PURON FA4, FB4, FC4, FD3, FE4 Service Manual

...

SERVICE MANUAL

RESIDENTIAL FAN COIL UNITS

FA4, FB4, FC4, FD3, FE4, FF1, FG3, FH4, FK4,

FV4, FX4, 40FK

TABLE OF CONTENTS

Page

SAFETY CONSIDERATIONS.....................................................................................................................................................................................2

INTRODUCTION..........................................................................................................................................................................................................2

UNIT IDENTIFICATION.............................................................................................................................................................................................2

FAN COIL DESCRIPTION & TROUBLESHOOTING.....................................................................................................................................2 - 25

FK4B.................................................................................................................................................................................................................2 - 11

FV4A/FV4B/FK4C/FK4D/40FK ...................................................................................................................................................................11 - 20

FE4A...............................................................................................................................................................................................................20 - 25

CARE & MAINTENANCE................................................................................................................................................................................25 - 28

FF1A/FF1V/FF1C SERVICE & TROUBLESHOOTING.................................................................................................................................28 - 32

FD3A SERVICE & TROUBLESHOOTING.....................................................................................................................................................32 - 35

FG3A SERVICE & TROUBLESHOOTING.....................................................................................................................................................35 - 36

CIRCUIT BOARD FUNCTION & TROUBLESHOOTING............................................................................................................................36 - 56

FA4, FB4, FC4, FX4 Smart Heat Circuit Board (PCB)...............................................................................................................................36 - 42

FA4, FB4, FC4, FF1, FH4, FX4, CES013003-00 and 01 (HK61EA002) PCB..........................................................................................42 - 45

HK61GA001 and 003 PCB............................................................................................................................................................................45 - 56

ELECTRIC HEATER FUNCTION AND TROUBLESHOOTING..................................................................................................................56 - 58

THERMOSTATIC EXPANSION VALVES (TXV)..........................................................................................................................................58 - 59

COIL AND CONDENSATE PAN REMOVAL & REPLACEMENT.............................................................................................................59 - 63

FOR FV/FA/FB/FC/FK FAN COILS ..........................................................................................................................................................59 - 61

FOR FX4 AND FV4 FAN COILS................................................................................................................................................................61 - 63

PURON® QUICK REFERENCE GUIDE.................................................................................................................................................................64

Fig. 1—Typical Fan Coil

Form: F-6SM Cancels: F-5SM / SM03-5 Printed in U.S.A. 02-05 Catalog No. 03FA-4A6

A98023

This symbol → indicates a change since the last issue.

SAFETY CONSIDERATIONS

Improper installation, adjustment, alteration, service, maintenance, oruse can cause explosion, fire, electrical shock, or other conditions whichmay cause personal injury or property damage. Consult a qualified installer, service agency, or your distributor or branch for information or assistance. The qualified installer or agency must use factory-authorized kits or accessories when modifying this product. Refer to the individual installation instructions packaged with the kits or accessories for detailed information.

Follow all safety codes. Wear safety glasses and work gloves. Use quenching cloth for brazing operations. Have fire extinguisher available. Read these instructions thoroughly and follow all warnings or cautions attached to the unit. Consult local building codes and National Electrical Code (NEC) for special installation requirements.

It is important to recognize safety information. This is the safety-alert symbol

. When you see this symbol on the unit or in instructions and

manuals, be alert to the potential for personal injury. Understand the signal words DANGER, WARNING, and CAUTION. These words are used with the safety-alert symbol. DANGER identifies the

most serious hazards which will result in severe personal injury or death. WARNING signifies hazards which could result in personal injury or death. CAUTION is used to identify unsafe practices which would result in minor personal injury or product and property damage.

WARNING: UNIT OPERATION AND SAFETY HAZARD

Failure to follow this caution could result in personal injury or possible equipment damage. Puron (R-410A) systems operate at higher pressures than R-22 systems. Do not use R-22 service equipment or components on R-410A equipment. Ensure service equipment is rated for R-410A.

INTRODUCTION

The "F" series fan coil units are designed for flexibility in a variety of applications, meeting upflow, horizontal, or downflow requirements. Units are available in 1-1/2 through 5 ton nominal cooling capacities. Factory-authorized, field-installed electric heater packages are available in 3 through 30 kilowatts.

WARNING: ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury or possible equipment damage. Before installing orservicing fan coil,always turn off all power to unit. There may be morethan 1 disconnectswitch. Turn offaccessory heater power if applicable.

UNIT IDENTIFICATION

The 16 position numbering chart allows identification of all available fan coil units. (See Fig. 2.)

FAN COIL DESCRIPTION

AND TROUBLESHOOTING

FK4B

The FK4B has an integrated control and motor (ECM/ECM/ICM) and special circuit board. Setting up desired airflow on the FK4B is obtained by the selections made on Easy Select™ circuit board. The motor delivers requested airflow

as defined by signals received from Easy Select Board and its internal programming. The major differenceis that the FK4Bmotor reacts to changes in system static pressures to maintain constant airflow.

Unlike conventional fan coils where static pressure affects airflow, the FK4B is a constant airflow unit. The blower delivers requested airflow up to about 0.7 in. of static pressure. The motor is pre-programmed and contains airflows for all modes of operation. Blower characteristics (airflow, torque, and speed-vs-static pressure) are known from laboratory testing. If any 3 characteristics are known, the fourth is defined.

Requested airflow is known because of Easy Select board configuration and thermostat signals. Torque is known because it is directly related to armature current which is measured by motor control. Speed is measured from its generated back EMF. This information is entered into an expression which calculates torque from speed and airflow numbers. If calculation does not match stored blower characteristics, torque is adjusted every 0.8 seconds until agreement is reached. The unit does not directly measure static pressure, but does react to a change in static to maintain constant airflow.

PROCEDURE 1—INTEGRATED CONTROLS AND MOTOR - FK4B

The motor is similar to the ECM/ICM1 used in FK4A series units, but cannot be used as a replacement without some modification to FK4A unit. The electronics of motor are built into rear of motor, deriving the name ECM/ICM. (See Fig. 3.)

An ECM/ECM/ICM is first fed high voltage AC power through the 5-pin connector. The AC power is then rectified to DC by a diode module. After rectification, DC signal is electronically communicated and fed in sequential order to 3 stator windings. The frequency of communication pulses determines motor speed. The rotor is permanently magnetized.

An ECM/ICM is powered with high voltage at all times. The motor will not run with high voltage alone. Low voltage must be applied to control plug to run motor.

PROCEDURE 2—PCB LAYOUT AND DESCRIPTION - FK4B NOTE: Layout of actual PCB is depicted in Fig. 4 and 5.

The control is a single PCB which interfaces a variable-speed motor with other system components. Power for system is supplied from a 230-vac, 60-Hz line. Class 2 voltage (24 vac nom), used for thermostat connections, is derived from a

transformer located in close proximity to control. The primary and secondary of transformer are connected to control board. The 24-vac secondary circuit includes a socket, soldered into circuit at SEC2, to receive a 5-amp automotive-type fuse.

—2—

Variations

A - Standard Unit

Minor Series

Coil Type

A - Standard

B - Modular

F - Single Piece

6th Position—Fan Coil

A - Original

Variations

A - Common Unit

⁄2 Ton)

Cooling Size

018 (1

024 (2 Ton)

001 (Multi Tons)

002 (Multi Tons)

Etc.

Electrical

A - 115-1-60

N - 208/230-1-60

S - 230-1-50

5th Position—Fan Coil

Heating Size (KW)

005

010

Etc.

10th, 11th, 12th Positions—Fan Coil

A98114

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Airflow

1 - Upflow

2 - Downflow

3 - Horizontal

Type of Unit

F - Fan Coil

4 - Multipoise

5 - Upflow/Downflow

—3—

Major Series

A - Original

B - Second Series

Unit Specifics

A - RNC

B - Standard

C - Deluxe

D - Furred in, Cased

2nd Position—Fan Coil

E - Furred in, Uncased

F - Through the Wall

G - Commercial

H - Standard Electric Furnace

J - Standard Hot Water

K - ICM Motor, High Efficiency

V - ICM Motor, Puron R-410A

X - Standard, Puron R-410A

Fig. 2—Fan Coil 16-Position Numbering System

DO NOT REMOVE

OPTIONAL SAFETY GROUND

OPTIONAL

SAFETY

GROUND

DRAIN

HOLE

Fig. 3—FK4B, FK4C and FV4A motor Motor

12345

POWER CONNECTOR

10 11 12 13 14 15 16

12345678

CONTROL CONNECTOR

A94079

MOLEX 7-PIN

CONNECTOR (1)

⁄16-IN. MALE

FASTON AMP–TYP (21) PLCS

LOW VOLTAGE

TERMINAL BLOCK

HEATER

5 AMP

ST1

MAX

0-5 600

FS1

D10

HP-EFFHP-COMFORTAC

HIMEDLO

ENH

CESS430023–01

D11

CEBD430023–01

24VDC

JW3

AUX1

JW4

AUX2

D2 D9 D4

D8 D7 D5 D6

EASY SELECT

AUX HEAT RANGE

0-30

CFM

VIO

BLU

ORN

BLK

OFF090309000

GRY

GROUND

SCREW

REQUIRED

MOTOR

0-20

1200

1000

AC/HP SIZE

042 036 030 024

TYPE

AC/HP CFM ADJUST

AC/HP

TIME

RED

SEC2 SEC1

XFORM

240

VAC

240

VAC

24VAC

0-10 800

DELAY

MOTOR

CES0130007–00

AMP 12-PIN MATE-N-LOCK CONNECTOR (1)

Fig. 4—Easy Select Board (FK4B)

HUM1

HUM2

L R C O

Y/ Y2

JW2

E W2 W3

JW1

PRINTED CIRCUIT BOARD

W2-E JUMPER 3RD STAGE

W2-W3 JUMPER 2ND STAGE

⁄4-IN. MALE FASTON AMP–TYP (9) PLCS

A94076

Connection to heater panel is made through 12-circuit connector P1. Connectionsto thermostat are madeat screw terminals. Linevoltage for motor is made through 12-circuit connector P1. Eighteen quick-connect terminals comprise field select taps for motor.

