Carrier PC 111 - page 14

Fig. 20 — Unit Control Box Arrangement, Sizes 034-048

Contents

Main Controls Operation, and Troubleshooting CONTENTS 48FK,JK034-104 48FM078-104 50FK,FY,JK,JY034-104 50FM,FS078-104 Variable-Air Volume Rooftop Units CONTENTS (cont) SAFETY CONSIDERATIONS GENERAL Rooftop Information VAV Control System Processor Board Fig. 1 Processor Board Page Relay Board Display Board Thermistors Table 3 Output Pin and Terminal Assignments Fig. 5 Relay Board Compressor Operation Accessory Board Single-Step Demand Limit Demand Limit Control Module (DLCM) Page Page Economizer Page Supply Fan Variable Frequency Drive (VFD) High Capacity Modulating Power Exhaust Variable Frequency Drive (48FM and 50FM,FS Units Only) Temperature Reset CONTROLS INSTALLATION Control Wiring Space Temperature Reset Page Page Page Page Demand Limit Control From Remote Building Management System (BMS) [(P3 SASP) X(0.6 F) X (TR R@13.3) ] Smoke Control Modes Page Air Pressure Tubing 034-048 UNITS Fig. 32 Smoke Control Wiring 054-104 UNITS 48FK, JK AND 50FK, JK034-104 UNITS 48FM, AND 50FM, FS034-104 UNITS START-UP Initial Check Configuration Header DIP Switches Adjusting Set Points Potentiometers Supply Fan Control with IGV Option Supply Fan Control with VFD Option STOP RESET RUN READ WRITE Modulating Power Exhaust (Option or Acces- sory) (48FK,JK and 50FK,JK Units) The Mod- High Capacity Power Exhaust (48FM and 50FM,FS Units) The power exhaust VFD will modu- START UNIT Quick Test Program Turn on power to unit. Table 16 Quick Test, Unit Configuration and Switch Check Table 17 Quick Test, Thermistor and Potentiometer Check Table 18 Quick Test, Output Relay Check OPERATING INFORMATION Digital Display The VAV control system uses a 2-digit Operating Sequence The sequence presented be- Head Pressure Control All units have as standard a Page Supply Fan Control with IGV In most VAV units, Supply Fan Control with VFD When equipped Modulating Power Exhaust (48FK,JK and 50FK,JK Units Option or Accessory) The pow- High Capacity Modulating Power Exhaust (48FM and 50 FM,FS Units) The high-capacity Unit Staging Compressor loading and unloading se- Page Page Page Table 20 Compressor Loading and Unloading Sequences Fig. 48 Modulating Power Exhaust Return End Sheet Metal Skin Detail; 48FM and 50FM,FS Units Table 20 Compressor Loading and Unloading Sequences (cont) TROUBLESHOOTING Checking Display Codes To view the digital dis- Complete Unit Stoppage If the unit is off, there are Single Circuit Stoppage If a single circuit stops, Restart Procedure Before attempting to restart the Diagnostic Codes Diagnostic codes are warnings of Page Page Thermistor Troubleshooting The VAV con trol Electronic Controls Checkout The following will Page Page Page Enthalpy Sensor Checkout To test operation of Economizer Motor All control of the motor (i.e., Supply Fan Variable Frequency Drive Page Table 30 Carrier Default Program Parameter Values (Supply Fan VFD) Power Exhaust Variable Frequency Drive (48FM and 50FM,FS) Fig. 56 Variable Frequency Drive Terminal Block Unit Wiring A typical wiring schematic is shown in LEGEND AND NOTES FOR FIG. 57 Page Page Page SERVICE TRAINING START-UP CHECKLIST I. PRE-START-UP: II. PRELIMINARY CHECKLIST ITEMS: III. START-UP IV. NOTES