Carrier FK4CNF - User Manual

Residential Fan Coil Units
Service Manual
TABLE OF CONTENTS
Page
SAFETY CONSIDERATIONS...................................................2
INTRODUCTION........................................................................2
UNIT IDENTIFICATION...........................................................2
PRODUCT OFFERING..............................................................4
FAN MOTOR SPEED TAPS .....................................................4
FA4A, FB4A, FC4B, FF1D, FH4A, AND FX4A
CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING
— CES013003-00 and -01 PCB...............................................2-7
• Printed Circuit Board Component Layout and Description.......2
• Unit Functions ............................................................................2
• Troubleshooting PCB..................................................................4
CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING
— HK61GA001 and HK61GA003 PCB .........................6-19
• Printed Circuit Board Component Layout and Description.......6
• PCB Component Functions.........................................................7
• Troubleshooting PCB................................................................11
ELECTRIC HEATER FUNCTION
AND TROUBLESHOOTING..............................................18
• Description of Electric Heater Components.............................19
• Troubleshooting KFA, KFB, KFC, and KFD Series
Electric Heaters.......................................................................20
FAN COIL DESCRIPTION AND
TROUBLESHOOTING — FK4B .................................20-27
• Integrated Controls and Motor (ICM2)....................................20
• PCB Layout and Description....................................................20
• Sequence of Operation..............................................................21
• Easy Select Configuration Taps................................................22
• Troubleshooting PCB................................................................25
• Troubleshooting ICM2..............................................................25
• Condensed Version of Troubleshooting FK4B Motor
and Controls ...............................................................................27
• Accessories ................................................................................27
FAN COIL DESCRIPTION AND
TROUBLESHOOTING — FK4C, FV4A, 40FKA.........28-35
• Integrated Controls and Motor (ICM2)..................................28
• PCB Layout and Description..................................................29
• Sequence of Operation............................................................29
• Easy Select Configuration Taps..............................................32
• Troubleshooting PCB..............................................................33
• Troubleshooting ICM2............................................................33
• Condensed Version of Troubleshooting
FK4C, FV4A, 40FKA Motor and Controls.........................33
• Accessories ..............................................................................35
THERMOSTATIC EXPANSION VALVES (TXV)............36
• Problems Affecting TXV........................................................36
PISTON BODY CLEANING OR REPLACEMENT..........36
LIQUID TUBE STRAINER ...................................................37
FA, FB, FC, FK COIL/CONDENSATE PAN
REMOVAL AND REPLACEMENT..........................37-38
• A-Coil Units ............................................................................37
• Slope Coil Units......................................................................37
FX, FV, 40FKA COIL/CONDENSATE PAN REMOVAL
AND REPLACEMENT ................................................38-40
CARE AND MAINTENANCE...............................................39
• Filter Assembly .......................................................................39
• Cooling Coil, Drain Pan, and Condensate Drain...................39
• Blower Motor and Wheel .......................................................40
FF1A/FF1B/FF1C SERVICE AND
TROUBLESHOOTING................................................40-42
• Fan Motor................................................................................40
• Electric Heater Service............................................................40
• Cleaning or Replacing Refrigerant Flow-Control Device .....42
• Liquid Tube Strainer ...............................................................42
• Sequence of Operation............................................................42
• Care and Maintenance.............................................................42
FD3A SERVICE AND TROUBLESHOOTING...............43-45
• Fan Motor..................................................................................43
• Electric Heater Service..............................................................43
• Cleaning or Replacing Refrigerant Flow-Control Device .......43
• Liquid Tube Strainer .................................................................45
• Care and Maintenance...............................................................45
FG3A SERVICE AND TROUBLESHOOTING....................46
• Service .......................................................................................46
• Maintenance...............................................................................46
FA4A, FB4A, FC4B, FX4A SMART HEAT CIRCUIT
BOARD FUNCTION AND TROUBLESHOOTING..46-50
• PCB Component Layout, Description, and Function...............46
• Unit Functions ...........................................................................47
• Smart Heat Operation................................................................48
• Electrical Operating Sequences and Troubleshooting..............48
PURON® (R-410A) QUICK REFERENCE GUIDE.............51
Fig. 1—Typical Fan Coil
A98023
Visit www.carrier.com
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
Tab 3d 2e
PC 101 Catalog No. 03FA-4A3 Printed in U.S.A. Form F-5SM Pg 1 6-99 Replaces: F-4SM

Carrier FK4CNF Specifications

General

Cooling Capacity	12000 BTU/h
Energy Efficiency Ratio (EER)	11.0
Refrigerant	R410A
BTU	12000
Type	Mini-Split
Power Supply	208-230V, 60Hz, 1Ph
Outdoor Unit Dimensions (H x W x D)	21.3 x 31.5 inches
Heating Capacity	12000 BTU/h

Summary

Safety Considerations

FA4 A, FB4 A, FC4 B, FF1 D, FH4 A, AND FX4 A CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING

CES0130003-00 and -01 PCB

Description of the CES0130003-00 and -01 PCB functional operation and components.