—4—

Y/Y2

ST1

JW2

JW3

JW1

JW4

SEC1

SEC2 PS1

1K 2W

AUX. HEAT

RANGE

AC/HP

SIZE

AC/HP

TYPE

AC/HP

CFM TRIM

AC/HP DELAY

123

789

10 11 12

W/W1

Y/Y2

5 – 30

1200

QC1

QC5

QC9

LOW

QC12

OFF QC15

QC2

QC6

QC16

5 – 20

1000

D10

D11

QC10

QC13

30 90

HIGH VOLTAGE

QC3

QC7

HP–COM.

MED

QC17

AUX1

HUM1

AUX2 HUM2

5 – 10

RED

QC19

QC4

QC8

QC11

QC14

QC18

0 – 5

600

024030036042

HP–EFF.

0 0

800

30 30

A94077

Fig. 5—Easy Select Board Circuitry (FK4B)

Fuse Data: 5-amp automotive-type ATC/ATO (tan)

32v 200 percent current opening time of 5 sec maximum

A. Electrical Connections

Eighteen 0.187-in quick-connect terminals are used to provide programming selections for operating modes of motor. The 5 selection modes are listed below. For additional information, refer to Easy Select Configuration Taps section.

AUX Heat Range—(Violet Wire) AC/HP Size—(Blue Wire) Type—(Orange Wire) AC/HP CFM Adjust—(Black Wire) AC/HP Time Delay—(Grey Wire)

PROCEDURE 3—SEQUENCE OF OPERATION - FK4B A. Continuous Fan Mode

The thermostat closes circuit R to G. The G signal is sent directly to motor.

B. Cooling Mode—Single Speed or 2-Speed High

Thermostat closes circuits R to Y/Y2 and R to O (heat pump only) for single speed. A circuit from R to Y1 is also required for 2-speed high. The Y/Y2 signal is sent directly to motor.

C. Cooling Mode—Two-Speed Low

Thermostat closes circuits R to Y1 and R to O (heat pump only). The Y1 signal is sent directly to motor.

D. Electric Heat Heating Mode

Thermostat closes circuit R to W2, W3, or E. The terminal block positions W2, W3, and E are tied together by jumpers JW1 and JW2. These jumpers are provided for field staging of electric

heater banks through use of thermostats. When staging is a requirement, installer cuts jumpers and wires in thermostats as is the common practice with other fan coils. To ensure motor operation if any 1 of the inputs is energized, the 3 electric heater inputs are also interlocked through diodes D1, D2, and D3 to motor W input.

E. Heat Pump Heating Mode—Single Speed or 2-Speed High

Thermostat closes circuit R to Y/Y2 for single speed. A circuit from R to Y1 is also required for 2-speed high. The Y/Y2 signal is sent directly to motor.

F. Heat Pump Heating Mode—Two-Speed Low

Thermostat closes R to Y1. The Y1 signal is sent directly to motor.

—5—

Table 1—Male/Female Quick-Connect Terminals (FK4B)

Size Female Size Male Description

0.250 X 0.032 M2 Motor line voltage connection (230 vac 60 Hz) T3 Transformer line voltage connection (230 vac 60 Hz) T2 Transformer tap storage terminal for 208-vac lead

SEC1 Secondary connection from transformer (24 vac)

This connection is common to chassis ground through eyelet marked GROUND SCREW REQUIRED.

SEC2 Secondary connection from transformer (24 vac) HUM1 Low voltage ground for humidifier option (24 vdc) HUM2 Low voltage output for humidifier option (24 vdc)

AUX1 Low voltage ground for auxiliary option (24 vdc) AUX2 Low voltage output for auxiliary option (24 vdc)

0.187 X 0.032 M1 Common connection to blower motor T1 Common connection for transformer

RED Common to R screw terminal and SEC2

Table 2—Connections on FK4B Screw Terminal Block

Screw

Description

Terminal

W2 Connection for W2 signal from thermostat W3 Connection for W3 signal from outdoor thermostat

E Connection for E signal from thermostat

Y/Y2 Connection for Y signal from thermostat

G Connection for G signal from thermostat O Connection for O signal from thermostat L This connection is a field termination for use in connecting L lines of thermostat and outdoor unit to-

gether. There is no connection of this terminal with control circuity.

Y1 Connection for low-speed compressor operation

R Connection for R signal to thermostat (24 vac) C Connection for C terminal to thermostat (24 vac common)

G. Heat Pump Heating With Auxiliary Electric Heat

Thermostat closes circuits R to Y/Y2 and/or R to Y1 with R to W2, W3, or E (and R to O in the case of defrost). See previously described modes for circuit paths. In the event that electric heating is called for by thermostat while heat pump is also operating in either heating or defrost mode, electric heating

signal will appear at motor connector pin 1 as described previously. If necessary, the motor will modify its airflow output to provide an airflow which is defined as safe for operation of electric heater.

H. CFM Select Configuration Taps

The CFM Select taps are used by installer to configure system. The motor is capable of discerning wave shapes on some of its inputs and uses this capability to modify its operation to a pre-programmed table of airflows and can be modified in response to other inputs such as the need for de-humidification.

I. Motor Control Power

The motor control power is supplied from R circuit through printed circuit runs to motor control connector pin 6, through motor control harness to motor. The C side of low-voltage control power circuit is connected by printed circuit runs to motor connector pins 4 and 5, then through motor control harness to motor.

J. Low-Voltage Circuit Fusing and Reference

The low-voltage circuit is fused by a board-mounted 5-amp automotive-type fuse placed in series with transformer SEC2 and R circuit. The C circuit of transformeris referenced to chassis ground through a printed circuit run atSEC1 connected to metal standoff marked GROUND SCREW REQUIRED.

NOTE: A ground screw must be in place or erratic motor operation can result. K. Transformer, Motor, and Electric Heater

Power Connections

The high-voltage (230-vac) power input to board is provided through electric heater connector pins 7 and 9. The high voltage is then connected through printed circuit runs to motor power connections M1 and M2 and transformer power connections T1 and T3. Transformer connection T2 is a dummy terminal used for unused primary power lead. The transformer secondary connections are made at SEC1 and SEC2 connectors.

—6—

Table 3—Connections and Connector (FK4B)

Type

Connection

Heater

Connection

Type

Pin No. Description

Connector

12-Pin Pin 1 Common to E screw terminal

Pin 2 Common to W2 screw terminal Pin 3 Common to C screw terminal, SEC1 terminal, and chassis ground Pin 4 Common to C screw terminal, SEC1 terminal, and chassis ground Pin 5 No connection Pin 6 Common to W3 screw terminal Pin 7 Common to M2 and T3 quick-connects, 230 vac input Pin 8 No connection

Pin 9 Common to M1 and T1 quick-connects, 230 vac input Pin 10 No connection Pin 11 No connection Pin 12 No connection

Motor 7-Pin Header Pin 1 Diode OR output of E or W3 or W2 thermostat signals

Pin 2 Thermostat G signal

Pin 3 Common to C, SEC1, and chassis ground

Pin 4 Common to C, SEC1, and chassis ground

Pin 5 Common to R and SEC2 (via 5-amp fuse)

Pin 6 Thermostat Y/Y2 signal

Pin 7 Thermostat Y1 signal

PROCEDURE 4—EASY SELECT CONFIGURATION TAPS - FK4B

The Easy Select taps are used by installer to configure system. The motor uses selected taps to modify its operation to a pre-programmed table of airflows. Airflows are based on system size or mode of operation and those airflows are modified in response to other inputs such as the need for de-humidification. (See Fig. 4.)

The FK4B Fan Coil must be configured to operate properly with system components with which it is installed. To successfully configure a basic system (see information printed on circuit board located next to select pins), move the 5 select wires to pins which match components used.

