Carrier 50FK - Manual

Controls Operation,
and Troubleshooting
CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . 2
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Rooftop Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
VAV Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Processor Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
• P1 — SUPPLY-AIR SET POINT
• P2 — ECONOMIZER POSITION
• P3 — RESET LIMIT
• P4 — DEMAND LIMIT
• P5 — ECONOMIZER MINIMUM POSITION
• P6 — WARM-UP SET POINT
• P7 — SASP RESET TEMPERATURE
• PROCESSOR BOARD OUTPUTS
• CONFIGURATION HEADER AND DIP SWITCH
ASSEMBLY
Relay Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Display Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Thermistors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
• T1 — SUPPLY-AIR TEMPERATURE THERMISTOR
• T2 — RETURN-AIR TEMPERATURE THERMISTOR
• T3 — SATURATED CONDENSING TEMPERATURE,
CIRCUIT 1
• T4 — SATURATED CONDENSING TEMPERATURE,
CIRCUIT 2
• T10 — RESET TEMPERATURE
Compressor Operation . . . . . . . . . . . . . . . . . . . . . . . . . 7
• CONTROL RELAY (CR)
Accessory Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
• P3 — RESET LIMIT
• P5 — ECONOMIZER MINIMUM POSITION
• P6 — MORNING WARM-UP TEMPERATURE
Single-Step Demand Unit . . . . . . . . . . . . . . . . . . . . . . . 7
Demand Limit Control Module (DLCM) . . . . . . . . . . . . 7
Economizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
• ENTHALPY CONTROL
• DIFFERENTIAL ENTHALPY
Variable Frequency Drive (VFD) . . . . . . . . . . . . . . . . . 12
Temperature Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
CONTROLS INSTALLATION . . . . . . . . . . . . . . . . . . . 13-25
Control Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
• NIGHT SETBACK THERMOSTAT
• SPACE TEMPERATURE RESET ACCESSORY
(50DJ900021)
Space Temperature Reset . . . . . . . . . . . . . . . . . . . . . . 13
• INSTALLATION
• CONFIGURATION
• OPERATING SEQUENCE
Demand Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
• SINGLE-STEP DEMAND LIMIT
• TWO-STEP DEMAND LIMIT
• INSTALLATION
• CONFIGURATION
• OPERATING SEQUENCE
Control From Remote Building Management
System (BMS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
• OCCUPIED/UNOCCUPIED
Page
• NIGHT SETBACK CONTROL
• UNIT SUPPLY AIR SET POINT ADJUSTMENT
• DEMAND UNIT (1-STAGE OR 2-STAGE)
• SUPPLY DUCT PRESSURE SET POINT ADJUSTMENT
• EXTERNAL ALARM SIGNAL
• REMOTE ECONOMIZER CONTROL
Smoke Control Modes . . . . . . . . . . . . . . . . . . . . . . . . . 21
• FIRE SHUTDOWN MODE
• PRESSURIZATION MODE
• EVACUATION MODE
• SMOKE PURGE MODE
• INSTALLATION
• CONFIGURATION
• OPERATING SEQUENCE
Air Pressure Tubing . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
• INLET GUIDE VANES
• VARIABLE FREQUENCY DRIVE
• MODULATING POWER EXHAUST
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-30
Initial Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Configuration Header . . . . . . . . . . . . . . . . . . . . . . . . . 26
DIP Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Adjusting Set Points . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Potentiometers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Supply Fan Control with IGV Option . . . . . . . . . . . . . 28
Supply Fan Control with VFD Option . . . . . . . . . . . . 28
Modulating Power Exhaust
(Option or Accessory) . . . . . . . . . . . . . . . . . . . . . . . 30
START UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31-34
Quick Test Program . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
OPERATING INFORMATION . . . . . . . . . . . . . . . . . . . 34-43
Digital Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
• CODES 0 THROUGH 8, CAPACITY STEPS
• CODES 20 THROUGH 30 AND 88, OPERATIONAL
STATUS
• CODES 51 THROUGH 87, DIAGNOSTIC
INFORMATION
Operating Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . 35
• SIZE 034, 038 AND 048-088 UNITS
• SIZE 044 UNITS
• SIZE 104 UNITS
Head Pressure Control . . . . . . . . . . . . . . . . . . . . . . . . 36
Supply Fan Control with IGV . . . . . . . . . . . . . . . . . . . 38
Supply Fan Control with VFD . . . . . . . . . . . . . . . . . . . 38
Modulating Power Exhaust (Option or
Accessory Except FY,JY Units) . . . . . . . . . . . . . . . 38
Unit Staging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . 44-57
Checking Display Codes . . . . . . . . . . . . . . . . . . . . . . . 44
Complete Unit Stoppage . . . . . . . . . . . . . . . . . . . . . . . 44
Single Circuit Stoppage . . . . . . . . . . . . . . . . . . . . . . . 44
Restart Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Diagnostic Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
• CODES 51, 52, 55, 56: COMPRESSOR FAILURE
48FK,JK034-074
50FK,FY,JK,JY034-104
Variable-Air Volume Rooftop Units
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 1
Tab 1a 1b
PC 111 Catalog No. 534-716 Printed in U.S.A. Form 48/50F,J-1T Pg 1 4-99 Replaces: 48/50D,F,J-1T