  
• Low Chilled Water Temperature Cutout
  
• Low Refrigerant Temperature Cutout
  
• Low Cooling Temperature Cutout
  
• Low Chilled Water Flow Cutout
  
• Low Cooling Water Flow Cutout (Option)
  
• Generator High Temperature Cutout
  
• Hot Water High Temperature Cutout (Low Temp. Hot Water Driven type only)
  
• High Temperature Generator High Pressure Cutout (Exhaust Gas Driven type only)
  
• High Temperature Generator Low Level Cutout (Exhaust Gas Driven type only)

Protective Limits

• Strong Solution Leaving High Temperature Generator Alarm
  
• Hot Water High Temperature Alarm (Low Temp. Hot Water Driven type only)
  
• Refrigerant Pump Overload/High Temperature Alarm
  
• Solution Pump Motor Overload/High Temperature Alarm
  
• Low Refrigerant Temperature Alarm
  
• Low Chilled Water Temperature Alarm
  
• Low Cooling Water Temperature Alarm
  
• Low Chilled Water Flow Alarm

Overrides

• Hot Water High Temperature (Low Temp. Hot Water Driven type only)
  
• Generator Solution High Temperature
  
• High Concentration

Temperature Sensor Faults

• Leaving Chilled Water Temperature
  
• Cooling Water Temperature Entering Absorber
  
• Refrigerant Condensate Temperature from Condenser
  
• Refrigerant Evaporating Temperature
  
• Strong Solution Temperature Leaving Generator
  
• Entering Hot Water Temperature (Low Temp. Hot Water Driven type only)
  
• Exhaust Gas Temperature Cutout (Exhaust Gas Driven type only)

Capacity Control

• Leaving Chilled Water Control
  
• Running Travel Limit (Control Valve Opening Limit)

Indications

• Chiller Operating Status Message
  
• Absorption Cycle State Points
  
• Dilution Cycle
  
• Power-On
  
• Alarm
  
• Safety Shutdown Message
  
• Run Hours
  
• Control Valve Position