A. Auxiliary Heat Range

The installer must select the auxiliary heat airflow approved for application with kw size heater installed. If no heater is installed, skip this step. Each select pin is marked witha range of heaters for which airflow (also marked) is approved. For increasedcomfort select the narrowest kw range matching the heater size, for example, 0-10 for a 10-kw heater. This airflow must be greater than the minimum CFM for electric heater application with the size system installed for safe and continuous operation. Note that airflow marked is the airflow which will be supplied in emergency heat mode and heating mode on air conditioners when electric heat is primary heating source. To ensure safe heater operation in heat pump heating mode when electric heaters are energized, the motor will run the higher of heat pump efficiency airflow and electric heater airflow. The factory selection is largest heater range approved. (See Fig. 4.)

B. AC/HP Size

The factory setting for air conditioner or heat pump size is largest unit meant for application with model of fan coil purchased. The installer needs to select air conditioner or heat pump size to ensure that airflow delivered falls within proper range for size of unit installed in all operational modes. (See Fig. 4.)

C. System Type

The type of system must be selected.

1. AC—air conditioner

2. HP-COMFORT—provides same airflow as air conditioner selection (approximately 375 CFM/ton)

3. HP-EFF—provides most efficient airflow for heating and cooling modes (approximately 410 CFM/ton heating and 375 CFM/ton cooling)

The factory setting is AC. (See Fig. 4.)

D. AC/HP CFM Adjust

Select low, medium, or high airflow. The factory selection is LO. The adjust selections HI/LO will regulate airflow supplied for all operational modes, except non heat pump heating modes, +10 percent and -10 percent respectively. The adjust selection options are provided to adjust airflow supplied to meet individual installation needs for such things as noise, comfort, and humidity removal. (See Fig. 4.)

E. AC/HP Time Delay

Select desired time delay profile. Four motor operation delay profiles are provided to customize and enhance system operation. (See Fig. 4.) The selection options are:

NOTE: Selectable ON and OFF delay active in heat pump heating and cooling modes only. Auxiliary heat modes have a fixed delay profile: 0 seconds ON or 2 minutes OFF. This cannot be overridden.

—7—

1. The standard 90 sec off delay (factory setting).

2. No delay option used for servicing unit or when a thermostat is utilized to perform delay functions.

3. A 30 sec on/90 sec off delay profile used when it is desirable to allow system coils time to heat up/cool down prior to airflow. This profile will minimize cold blow in heat pump operation and could enhance system efficiency.

4. ENH, enhanced selection provides a 30 sec on/180 sec off delay at half airflow, adding comfort and efficiency.

PROCEDURE 5—TROUBLESHOOTING CIRCUIT BOARD - FK4B

Use Fig. 5 and 6 and Tables 3, 4, 5, and 6 as guides in troubleshooting PCB unless otherwise noted.

A. If Fan Will Not Turn On From Thermostat:

IF THERE IS NO HIGH VOLTAGE TO PCB:

1. Check connection of 12-pin plug from heaters to receptacle on Easy Select board. This supplies power to PCB. Be sure plug is connected properly.

2. Check sequencer number 1and plug wiring. Yellow wireshould be connected to pinnumber 9 of plug andto limit switch. Black wireshould be connected to pin number 7 of plug and to sequencer number 1.

3. Check power leads L1 and L2. If these are not receiving power, system cannot function.

IF PCB HAS HIGH VOLTAGE APPLIED TO IT:

1. Check low-voltage transformer leads (red and brown). Be sure they are wired to correct locations. (See Fig. 14) and 18.)

2. Check output voltage of transformer secondary side SEC2 and SEC1. Be sure transformer output is around 24 vac. If transformer output is zero vac and transformer is receiving correct input voltage (208v or 240v), then transformer needs to be replaced with recommended transformer. If transformer output is 24 vac, proceed to items 3 and 4.

3. Check low-voltage fuse shown in Fig. 4. If fuse is blown, replace it. The transformer cannot supply power to boardwith fuse blown orloose. If fuse blows when unit has power applied to it, the system most likely has 1 of the following problems:

a. Check control circuit for a short or miswiring problem. b. The maximum load on transformer is 40 VA. If load on transformer is excessive, the low-voltage 5-amp fuse will blow to protect

transformer. If load exceeds VA rating of transformer, a larger VA rated transformer needs to be installed. Check sequencers for excessive current draw.

c. Check wiring of heaters. If a heater is miswired, fuse may blow. If a heater is miswired, correct miswiring.

4. Check T1, T2, and T3 connections on primary side of transformer. If they are not connected properly, low-voltage terminal board cannot supply 24-v signal to energize fan motor. If transformer is receiving correct primary voltage but isnot putting out correct secondary voltage, transformer needs to be replaced.

B. If Electric Heat Stages Will Not Turn On But Fan Will Turn On:

1. Check wiring of sequencers. Pay particular attention to high- and low-voltage wiring of sequencers.

2. Check plug wiring to make sure that it is wired correctly.

3. Check voltage to sequencer. Sequencer number 1 receives a 24-vac signal. If it is receiving correct voltage, check to see if sequencer is closing. If sequencer is not closing but is receiving correct voltage, replace sequencer. If sequencer is closing, check high-voltage wiring as discussed in items 1 and 2.

IF THERE ARE BLOWN DIODES:

If diodes are blown, it is probable that electric heater plug is miswired. Correct miswiring. NOTE: Board will need to be replaced if diode is bad.

IF TRACES ARE OVERHEATED ON BACK OF PCB:

Usually whenever there isa trace blown on PCB,it means either there hasbeen a high-voltage short orhigh voltage has been appliedto low-voltage circuit. This can be prevented by making sure PCB is wired correctly before PCB has power applied to it.

C. If PCB Fuse Keeps Blowing:

When low-voltage fuse blows, it means transformer would have blown if fuse had not been in circuit to protect it. The fuse usually blows when there is a high current drawn on transformer, high voltage applied to low-voltage circuit, or a direct secondary short. When there is a high current drawn on transformer, it is most likely because transformer has been shorted or system is trying to draw more VA than transformer rating allows. When fuse blows because of high voltage, the system has mixed high- and low-voltage signals.

1. Check transformer and thermostat wiring. (See Fig. 4 and 6.) Be sure transformer is not shorting out because thermostat wires are miswired.

2. Check wiring of sequencers. (See Fig. 4 and 6.) Be sure low-voltage and high-voltage wiring are connected to proper sequencers.

3. Check VA draw on transformer. If VA draw is more than VA rating of transformer, fuse will blow. If this is the case, replace transformer with one that has a higher VA rating and meets system specifications.

PROCEDURE 6—TROUBLESHOOTING FAN MOTOR - FK4B A. If Motor Does Not Run:

1. With power turned off, check all plugs and receptacles on circuit board and at motor for any deformation that may cause a bad connection. Be sure all plugs are placed fully seated.

—8—

THIS COMPARTMENT MUST BE CLOSED EXCEPT FOR SERVICING

BLOWER MOTOR

ROTATION

30KW 1PH SCHEMATIC DIAGRAM

HVTB

YEL

CB/FU4

YEL

CB/FU2

FIELD POWER WIRING

FU6

YEL

BLU

GND

LS6

LS5

LS4

LS3

LS2

LS1

YEL

PLUG 1

DISCONNECT PER NEC

HTR6

BLK

12 11

ORN

SEQ2

SEQ3

SEQ 3

BLK

10 9

BLK

SEQ 2

BLK

SEQ 1

BLK

BLU

BLK

SEQ1

BRN

GRY

BLK

VIO

BRN

YEL ORN GRN

HTR5

HTR4

HTR3

HTR2

HTR1

RED

SEE RATING PLATE

FOR VOLTS & HERTZ

BLK

BLKBLK

BLK

123456789101112

PLUG 2

24567

RED BRN VIO

(SEE NOTE 1)

FU5

CB/FU3

CB/FU1

BLK

NOT SUITABLE FOR USE ON SYSTEMS

NE CONVIENT PAS AUX INSTALLATIONS

SCHEMATIC DIAGRAM

FIELD POWER WIRING

BLU

ORN

BLK

GRY RED

BRN

RED

TRAN

BLK

COMMON

RED

BLU

BLK

(SEE NOTE 3)

YEL BLK

VIO

A–C HP–COMFORT HP–EFF

0/30 30/30 30/30 0/0

SEC2

YEL

BLU

RED

YEL

54321

PLUG 3

PLUG 4

SEE RATING PLATE

FOR VOLTS & HERTZ

(SEE NOTE 1)

COOLING CONTROL WIRING

COOLING CONTROL ONLY

AUX HEAT RANGE

AC/HP SIZE

TYPE

AC/HP CFM TRIM

MED HI

AC/HP DELAY ON/OFF

RECP 2

SEC1

RECP 1

T2 T3

GRN/YEL

YEL

BRN

RED

BLU

BLK

GRY

BLK

CAUTION:

EXCEEDING 150V TO GROUND

ATTENTION:

DE PLUS DE 150 V A LA TERRE

DISCONNECT PER NEC

GND

PLUG

AUX1 HUM1

AUX2 HUM2

24VAC

LVTB

JW2 JW1

OLRY

INDOOR THERMOSTAT

PCB

RECP 3

VIO

ORN

RED

VIO

192103114125136147158

BRN

ICM

RECP 4

Y E

(SEE NOTE 2)

O L R

HPTB

1Y0W2

NOTES:

1. Use copper wire only between disconnect switch and unit.

2. Connect (Y) to (Y), (C) to (C), etc. in pattern shown.

3. Transformer primary leads: BLUE 208V, RED 230V.

4. To be wired in accordandce with NEC and local codes.

5. If any of the original wire, as supplied, must be replaced, use the same or

6. Replace low voltage fuse with no greater than 5 amp fuse.

7. Fuse is wired in series between transformer SEC2 and low voltage "R" circuit.

8. 20KW heater uses one double pole LS on middle top element.