Troubleshooting the Printed-Circuit Board

IF PCB HAS HIGH VOLTAGE APPLIED TO IT

Steps to diagnose issues when high voltage is applied to the PCB.

IF TRANSFORMER FUSE KEEPS BLOWING

Troubleshooting steps for a constantly blowing low-voltage transformer fuse.

IF ELECTRIC HEAT STAGES WILL NOT TURN ON BUT FAN WILL TURN ON

Diagnosing why electric heat stages fail to activate while the fan operates.

CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING HK61 GA001 and HK61 GA003 Circuit Boards

TRANSFORMER

ELECTRIC HEAT

Explanation of electric heat operation and signals to the PCB.

AUX1 and AUX2 for 2-Speed Fan Relay Kit

IF THE FAN WILL NOT TURN ON FROM THE THERMOSTAT

If there is no high voltage to the PCB

Troubleshooting steps for no high voltage supply to the PCB.

FK4 C, FV4 A, and 40 FKA DE-HUMIDIFY MODE

Step 9-Integrated Controls and Motor (ICM2)

Description of the Integrated Controls and Motor (ICM2) for FK4C/FV4A/40FKA.

ELECTRIC HEATER FUNCTION AND TROUBLESHOOTING

Troubleshooting KFA, KFB, KFC, and KFD Series Electric Heaters

Troubleshooting specific electric heater models KFA, KFB, KFC, KFD.

FAN COIL DESCRIPTION AND TROUBLESHOOTING FK4 B

Step 1-Integrated Controls and Motor (ICM2)

Description of the Integrated Controls and Motor (ICM2) system.

CFM SELECT CONFIGURATION TAPS

Troubleshooting the PCB

IF FAN WILL NOT TURN ON FROM THERMOSTAT

Troubleshooting steps for fan not turning on from thermostat.

IF MOTOR DOES NOT RUN

Steps to troubleshoot motor not running issues.

IF MOTOR DOES NOT STOP RUNNING

Step 7-Condensed Version of Troubleshooting FK4 B Motor and Controls

Condensed troubleshooting summary for FK4B motor and controls.

PISTON BODY CLEANING OR REPLACEMENT

FA, FB, FC, FK COIL;CONDENSATE PAN REMOVAL AND REPLACEMENT

FX4 A AND FV4 A COIL;CONDENSATE PAN REMOVAL AND REPLACEMENT (PURON REFRIGERANT)

Step 1-A-Coil Units

CARE AND MAINTENANCE

Inspect and clean or replace air filter each month or as required.

Inspect cooling coil, drain pan, and condensate drain each cooling season for cleanliness.

Inspect blower motor and wheel for cleanliness each heating and cooling season.

FF1 A;FF1 B;FF1 C SERVICE AND TROUBLESHOOTING

Step 3-Cleaning or Replacing Refrigerant Flow-Control Device

FD3 A SERVICE AND TROUBLESHOOTING

Step 1-Fan Motor

Step 2-Electric Heater Service

Service procedures for electric heaters in FD3A units.

Step 5-Care and Maintenance

BLOWER MOTOR AND WHEEL

FG3 A SERVICE AND TROUBLESHOOTING

MOTOR

BLOWER

FA4 A, FB4 A, FC4 B, AND FX4 A SMART HEAT CIRCUIT BOARD FUNCTION AND TROUBLESHOOTING

Step 3-Smart Heat Operation

TROUBLESHOOTING PRINTED-CIRCUIT BOARD (DIAGNOSTIC LED)

Using the diagnostic LED for PCB troubleshooting.

Step 4-Electrical Operating Sequences and Troubleshooting

READY-TO-START

CONTINUOUS FAN

PURON (R-410 A) QUICK REFERENCE GUIDE FOR INSTALLERS AND TECHNICIANS