9. 18, 24 and 30KW heaters use double pole limit switches.

10. Largest heaters are shown, smaller heaters will have fewer elements and components.

11. 1 phase heaters are shown wired for single supply circuit. Multiple supply circuits may be wired directly to fuse/C.B.'S.

Fig. 6—Typical FK4B Wiring Diagram with 6-Element Heater

equivalent type wire.

—9—

MARKED TERMINAL UNMARKED TERMINAL FIELD POWER WIRING PLUG AND RECEPTACLE PCB BREAKOFF JUMPER AUXILIARY

AUX

PRINTED CIRCUIT BOARD

PCB

HEAT PUMP TERM BRD

HPTB

LOW VOLT TERM BRD

LVTB

SEQUENCER

SEQ

HEATER

HTR

HIGH VOLTAGE TERMINAL BOX

HVTB

HUMIDIFIER

HUM

- LEGEND -

LIMIT SWITCH

ICM

FAN MOTOR

TRAN

TRANSFORMER

GND

EQUIPMENT GROUND

FUSE

RECP

RECEPTACLE

CIRCUIT BREAKER

LOW VOLTAGE FUSE

320486 - 301 REV. C

A94078

Table 4—FK4B Motor Control Test Values

(With 16-pin connector at motor unplugged)

Terminals Jumpered Volt Meter on 16 PIN

Harness Plug

Volt Meter on 7-pin

Easy Select Board Plug

Voltage

+-+ -

R to W1 or W2 Pin 2 Pin 1 or 3 Pin 1 Pin 3 or 4 12vdc

R to Y1 Pin 6 Pin 1 or 3 Pin 7 Pin 3 or 4 24vac

R to Y/Y2 Pin 14 Pin 1 or 3 Pin 6 Pin 3 or 4 24vac

R to G Pin 15 Pin 1 or 3 Pin 2 Pin 3 or 4 24vac

2. Verify that there are approximately 230v at terminals M1 and M2. If not, determine if high voltage is entering board. It enters through black and yellow wires at pins 7 and 9 in 12-pin plug.

3. Verify that there is a low-voltage control signal to motor.The motor receives its controlsignals through the 7-pin motor plug P2. The voltage output of each pin in plug will be different for each mode of operation. Table 4 lists circuit board screw terminals that have 24 vac present (powered by thermostat) and lists voltage that is present at each pin of 7-pin plug for each operating mode. Tests should be taken between points listed and common (C screw terminal). If all values of any 1 of operating modes checks OK and motor fails to run, then motor is defective and should be replaced.

B. If Motor Does Not Run Smoothly:

First verify that the cause is not an out of balance or damaged blower wheel. If it is not blower wheel, motor is defective and should be replaced.

C. If Motor Shaft Does Not Rotate Smoothly:

When manually turning shaft of ECM/ICM, the shaft does not rotate smoothly. The shaft has steps during rotation referred to as motor cogging. The cogging is caused by permanent magnets passing each pole of motor. However, shaft should not require excessive force to turn. If shaft is VERY difficult to turn, motor control or bearings have failed and motor must be replaced.

D. If Motor Does Not Stop Running

1. Check for good ground between motor ground lead and transformer common lead.

2. If motor continues to run, remove all thermostat wires. If motor stops, check thermostat wiring for short.

3. If motor continues to run, remove the 7-pin plug. If motor continues to run after 2 minutes, replace motor.

PROCEDURE 7—CONDENSED VERSION OF TROUBLESHOOTING FK4B MOTOR AND CONTROLS

This section provides a quick summary of howto troubleshoot the FK4B.If more information is needed, refer to appropriate sectionsof this service manual.

+ MOTOR

- If motor is hard to turn manually, but turns freely, replace module.

- If motor does not run, check the components listed below according to their instructions.

- If motor runs in some operation modes and not in others, check for a good ground connection between motor ground lead and circuit board

screw marked "ground screw" and check the room thermostat and wiring harness according to instructions listed in Table 4.

- If motor does not stop running, remove the 7-pin plug from circuit board. If motor continues to run, replace motor. If motor stops running after 2 minutes, it is either the circuit board or thermostat causing the problem. Test whether thermostat is at fault by disconnecting it from the board.

+ CIRCUIT BOARD

- Check 5-amp fuse.

- Check for 230v between terminals M1 and M2.If no voltage ispresent, check power toboard. 230-v power enters the board through the black and yellow lead in the 12-pin plug.

- Check for 24v between SEC1 and SEC2. If no voltage is present, check the transformer.

- Check for burn traces or burnt components. If burn spots are present, replace board.

+ ROOM THERMOSTAT

- Remove thermostat wires from the circuit board.

- Jumper screw terminals (1 at a time) R-G, R-Y/Y2, R-Y1, and R-W2. If motor runs in all cases, thermostat or thermostat wiring is bad. If motor does not run, or runs in some cases but not in others, continue by checking the wiring harness.

+ WIRING HARNESS

- Shut off power to unit.

- Remove 5-pin plug from motor.

WARNING: ELECTRICAL SHOCK HAZARD Failure to follow this warning could result in personal injury or possible equipment damage. Never remove 5-pin high voltage plug from the motor with the power on.

- Remove 16-pin plug from motor.

- Replace 5-pin plug and turn on power. —10—

- Check for 24vbetween pin-1 and pin-12 on the 16-pin plug. (See Fig. 7.) If no voltage is present, replacewiring harness. If voltage is present,

16 15 14 13 12 11 10 9

8 7 6 5 4 3 2 1

16-PIN PLUG

A94375

Fig. 7—Wiring Harness 16-Pin Plug

jumper screw terminal R-Y/Y2 on circuit board and check for 24v between pin 1 and pin 12 and pin 1 and pin 14 on 16-pin plug. (See Fig. 7.) If voltage is present, replace harness.

- If 24v is present on both pins, the motor or module is bad. Replace motor.

PROCEDURE 8—ACCESSORIES (FK4B) A. Electronic Air Cleaner (EAC)

Familiar 230-vac EAC control/power signal EAC1 and EAC2 is not available, because the motor blower motor used in the FK4B Fan Coil is controlled by low-voltage signals. This signal is replaced by a 24-vdc signal which is provided at circuit board terminals AUX1 and AUX2. (See Fig 16.)

This signal is present when either G or W is present and is active in all heating and cooling modes. Because 24-vdc relays may not be readily available to installer, a kit exists, KFAIR0101ACR, containing a 24-vdc relay which mounts directly inside EAC cabinet. User-supplied 110 vac is switched by relay to power air cleaner when G or W are present. (See Fig. 8)

MOUNT FLUSH WITH THESE TWO EDGES

A93216

Fig. 8—Mounting KFAIR0101ACR Relay Kit

In heat pump applications, the G signal is present in both cooling and heating modes, permitting EAC to be controlled from G signal only. For this application, a user-supplied 24-vac relay can be driven by G terminal eliminating need for relay kit.

B. FK4B De-Humidify Mode NOTE: Humidistat must open on humidity rise.

Latent capacities for systems using the FK4B Fan Coil are better than average systems. If increased latent capacity is an application requirement, the FK4B can be wired to provide this requirement by adjusting its airflow in response to standard humidistat input. Fig. 9 illustrates the wiring connections to activate de-humidify mode. Carefully consult product airflow data for cooling and dehumidifying mode.

HUMIDISTAT

RED WIRE

FROM ICM2

MOTOR

HUMIDISTAT WIRING FOR DE-HUMIDIFY MODE

TO PCB TERMINAL MARKED 'RED'

A93215

Fig. 9—Humidistat Wiring for De-Humidify Mode

FV4B, FK4D, FK4C, FV4A, AND 40FKA

The FK4C fan coil was introduced several years before the FV4A and 40FKA models. All three units contain the motor and use the same control board. The 40FKA was introduced as part of the Comfort Heat Pump system and is identical to the FK4C except it is factory supplied with a Thermidistat Control. Both the 40FKA and FK4 R-22 units with a factory supplied R-22 TXV. Other than the pressure differences in the Puron system, all three units are constant airflow machines and operate the same way. The FV4B and FK4D include the added benefits of low sweat/low leak cabinet.

—11—

OPTIONAL SAFETY GROUND

DRAIN HOLE

12345

POWER CONNECTOR

10 11 12 13 14 15 16

12345678

OPTIONAL SAFETY GROUND

CONTROL

POWER

ENDSHIELD

DRAIN HOLE

CONTROL CONNECTOR

A98201

Fig. 10—FK4C, FV4A, and 40FKA motor/ECM2.3 Motor

Constant Air Flow

Unlike fan coils using induction motors where static pressure affects airflow, these fan coils are constant airflow units. The blower delivers requested airflow regardless of static pressure. Consult fan coil Product Data for static pressure limits. The motor/ECM2 is pre-programmed and contains airflow tables for all modes of operation. Blower characteristics (requested airflow, torque, and speed) are known from laboratory testing. If any 2 characteristics are known, the third is defined.

Requested airflow is known from Easy Select board configuration and thermostat signals. Torque is known because it is directly related to stator current which is measured by motor control. Speed is measured by counting back EMF pulses from stator windings. This information is entered into an expression which calculates torque from speed and airflow numbers. If calculation does not match stored blower characteristics, torque is adjusted until agreement is reached. This calculation and adjustment is performed every 0.8 sec while motor is in operation. There is no direct measure of static pressure, but unit does react to a change in static to maintain constant airflow. A change in pressure will result in a change in stator speed and torque. The motor will begin to adjust on the next sampling, calculate new desired speed and torque, and adjust as necessary.

PROCEDURE 1—INTEGRATED CONTROLS AND MOTOR ECM / /ECM2)

An motor/ECM2 is fed high voltage AC power through the 5-pin connector. (See Fig. 10.) The AC power is then internally rectified to DC by a diode module. After rectification, DC signal is electronically communicated and fed in sequential order to 3 stator windings. The frequency of these commutation pulses determines motor speed. The rotor is permanently magnetized.

An motor/ECM2 is powered with high voltage at all times. The motor will not run with high voltage alone. Low voltage must be applied to control plug to run motor.

ECM/ICM 2 CONTROL POWER The motor/ECM2 control power is supplied from R circuit through printed circuit runs to motor control connector pin 8, through motor control

harness to motor. The C side of low-voltage control power circuit is connected by printed circuit runs to motor connector pins 9, 10, and 11 then through motor control harness to motor.

LOW-VOLTAGE CIRCUIT FUSING AND REFERENCE The low-voltage circuit is fused by a board-mounted 5-amp automotive-type fuse placed in series with transformer SEC2 and R circuit. The C

circuit of transformer is referenced to chassis ground through a printed circuit run at SEC1 connected to metal standoff marked. NOTE: The PCB must be mounted with 2 screws and motor ground lead secured to blower housing or erratic motor operation can result. TRANSFORMER, MOTOR, AND ELECTRIC HEATER POWER CONNECTION Transformer high voltage supplied from electric heater package or high voltage leads through 12-pin heater connector plug/recp2. The

motor/ECM2 power connections are made at the transformer primary terminals. The transformer secondary connections are made at SEC1 and SEC2 connectors.

COMFORT HEAT PUMP SYSTEM In 1998, the ComfortHeat Pump System was introduced in whicha 40FK, FK4 or FV4fan coil can be installed. This introduced many new features

for enhanced comfort. To activate these modes, they must be configured into the indoor control. The Thermidistat Control and current zoning have the capability of both of these modes.

To initiate these operating modes, the control drops out the G signal to reduce airflow for extra comfort in heating and maximum dehumidification in cooling. This must be kept in mind while troubleshooting these fan coils. Be aware that a cooling or heating input without the G input energized will result insignificantly lower airflow than may be expected. When verifying airflow in normal heating and cooling modes (including emergency heat in newer motors), remember that G must be energized to achieve full airflow.

—12—

Table 5 — Motor & Modules Capable of Comfort Heat / SuperDehumidfy Modes

Model Motor Part Number Replacement Module

Part No.

FK4C, FV4A, 40FKA001, 002 HD44AE128, 131, 125* RMOD44AE128, 131

FK4C, FV4A, 40FKA003 HD44AE129, 132, 127* RMOD44AE129, 131 FK4C, FV4A, 40FKA005 HDD44AE130, 133, 126* RMOD44AE130, 133 FK4C, FV4A, 40FKA006 HD46AE243, 244, 242* RMOD46AE243, 244

*These motors will not adjust airflow with G in electric heat modes.

The FK4 has some earlier series that were produced before the Comfort Heat Pump System was introduced. Some of the motors will not have the programming that slows the fan down on a loss of the G signal. The following units are factory programmed for Super Comfort Heat and SuperDehumidify Modes:

40FKA/B.........ALL

FV4A/B..........ALL

FK4C..........Series A through E (1995-1997)NONE

FK4C..........Series F reduces airflow in heat pump heating and cooling modes only (not in electric heating modes).

FK4C/D..........Series G reduces airflow in all modes

FK4A..........NONE with original motor. If upgraded to motor/ECM2 motor, it may have programming

FK4B..........NONE with original motor. Replacement motor or module may have programming.

IF an original motor or module has been replaced, it may have Super Comfort Heat and SuperDehumidify capability.

PROCEDURE 2—PCB LAYOUT AND DESCRIPTION (FK4, FV4, 40FK) NOTE: Layout of actual PCB is depicted in Fig. 11 and 25.

The Easy Select Board is the interface between the ECM motor and other system components. The board offers choices of electric heater size, outdoor unit size and type, comfort or efficiency settings, on and off delay profiles, and continuous fan speed. The installer should select the correct size of components that are being installed in each installation. If no selections are made, the factory default settings are for the largest heater, largest outdoor unit, AC system type, nominal airflow adjust, and 0/90 time delay.

NOTE: Outdoor unit model should have an ARI rating with the variable speed fan coil. Some outdoor unit models will not work properly with this fan coil.

Power for system is supplied from a 230-vac, 60-Hz line. Class 2 voltage (24 vac nom.), used for thermostat connections, is derived from transformer located in close proximity to PCB. The 24-vac secondary circuit includes 5-amp automotive-type fuse in SEC2 circuit.

Connection to heater panel is made through 12-pin connector PL-1. Connections to thermostat are made at screw terminals. Twenty-one pin terminals comprise field select taps for motor.

Fuse Data: 5-amp automotive-type ATC/ATO (tan)

32v 200 percent current opening time of 5 sec maximum

A. Electrical Connections

Twenty-one 0.110-in pin terminals are used to provide programming selections for operating modes of motor/ECM2. The 6 selection modes are listed below. For additional information, refer to Easy Select Configuration Taps section.

AUX Heat Range—(Violet Wire) AC/HP Size—(Blue Wire) Type—(Orange Wire) AC/HP CFM Adjust—(Black Wire) AC/HP Time Delay—(Grey Wire) Continuous Fan—(Yellow Wire)

PROCEDURE 3—SEQUENCE OF OPERATION (FK4, FV4, 40FK) A. Continuous Fan Mode

The thermostat closes circuit R to G. The unit delivers the airflow selected for fan only operation.

B. Cooling Mode—Single Speed or 2-Speed High

Thermostat closes circuits R to G, R to Y/Y2 and R to O (heat pump only). A circuit R to Y1 is required for 2-speed high operation. Airflow delivered the airflow selected by AC/HP SIZE selection and CFM ADJUST selection.

C. Cooling Mode—Two-Speed Low

Thermostat closes R to G and R to Y1 and R to O (heat pump only). Unit delivers 2-speed low airflow for AC/HP SIZE and CFM ADJUST selected.

D. Cooling + Dehumidify Mode (Thermidistat or Comfort Zone II-B and Single-Speed Outdoor Unit Installed)

J1 jumper must be pulled from Easy Select Board. Control closes R to G, R to Y/Y2, and R to O (heat pump only) and open R to DH. Dehumidification is active when 24vac is removed from DH terminal. Unit delivers 20% less airflow.

E. SuperDehumidify Mode (Thermidisat or Comfort Zone II-B indoor control, Single-Speed Outdoor Unit)

This mode is only activated by the indoor control when COOL to DEHUMIDIFY and SUPERDEHUMIDIFY are configured at the control and there is a call for dehumidfication without a call for cooling. The control closes R to Y/Y2, R to O (heat pump only) and opens R to DH and R to G. This signals the fan coil to run at minimum airflow for maximum humidity removal. The control will cycle the equipment 10 minutes on and 10 minutes off until satisfied.

—13—

SEC1

EASY SELECT

AUX/HEAT KW/CFM

0-30

0-20

1075

875

VIO

AC/HP SIZE

036 030 024 018

BLU

SYSTEM TYPE

AC HP-COMFORT HP-EFF

ORN

BLK

WHT

YEL

AC/HP CFM ADJUST

NOM LO HI

ON/OFF DELAY

309000ENH

CONTINUOUS FAN

LO MED HI YEL

SEC2

0-10

725

0-5

625

5 AMP.

MAX.

D5D2

AUX1 HUM1

AUX2

YYWWX

STI

HUM2

Y/Y

AUX1

HUM1

AUX2

HUM2

GRY

PL1

HEATER/MOTOR

24VAC

GRY

CES0130035-00

A96430

Fig. 11—Easy Select Board

SYSTEM DIAGRAM

HEATER/MOTOR

987654321

/4"

DIODE LOGIC

121110

SEC1 SEC2

/4"

Y/Y

5 AMP

AUX HEAT

KW/CFM

AC/HP

SIZE

SYSTEM

TYPE

AC/HP CFM

ADJUST

ON/OFF

DELAY

CONTINUOUS

FAN

A96431

Fig. 12—Easy Select Board Schematic

F. Heat Pump Heating Mode — Single Speed or 2-Speed High

Thermostat closes R to Y/Y2 and R to G. A circuit R to Y1 is required for 2-speed high operation. The unit delivers airflow selected by AC/HP SIZE selection and CFM ADJUST selection. Selected delay profile is active in this mode.

G. Heat Pump Heating Mode — 2-Speed Low

Thermostat closes R to G and R to Y1. Unit delivers 2-speed low airflow for AC/HP SIZE and CFM ADJUST selected. Selected delay profile is active in this mode.

—14—

Table 6—Connections and Connector (FK4C)

Type

Connection

Heater

Connection

Type

Pin No. Description

Connector

12-Pin Pin 1 Common to screw terminal G

Pin 2 Common to screw terminal Y/Y2 through diode D3 Pin 3 Common to Y1 through diode D2 Pin 4 Common to W2 screw terminal Pin 5 Common to W2 screw terminal Pin 6 Common to screw terminal W1 screw terminal Pin 7 Common to W1 screw terminal Pin 8 R 24VAC

Pin 9 Common to transformer C Pin 10 Common to transformer C Pin 11 Common to transformer C Pin 12 Common to DH screw terminal

H. Non-Staged Auxiliary Heat with Heat Pump Heating Mode

Thermostat should already have closed R to G, R to Y2 for heat pump heating operation. With J2 jumper in place, energizing either W1 or W2 will produce the W2 airflow. This is the greater of heat pump heating and auxiliary heat airflow plus an additional 15%. The elected delay profile is not active in this mode.

I. Staged Auxiliary Heat with Heat Pump Heating Mode

The auxiliary heat can be staged by removing the J2 jumper that ties W1 and W2 terminals together. Staging can be done by using outdoor thermostats or by using the Intelligent Heat Staging option where the indoor control can be configured for 3-stage electric heat. The unit will automatically adjust airflow when the different stages of heat are energized. The airflow delivered will depend on the heat pump size selected and electric heat size selected. The greater of the two airflows will be delivered. The selected delay profile is not active in this mode.

J. Electric Heat without Heat Pump

Thermostat closes R to W andthermostat should be set up to energize G with W. This is due to the Super Comfort Heat programmingin the motor. Energizing W without G will result in 25% lower airflow delivery. The selected delay profile is not active in this mode.

K. Super Comfort Heat Mode

This is a special heating mode only available on FK4, FV4, and 40FK fan coils combined with aThermidistat Control or Comfort Zone II-B. When this option is selected, the indoor control will monitor the outdoor temperature. The control will drop the G signal to the fan coil when the outdoor temperature is between 10° and 40° F. This triggers the motor to slow to approximately 213 CFM per ton. The heaters will stage as needed during this mode and the motor will adjust airflow as required. Below 10° F., theW1 control output will automatically energize on a call for heat. The motor/ECM2 power connections are made at the transformer primary terminals. The transformer secondary connections are made at SEC1 and SEC2 connectors.

PROCEDURE 4—EASY SELECT CONFIGURATION TAPS

The Easy Select taps are used by installer to configure system. The motor/ECM2 uses selected taps to modify its operation to a pre-programmed table of airflows. Airflows are based on system size and mode of operation and those airflows are modified in response to other inputs such as the need for de-humidification. (See Fig. 11.)

The FK4, FV4, and 40FK Fan Coils must be configured to operate properly with system components with which it is installed. To successfully configure a basic system (see information printed on circuit board located next to select pins), move the 6 select wires to pins which match components used, along with homeowner preferences.

A. Auxiliary Heat Range

The installer must select the auxiliary heat airflow approved for application with kw size heater installed. Each select pin is marked with a range of heaters for which airflow (also marked) is approved. For increased comfort select the narrowest kw range matching the heater size, for example, 0-10 for a 10-kw heater. This airflow must be greater than the minimum CFM for electric heater application with the size system installed for safe and continuous operation. Note that airflow marked is the airflow which will be supplied in emergency heat mode and heating mode on air conditioners when electric heat is primary heating source. To ensure safe heater operation in heat pump heating mode when electric heaters are energized, the motor/ECM2 willrun the higher of heat pump airflow and electricheater airflow. The factory default selection is largest heaterrange approved. (See Fig. 11.)

B. AC/HP Size

The factory default setting for air conditioner or heat pump size is largest unit meant for application with model of fan coil purchased.The installer needs to select air conditioner or heat pump size to ensure that airflow delivered falls within proper range for size of unit installed in all operational modes. (See Fig. 11.)

C. System Type

The type of system must be selected.

1. AC—air conditioner (approx. 350 CFM/ton)

2. HP-COMFORT—provides lower airflow than air conditioner selection (approximately 315 CFM/ton) in heating mode. In cooling mode supplies 350 CFM/ton.

—15—

Table 7—Typical Operating Modes

Operating

Terminals Energized

Mode

Heat Pump Only Heating R, Y/Y2, G, DH

Heat Pump Only Heating + Super Comfort Heat Mode R, Y/Y2, DH

Heat Pump Heating + Auxiliary Heat (non-staged) R, Y/Y2, G, DH, W2

Cooling R, Y/Y2, G, DH, O Cooling + Dehumidification R, Y/Y2, G, 0 Cooling + Superdehumidify R, Y/Y2, O

3. HP-EFF—provides same airflow for heat pump heating and cooling modes (approximately 350 CFM/ton).

The factory setting is AC. (See Fig. 11.)

D. AC/HP CFM Adjust

Select low, nominal, or high airflow. The factory selection is NOM. The adjust selections HI/LO will regulate airflow supplied for cooling and heat pump heating modes only, +15 percent and -10 percent respectively. The adjust selection options are provided to adjust airflow supplied to meet individual installation needs for such things as noise, comfort, and humidity removal. (See Fig. 11.)

E. ON/OFF Delay NOTE: ON/OFF Delay is active only in cooling and heat pump only heating modes. In auxiliary heat mode or emergency heat mode, the ON

delay is 0 seconds and the OFF delay is fixed and cannot be overridden. Select desired time delay profile. Four motor operation delay profiles are provided to customize and enhance system operation. (See Fig. 11.) The

selection options are:

1. The standard 90 sec off delay (factory setting 0/90).

2. No delay option used for servicing unit or when a thermostat is utilized to perform delay functions (0/0).

4. ENH, enhanced selection provides a 30 sec on/150 sec at 70 percent airflow and no off delay.

F. Continuous Fan

Select desired Continuous fan profile LO, MED, or HI. Airflow are provided to customize and enhance the continuous fan functions. (See Fig.

11.) The possible selections are:

1. LO—provides 50% of Y/Y2 Cool airflow.

2. MED—provides 65% of Y/Y2 Cool airflow (71% on 006 model).

3. HI—provides 100% of Y/Y2 Cool airflow.

The factory setting is LO. NOTE: If applied to two-speed unit, do not select continuous fan as HI since low speed cooling will also run at HIGH airflow and insufficient

dehumidification may result.

G. Easy Select Board Jumpers

J1 - This jumper must be pulled to activate dehumidification mode. The jumper connects R to DH. With the jumper in, the DH terminal is always energized. With the jumper pulled, the DH terminal is de-energized. A control such as the Thermidistat must be used to supply the 24-volt signal when there is no call for dehumidification, and turn off the 24 volts when there is a call for dehumidfication.

J2 - This jumper activates heat staging. The jumper connects the W1 and W2 terminals together. If either is energized, W2 airflow is delivered. With the jumper pulled, there are separate airflows for W1 and W2.

H. Airflow Delivery

These units deliver airflow depending on the system size selections and operating mode. The thermostat energizes a combination of terminals on the Easy Select Board which tells the motor what CFM to deliver. The following are typical operating modes and the terminals that should be energized on the Easy Select Board.

NOTE: The DH terminal on the Easy Select Board is for dehumidification. It is de-energized on a call for dehumidification. I. Variable Speed Motor Logic Sequence:

The ECM motors in these fan coils are programmed to deliver a variety of airflows. The motor goes through: COOLING

The nominal cooling airflow for these fan coils is 350 CFM per ton. Selecting the HI adjust tap increases the airflow to 400 CFM per ton. The LO tap decreases airflow to 315 CFM per ton. The low adjustment is only active during normal cooling mode. Removing the signal from the DH terminal reduces the airflow to 80% of cooling airflow. Removing the G signal for Superdehumidify reduces the airflow to 50% of cooling.

HEATING The base heat pumponly heating airflow is determinedby the SYSTEM TYPE selectionon the Easy Select Board. If HP-EFFICIENCY is selected, the airflow is the same as Cooling. IF HP-COMFORT is selected, the airflow is 315 CFM per ton. The airflow will adjust up if necessary when auxiliary heating is required. When both theY/Y2 and W1 orW2 terminals are energized,the motor will run the higher of the heat pump or electric heat airflows. During Super Comfort Heat mode, the indoor control removes the G signal from the board. This slows the motor to 75% of heat pump airflow. If the CFM adjust is set to LO, it will deliver 67.5% of heat pump airflow during Super Comfort Heat mode.

—16—

PROCEDURE 5—TROUBLESHOOTING A. Troubleshooting Easy Select Board (FK4, FV4, 40FK)

IF TRACES ARE OVERHEATED ON BACK OF PCB:

Usually whenever there is a trace broken on PCB, it means either there has been a high-voltage short or high voltage has been applied to low-voltage circuit. This can be prevented by making sure PCB is wired correctly before fan coil has power applied to it.

If PCB Fuse Keeps Blowing:

When low-voltage fuse blows, it means transformer would have blown if fuse had not been in circuit to protect it. The fuse usually blows when there is a high current drawn on transformer, high voltage applied to low-voltage circuit, or a direct secondary short. When there is a high current drawn on transformer, it is most likely because transformer has been shorted or system is trying to draw more vac than transformer rating allows. When fuse blows because of high voltage, the system has mixed high- and low-voltage signals.

1. Check transformer and thermostat wiring. (See Fig. 11 and 13.) Be sure transformer is not shorting out because thermostat wires are

miswired.

2. Check wiring of relays. (See Fig. 11 and 13.) Be sure low-voltage and high-voltage wiring are connected to proper sequencers.

3. Check VA draw on transformer. If VA draw is more than VA rating of transformer, fuse will blow. If this is the case, replace transformer

with one that has a higher VA rating.

B. Troubleshooting Common Problems

Airflow Too Low: Y1 instead of Y/Y2 on single-speed air conditioner or heat pump application. Y1 input is only for 2-speed applications. Using this terminal will

deliver about 60% of full cooling airflow. Wrong Easy Select Board selection. Selecting an outdoor unit or electric heater smaller than actually installed will result in low airflow for the

application. G not energized with call for cooling or heating. This triggers Super Comfort Heat or SuperDehumidify mode which delivers 50% of cooling

airflow. J1 jumper pulled with no Thermidistat or dehumidistat installed. The J1 jumper ties the DH terminal to R and is installed at the factory. When

pulled, a Thermidistat or dehumidistat supplies a 24-volt signal to DH when there is no call for dehumidification (reverse logic). When there is no signal on DH, the motor reduces airflow to 80% for better dehumidification.

Airflow Too High:

Wrong Easy Select Board selection. Fan coil is factory set for the largest outdoor unit and largest electric heater. Select sizes that are actually installed.

Continuous fan set too high for 2-speed applications. Set to MED or LO.

Motor Will Not Stop:

Allow time for off delay to time out. In units built before serial number 0101A, any W call will have a 2 minute off delay independent of delay selection. This is programmed into the motor and cannot be overridden.

In units built after 0101A, the off delay on any W call is 1 minute and cannot be overridden. Some power stealing thermostats could bleed enough voltage to cause motor to run slowly when there is no heating or cooling call. Disconnect

thermostat wires and wait 2 minutes to see if motor stops. If it stops, replace thermostat, or install resistor per thermostat installation instructions.

Motor Will Not Start:

See following section, ″Troubleshooting motor/ECM2 Motor and Controls″

C. Troubleshooting motor/ECM2 Motor and Controls

CAUTION: ELECTRICAL OPERATION HAZARD Failure to follow this caution may result in equipment damage or improper operation. High voltage is always present at motor. Disconnect power to unit before removing or replacing connectors or servicing motor. Wait at least 5 minutes after disconnecting power before opening motor.

The ECM/ICM motor used with this product contains two parts: the control module and the motor winding section. Do not assume the motor or module is defective if it will not start. Go through the steps described below before replacing control module, Easy Select Board or entire motor. The control module is available as a replacement part.

D. If Motor Turns Slowly:

1. It is normal operation to run noticeably slower if G terminal is not energized in cooling or heat pump heating modes.

2. Attach blower access panel. Motor may appear to run slowly if access panel is removed.

E. If Motor Does Not Run:

Turn power off, wait 5 minutes and check the following:

1. With power turned off, check 5 amp fuse on Easy Select Board

2. Check all plugs and receptacles for any deformation or corrosion that could cause bad connections. Be sure plugs are fully seated.

CAUTION: ELECTRICAL OPERATION HAZARD Failure to follow this caution may result in equipment damage or improper operation. DO NOT remove or apply 5-pin plug on motor with power on. Arcing could occur which can damage control module.

—17—

THIS COMPARTMENT MUST BE CLOSED EXCEPT FOR SERVICING

BLOWER MO TOR

ROTATI ON

20KW 1PH SCHEMA TIC DIAGRAM

FIELD POWER WIRING DISCONNECT PER NEC

FU1

YEL

BRN

VIO RED

PLUG 1

CB2

CB1

YEL

Com

ORN B

RED

BLK YE

GRN

ORN

GRY

VIO

RED

WHT

YEL

GRN

PLUG 4

BLU

TRAN

208V

BLK

1 2 3

11 10

YEL

9 9

YEL

12 11 10

9 8 7 6 5 4 3 2 1

SEE RATING PLATE FOR VOLTS & HERTZ

230V

5 4 3 2 1

VIO

WHT

BLK

GND

INTERNAL PROTECTION MAY BE EITHER FUSES OR CIRCUIT BREAKERS

HTR3

LS3

HTR2

LS2

HTR1

LS1

HTR4

LS4

BLK

11 11

RED

BRN

BLK

VIO

BLU

ORN

BLK

YEL

WHT

PLUG 3

GRN/YEL

GND

BRN

ORN

BLU

BLK

SEE NOTE #1

CB2

RELAY 3

BLK

RELAY 2

BLK

RELAY 2

BLU

VIO

BLU

ORN

BLK

WHT

YEL

CFM

PL1

BLK

8 RELAY 1

BLK

SEC2SEC1

AUX HEAT KW/CFM

AC/HP SIZE

SYSTEM TYPE

AC HP-COMFORT HP-EFF

AC/HP CFM ADJUST

NOM

ON/OFF DELAY

CONTINUOUS FAN

LO MED HI YEL

HEATER / MOTOR

SEE INSTRUCTION FOR INSTALLATION

CB1

BLK

RELAY 1

22 VDC COIL

REC

VIO

ORN

23 2

PCB

0 0

RECP 3

ICM

RECP 4

FU2

FU4

BLK

RED

GRY

16 1

GRY

LABEL (2)

RELAY 2

22 VDC COIL

T D R

RELAY 3

22 VDC COIL

R E C

BRN

FU3

AUX1 HUM1

HUM2

AUX 2

24 VAC

GRY

NOT SUITABLE FOR USE ON SYSTEMS EXCEEDING 150V TO GROUND

NE CONVIENT PAS AUX INSTALLATIONS DE PLUS DE 150 V A LA TERRE

CAUTION:

ATTENTION:

LEGEND

COM

COMMON

LOW VOLTAGE FUSE

ICM

FAN MOTOR FIELD POWER WIRING

LINE FUSE

GND

EQUIPM EN T GR O U ND

HVTB

HIGH VOLTAGE TERM BLOCK

HTR

HEATER

REC

RECTIFIER

LIMIT SWITCH MARKED TERMINAL PLUG AND RECEPT A CLE

PCB

PRINTED CIRCUIT BOARD

TRAN

TRANSFORMER

RECP

RECEPT ACLE

CIRCUIT BREAKER

RELAY

TDR

TIME DELAY RECTIFIER

FIELD POWER W IRING

COOLING CONTROL ONLY

FIELD

POWER

L1 L2

WIRING

YEL

208/240VA C 24VA C

BRN

Y/Y

PLUG 2

4 4

RECP 2

HTR1

LS1

60A 60A

OUTDOOR UNITINDOOR THE RMOSTAT

RELAY 1

REC

RELAY 2

TDR

RELAY 3

REC

NOTES:

1. USE COPPER WIRE (75*C MIN) ONLY BETWEEN DISCONNECT SWITCH AND UNIT .

2. TO BE WIRED IN ACCORDANCE WITH NEC AND LOCAL CODES.

3. TRANSFORMER PRIMARY LEADS, BLUE 208V, RED 230V.

4. IF ANY OF THE ORIGINAL WIRE, AS SUPPLIED, MUST BE REPLACED, USE THE SAME OR EQUIVALENT TYPE WIRE.

5. REPLACE LOW VOLTAGE FUSE WITH NO GREATER THAN 5 AMP FUSE.

6. DUAL CIRCUIT WIRING SHOWN.

7. USE 60 AMP CLASS K FUSES ONLY, FOR REPLACEMENT.

8. CONNECT R TO R, G TO G, ETC., SEE OUTDOOR INSTRUCTION FOR DET AILS.

L4 L3

CB1

11 7

HTR3

BLK

HTR4

CB2

60A 60A

SYSTEM TRANSFORMER: 40.0VA

FAN COIL/HEATER: 8.2VA

REMAINING V A AVAILABLE: 31.8VA

COMPONENT ARRANGEM ENT

HTR2

RED

24 V

BRN

FU4

FU2 FU1 FU3

PCB

PL1

GND

LS2

L4 L2 L1 L3

SEC2SEC1

HEATER / MOTOR

24VAC

ICM

PLUG 2

RECP 2

COM

TRAN

208 V 230 V

Y/Y

G O C

16 16

325653-101 REV . B

Fig. 13—FK4C, FV4A, and 40FKA Wiring Diagram with 20kw heater after heater serial # 1900A56372

—18—

A00178

Turn power back on and check the following:

3. Check for 24vac on SEC1 and SEC2. If no voltage is present, check transformer.

4. Verify that approximately 230vac is present at motor.

5. Verify low voltage control signals to motor according to procedure below.

Use following procedure to check low voltage signals:

The ECM motor in these fan coils receive low voltage signals from the Easy Select Board through the wiring harness assembly. The combination of pins energized at the motor determines the speed the motor will run. The procedure below isolates the fan coil from all external devices such as a thermostat, condensing unit, humidifier or electronic air cleaner. There is also a specific troubleshooting example to demonstrate the process. Table 7 provides information needed to verify that the correct voltages are present at the motor and the Easy Select Board.

THERMOSTAT:

1. Remove all thermostat and accessory wires from Easy Select Board.

2. On Easy Select Board, jumper screw terminals (1 at a time): R-G, R-Y/Y2, R-Y1, R-W1, R-W2. If motor runs in all cases, check thermostat outputs. Thermostat wires may be broken, or thermostat may be miswired, configured incorrectly, or defective. If the motor does not run, or runs in some cases, but not others, continue this procedure to check wiring harness and circuit board.

WIRING HARNESS:

1. Remove 16-pin plug from motor.

2. Check for appropriate voltages on 16-pin connector with screw terminals jumpered. (See Table 6.)

3. If signals check correctly, and motor does not run, inspect wiring harness for loose pins or damaged plastic that could cause poor connections.

4. If connections are good, either control module or motor is defective.

5. If proper signals are not present, check circuit board using procedure below:

12-PIN PLUG (PL-1) ON EASY SELECT BOARD:

1. Completely disconnect wire harness from Easy Select Board.

2. Jumper the screw terminals one at a time; R-G, R-Y/Y2, R-Y1, R-W1, R-W2 and check for appropriate voltages on the Easy Select Board pins. If proper signals are not present, replace Easy Select Board. If proper signals are present at the pins and not at 16-pin connector to the motor, the wiring harness is defective.

TROUBLESHOOTING EXAMPLE: Motor is not running on a call for heat pump heating after jumpering the Easy Select Board screw terminals as described in Thermostat section

above: With all thermostat wires removed from Easy Select Board, place a jumper wire between R and Y/Y2 low-voltage screw terminals on the Easy

Select Board

1. Check Table 8 for pin number on 16-pin connector associated with the Y/Y2 signal. The correct pin is #14. The far right column of Table 8 shows that (-) 12vdc should be present between pin #14 and pin #1 (common) on the 16-pin connector.

2. Set meter to readDC voltage. Place meter leads between pins #1 (common) and #14 and check for(-) 12vdc. If signal ispresent, the problem is in the module or motor. If signal is not present, the problem is either in wiring harness or Easy Select Board.

These steps can be repeated for other modes of operation.

To check Easy Select Board:

1. Leave jumper wire in place between R and Y/Y2.

2. Check Table 8 under ″Volt Meter on Easy Select Board Plug″ column and row for pin #14 on motor plug to see pin # on Easy Select Board that should have voltage. The correct pin is #2. The column on far right will show voltage that should be present between pin #2 and pin #9 (common).

3. Place meter leads between pins #2 and #9 on Easy Select Board and check for (-) 12vdc.

4. If voltage is present, the wiring harness is bad. If not, the Easy Select Board is bad.

Verify Motor Winding Section:

Before proceeding with module replacement, check the following to ensure motor winding section is functional. With control module removed and unplugged from winding section:

1. The resistance between any 2 motor leads should be similar.

2. The resistance between any motor lead and the unpainted motor end plate should be greater than 100K ohms.

If motor winding fails one of these tests, it is defective and must be replaced.

F. Accessories

AUXILIARY TERMINALS The AUX and HUM terminals on the Easy Select Board are tied directly to the G terminal, and provide a 24-vac signal whenever the G terminal

is energized (See Fig. 5 and Fig. 6). During Superdehumidify mode, the G signal is not present and the auxiliary terminals are not energized. If the installation includes theuse of this operating mode, do not use theseterminals to control accessories. SeeElectronic Air Cleaner and Humidifier sections for further information.

—19—

Table 8—FK4C Motor Control Test Values

(With 16-pin connector at motor unplugged)

Terminals Jumpered Volt Meter on 16 PIN

Harness Plug

Volt Meter on 12-pin

Easy Select Board Plug

Voltage

+-+ R to W1 Pin 2 Pin 1 Pin 7 Pin 9 24vac R to W2 Pin 13 Pin 1 Pin 4 Pin 9 24vac

R to Y1 Pin 6 Pin 1 Pin 3 Pin 9 (-)12vdc

R to Y/Y2 Pin 14 Pin 1 Pin 2 Pin 9 (-)12vdc

R to G (LO) Pin 15 Pin 1 Pin 3 Pin 9 Ovac

R to G (MED) Pin 6 Pin 1 Pin 3 Pin 9 (-)12vdc

R to G (HI) Pin 14 Pin 1 Pin 2 Pin 9 (-)12vdc

FAN COIL

AUX1

AUX2

(C)

RED

(G)

RED

24 VAC RELAY

230 VAC OR 115 VAC BRANCH CKT

GND HOT NEUT

BLK

GRN

BLK

COM

WHT

TO EAC

BLK

A98625

Fig. 14—KFAIR0201ACR Relay Kit

Wiring Schematic

ELECTRONIC AIR CLEANER CONNECTIONS The AUX1 and AUX2 terminals are not always energized during blower operation, as described above. When using an electronic air cleaner with

the FV4 fan coil, use Airflow Sensor . The airflow sensor turns on electronic air cleaner when the fan coil blower is operating. HUMIDIFIER / HUMIDISTAT CONNECTIONS Easy Select Board terminals HUM1 and HUM2 are provided for direct connection to the low-voltage control of a humidifier through a standard

humidistat. These terminals are energized with 24vac when G thermostat signal is present. Alternately, the 24-vac signal may be sourced from the W and C terminal block connections when electric heaters are used as primary heating source. When using a Thermidistat™ Control, Zone Perfect Plus, or Comfort Zone II, the 24-vac signal may be source directly from the Thermidistat HUM terminal.

G. FK4, FV4, and 40FK Dehumidify Mode NOTE: Humidistat must open on humidity rise.

Latent capacities for systems using the FK4, FV4, and 40FK fan coils are better than average systems. If increased latent capacity is an application requirement, the field wiring terminal block provides connection terminals for use of a standard humidistat. The FK4, FV4, and 40FK fan coils will detect the humidistat contacts opening on increasing humidity and reduce its airflow to approximately 80 percent of nominal cooling mode airflow. This reduction will increase the system latent capacity until the humidity falls to a level which causes the humidistat to close its contacts. When the contacts close, airflow will return to 100 percent of the selected cooling airflow. To activate this mode, remove jumper J1 and wire in a standard humidistat. (See Fig. 15.) Carefully consult product airflow data for cooling and dehumidification modes.

FE4

Model FE4A fan coil is designed to be installed with a communicating user interface. The FE4A fan coil will provide airflow at a rate commanded by the User Interface.The nominal airflow/ton rate is350 CFM/ton. The User Interfacewill modify the commanded airflowunder certain operating modes. Refer to the User Interface literature for further system control details. This fan coil will not respond to commands from a common thermostat except under certain emergency situations explained in this document.

PROCEDURE 1—ELECTRONICALLY COMPUTED MOTOR (ECM2.5)

An ECM2.5 is fed high voltage AC power through the 5-pin connector. The AC power is then internally rectified to DC by a diode module. After rectification, DC signal is electronically communicated and fed in sequential order to 3 stator windings. The frequency of these communication pulses determines motor speed. The rotor is permanently magnetized.

—20—

+ 44 hidden pages

PURON FA4, FB4, FC4, FD3, FE4 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual