Bryant FA4A User Manual

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Service Manual

FAN COIL UNITS

F A X N o , 3 1 7 2 4 0 5 6 6 2

P . 0 0 1

; - IM'

■ S': ■ ■ Tis

■■■'-- ■ ■

f ABLE OF CONTENTS

... ■ -i'

SAFETY considerations.................................................................

iNTROPucTioi^ ....................................................^

UNIT irtENTIUCATiON

PRODUCT OFEERMG..........................................................................3

FAN MOTOR STEBfi TATS.........................

FA4A, FB4A, FC4B, AKD FH4A CIRCUIT BOARD

FUNCTIONJ^TROORLE^^ 3^6

■ Printed GirciiitBoifd jfPCB) CqmpijSntjjt ^Layout and Description

• Unit Functions ■_. ■ , fj I

• Troubleshooting PCB 'i; ''

ELECTRIC HEATER FUNCTION

AND TROUBLESHOOTiNG^„„„„;„,,........................................6-7

*-Description of Electric Heater Components

- Troubleshooting KFA and KFB Scries Electric Heaters FK4B FAN COIL DESCRIPTION

■ I ^'J'f AND TROUBLESHOOTING

• Integrated Controls and Motor (ICM2)

■ • PCB Layout and Description

• ,St(5iience of Operation

• Easy Select Configuration Taps ' : "

• Troubleshooting PCB " >

• Troubleshooting ICM2 ' ■ it'

■ Condensed Version of Troubleshooting Motor

. and Controls

• Accessories . , THERMOSTATIC EXPANSION VALVEis (TXV) ' Problems Affecting "DCV PISTON BODY CLEANING OR REPl^'CEMENT LIQUID TUBE STRAINER

coil/condensate fan removal

AND replacement....................................L.............................16-17

- A-Coil Units ‘ Slope Coil Units CARE AND MAINTENANCE

■ Filter Assembly.

• Cooling Coil, Drain Tan, and Condensate Drain

• Blower Motor and Wheel ■■iC ;

FFIA/FFIB SERVICE AND TROUBLESHOOTING

• Fan Motor ■

• Electric Heater Service

• Cleaning or Replafcmg Refrigerant Flow^Control Device

• Liquid Tube Strainer .■ iyi:.,.

' Sequence of Operation if 2

• Care and Maintenance

FD3A SERVICE AND TROUBLESHOOTING...........................21-23

• Fan Motor - ;

• Electric Heater Service

- Cleaning or Replacing Refrigerant Flow-Control Device

• Liquid Tube Strainer

• Care and Maintenance

FG3A SERVICE AND TROUBLESHOOTING...........................23-24

- Service

• Maintenance

........

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.................................... 17-lS

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18-21

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15-16

1-3

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FA^A, FB4A, AND FC4B SMART HEAT CIRCUIT BOARD

IhJNCTION AND TROUBLESHOOTING

• PCB Component Layout, Description, and Function

■ Unit Functions

• Smart Heat Operation

• Electrical Operating Sequences and Troubleshooting

, i SAFETY CONSIDERATIONS

Ij^proper installation, adjustment, alteration, service, maintenance, of use Can cause explosion, fire, electrical shock, or other conditions which may cause personal injury or property damage. CpnSult a qualiSed installer, service agency, or your distributor or blknch for information or assistance. The qualified installer or agency must use factory-authoriied kits or accessories when modifying thiS;pfoduct. Refer to the individual installation instruc tions packaged With the kits or accessories for detailed informa tion..

Follow all Safety codes. Wear safety glasses and work gloves. Use quenching cloth for bracing operations. Have fire extinguisher avmlable. Read these instructions thoroughly and follow all warnings or cautions attached to the unit. Consult local building m'dës and National Eectricai Code (NEC) for special installation requirements-

It is important to recognize safety information. This is the safety-alert symbol^j^ , When you sec 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 CAU TION. These words are used with the safety-alert symbol, DANGER identifies the most serious hazards which will result in severe

^I3anc0ls; SM03-1

Fig. 1—Typical Fan Coll

...............................

SM03-2

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2jitl- Position—Fan CoiF

A- RNC B-Standard C - Deluxe D - Furred in, Cased E - Furred in. Uncased'

F - Through Ihe Wall G- Commercfal H - Standard .Electric Fumaoe

J - Standard Hot Water .

K- ICM Motor, High EffTciericy

V - VariabJe Speed ^

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MObÈL UNIT SIZE DESCRIPTION CABINET

FA4ANF 01S-060 FB4ANB 042-070 Multtpoise Modular FB4ANF 016-060 Multipoise Single Piece

FB4ASB 042-060

FB4ASF 010-060

FC4BNB 042-070 Multipoise Modular FC4BNF 024-060 FD3ANA 018-030 Horizontal Single Piece

FF1A/FF1BNA 010-030 Vortical

FG3ANA 024, 036, 048, 060 Horizontal/Small Commercial Single Piece FH4ANB FH4ANF 001-004 Multipoles Single Piece FK4BNri 005, 006 Multipoise Modular FK4BNF 001-004 Multipolee

NOTE: Multipoise units are approved for upflow, doivnflow, and horizontal left and right applications.

UTC TECH PUB

table 1—product offering

003, 004 Multi poiss Modular

TABLE 2—FAN MOTOR SPEED TAPS

MODEL

FA4A 018-036 2 Black FA4A 042-060 3 Black Blue Red Yellow

FB4A 018-070 FC4B 024-070 3 Black Slue Red Yellow FD3A 016-030 2 Black — Red Yellow

FF1A/FF1B 018-030

FG3A 024, 036, 048, 060 1* FH4A G01-0D4 3 Black Blue Red Yellow

*Belt drive,

UNIT SIZE

NUMBER OF

SPEEDS

3 Black Blue Red Yellow

personal injury or death. WARNING signifies hazards which could result in personal ityury or death. CAUTION is used to identify unsafe practices which would result in minor personal

injury or product and property damage.

INTRODUCTION

The "F" Scries fan coil units arc designed for flexibility in a variety of applications, meeting upflow, horizontal, or downflow require ments. Units are available in 1-1/2 through 5 ton nominal cooling capaddes. Factory-authorized, field-installed electric heater pack ages are available in 3 through 30 kilowatts.

WARNING: Before installing or servicing fan coil,

always turn off all power to unit. There may be more than

1 disconnect switch. Turn off accessory heater power if applicable. Electrical shock can cause personal injury or death.

UNIT IDENTIFICATION

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

FA4A, FB4A, FC4B, AND FR4A CIRCUIT BOARD

FUNCTION AND TROUBLESHOOTING

This section of the service manual describes the CES0130003 PCB by examining the functional operation of the PCB compo nents.

I. PRINTED CIRCUIT BOARD (PCB) COMPONENT LAYOUT AND DESCRIPTION

Layout of the actual PCB is depicted in Fig. 3.

L The low-voltagc ¡stripped leads are used to connect the 24-v

side of transformer

to indoor thermostat and outdoor

section.

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Multipolar

Multlpolne

50 Hz

MuitipoiSQ

50 Hz

Multipoise

HIGH

SPEED

Black

—

MEDIUM

SPEED

—

— — —

LOW

SPEED

'Blue

Red Violet

2. A 5-amp fuse is used to protect the low-voltagc transformer secondary.

3. The fan relay is controlled by thermostat and turns fan on and off,

4. A plug is used as the connection for PCB power and electric heaters. Note the pin numbers on plug,

5. A time-delay relay circuit keeps fan motor running for 90

sec after G is dc-energiied.

II. UNIT FUNCTIONS

A- Transformer

1. Proper Wiring of Transformer Primary or High Side

Yellow wire from Molex plug is wired to C terminal on transformer and black wire from PCB relay (normallyopeij) terminal is wired to 2Q5V or 230V terminal on transformer. Units are factory wired at 230V terminal

2. Proper wiring of Transformer Secondary or 24-v Side Red wire of transformer is wired to T terminal on PCB and

brown wire of transformer is wired to C terminal on PCB.

NOTE: T terminal on PCB is used to protect transformer. T

terminal is connected through the fuse to R terminal on PCB.

B. Indoor Fan

1. Wiring

Indoor fan motor yellow lead is wired to C terminal on transformer. The red, blue, or black speed lead is wired to 5PT terminal On fan relay part of PCB. Units are factory wired on medium speed (blue lead connected),

NOTE: Unused fan speed leads must be capped or taped off to

prevent direct short to cabinet surface.

Single Piece

Modular

Single Piece

COMMON

Yellow

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FIg. 3—Fan Còli

2. Functional Control a. Thermostat and Relay Control

When thermostat calls for the fan in cooling, heat pomp, heating, or fan-only mode, a 24-vdc signal is sent to relay. This causes the relay to close its nonnally-opcn contacts, turning On fan. When thermostat no longer calls for the fan, the signal sent to relay is turned off and relay opens causing fan to turn off after a 90-sec fan-off delay,

b. Sequencer Interlock

The fan will also Operate whenever there is a call for electric heat, even if fan relay is nOt energized. This happens because fan is interlocked with first stage of electric heat through the normally-dosed contact of fan relay.

NOTE: The fan interlock is only connected to first stage electric

heat W2, W3 and E do not contain an interlock with fan. See outdoor thermostat Installation Instructions when electric heat Staging is desired;

C. Electric Heat

When thermostat calls for electric heat, a 24-vac signal is sent to PCB through WZ, causing first stage to turn on. W3 and E also receive signal if wired in with WZ. The signal sent to WZ causes J5r$t stage to turn on. If W3 and E arc not wired to W2, the sequencers can be controlled individually to stage additional electric heat. The sequence control is described in the following Section;

1. W2 When thermostat sends a signal to WZ, a Z4-vac signal is

applied across sequencer number f, causing it to close after a short delay. When sequencer number 1 closes, first stage of electric heal is energized. In straight electric heat, fan is

also energized through the nonnally-doscd contacts of fan relay. In cooling, heat pump, or manual fan mode, fan will already be running since fan relay would have been energized. When thermostat stops calling for electric heat, the 24-'Vac signal to sequencer number 1 turns off and

sequencer opens after a delay of 60 to 90 sec. When sequencer opens, first stage of heat turns off along with fan, providing thermostat is not calling for the fan.

2. W3 When a signal is sent to W3, a 24-vaO Signal to sequencer

number 2 causes sequencer to dose, with Second stage of electric heat turning on after a short delay. The 24-vac

F A X N o , 3 1 7 2 4 0 5 6 6 2

PCB BLOCK WIRINS

LOW

VOLTAGE FUSE

Printed-Circuit Boafd , 2

-4-

signal applied to sequencer number iJ chuses fan -tb;opkate. Timing is Such that'sequchc'or liuinB'if FWiIf'iiirn:tii.h:'before sequencer number 2. Whem, sigriifl to'WS' is turned off,

sequencer number 2 op,ens;;^^aiter a short 'delay. tf^.W^Z is also satisfied, first stage of.,dectriC'heat and^-fimwiy ais^o tum off, providing thermostat is not calling for the fan.

3, E ■'

When thermostat ..sends, a signal :iDrB^ ' a' 24-v~ac signalris sent to sequencer number 3, The 24^Wc; sighhl' applied to

sequencer number 3 turns" on third'stagcof'clcctric heat. The 24-vac signal applied to sequencer number 1 turns on first stage of electric heat'arid fan. ’^hen 'thermostat stops calling for electric heat,' the signartO'Sequ£d£efs I, 2, and 3

are turned off/^ahd sequdhfcefs b'|fieh;'''Th'il5''caii&es''dw^ heat to turn off with fan providihg'lheriniti^Iat'i^'hdt calling for the fan, ^ ^ .

NOTE: Electric heaters are factory wired with alj stages tied

together. If independent staging is desired, cpnsul|, outdoor ther^ mostat Installation Instructions. ./

III. TROUBLESHOOTING PCB . ■ > 2

Use wiring schematic shown in Fig, 4 as a guide in troubleshooting PCB unless otherwise notedv ■ ■ —

A. If Fan Will Not tum On ffom TherWost^i: ' ^

IF THERE IS NO HIGH VOLTAGE TO PCB:

1. Check plug/receptacle connection. This supplies power from heaters to PCB. Be sure plug is connected properly.

, 2-, Check sequencer number X and plug wiring. Yellow, wire

should be connected to pin number 9 of plug and to limit switch. Black wire should be Connected to pin number 7 of plug and to sequencer number 1.

3. Check power leads Cl and L2. tf these are not receiving power, system cannot function.

IF PCB HAS HIGH VOLTAGE APPLIED TO IT;

1, Check low-voltagc transformer leads R (red) and C

(brown). Be sure they are wired to correct locations,

2. Check output voltage of transformer secondary side R (red) and C (brown). Be sure transformer output is between IS and 30 vac. If transfbmicr output is incorrect and transfonner is reqeiving correct input voltage (208v or 230v), then transformer needs to be replaced with recommended transformer. If no problem exists with transformer secondary, proceed to items 3 and 4.

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) . 3 1 7 2 4 0 5 6 6 2

P ,

f THIS COMPARTMENT MUST BE CLOSEP EXCEPT TOR SERVICING

1 BLOWER MOTOR |

.„.J ROTATION

CboKW 1PH SCHEMATIC DIAGRAM)

NOT SUITABLE FOR Ü5É ON SYSTElilS EXCEEOINS leovTO GROUND

в 117

£0B/240VAC 24VAC 24VAC

3 11 7 U

LEGEND

U 3 2 8 1 4

ATTENTION:

MARKED TERMINAL PLUS AND RECEPTACLE

PflINTSD CIRCUIT BOARP

SEQUENCER TRANSFORMER UNMARKED TERMINAL RECEPTACLE

CIRCUIT BREAKER

Я p e 1 i

CAUTION: ^

USE COPPER WIRE (/S'C MIN) ONLY BETWEEN D[SCCNNECT 3WIT01 AND UNFT,

TO BE WIRED IN ACCORDANCE WITH NEC AND UDCALOODES, i, TRANSPORMER PRIMARY LEADS, BLUE 20aV, RED 230V. A IF ANY OFTHE ORIGINAL WIRE, AS 5UPPUED. MUST BE REPLACED,

USE THE SAME OR RQUIVACPJTTYPE WIRE.

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

20KW HEATER USES ONE DOUSLg POLE LS ON MIDDLE TOP ELEMENT. 10, Й4 AND 30KW HEATERS USE СЮиВ1^ POLE UHIT SWITCHES. LARGEST HEATERS ARE SHOWN, SMALLER HEATSR5 Will HAVE FEWER ELEMENTS AND COMPONENTS. 1 PHASE HEATERS ARE SHOWN WIRED FOR 8INSL£ SUPPLY CIRCUIT.

10. USE SO AMP CLA38 К FUSSS ONLY. FOR REPLACEMENT.

11, (3) SPEED MOTOR SHOWN. OPTIONAL (2) SPEED MOTOR иЗЕЗШ(ВЦ^ AND LOW

(BLU OR RED). 13, CONNECT fi TO R, S TO G, ETC.. SEE OLnDOQR INSTRUCTION FOR DETAILS, la. IF WIRE CRIMP IS REMOVED AN EMEHOENCV HgATftgUY 16 REQUIRED.

(SEE OUTDOOR-THERMOSTAT (NSTRUCTIOMS)

3, Check low-voltage fuse shown in Fig. 3. Jf fuse is blown,

replace it. The transformer cannot supply power to board with fuse bjowfl or loose. If fuse blows when unit has pow‘er applied to it, the systejs most likely has 1 of the following problems:

a. Check all 24-v wiring for an electrical short. b. The maximum load on transfonner is 40 va. If load ott

transformer is excessive, the low-voltage 5-anjp 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.

32121A-101 REV. C

pig. 4—^Wiring Diagram

4. Check connections on primary side of transfonner. If they

■ 9 ■■ '■■ ■ 1

C, Check wiring of heaters. If a heater is miswired, fuse

arc not connected properly, the low-voltage terminal board cannot supply the 24-v signal to energize fan relay. If transfonner is receiving correct primary voltage hut is not

putting out correct secondary voltage, transformer needs to

be replaced.

2DB;S4aVAC J 24VAC 24VAC

may blow. If a heater is miswired, correct miswiring by comparing it to heater wiring label.

3^ 6

1 4

A9434G

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AÏÏG/14/2008/THÜ 03:46 PM UTC TECH PUB

FAX No. 317 240 5662

P. 006

fe. If Electric Hegt Stages Will Not Turn On But Fan Will

Turn On:

IF THERE IS NO HIGH VOLTAGE TO PCB:

1. Check plug connection between heaters and board. This supplies power to transformer and fan. Be sure plug is connected properly.

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

plug and to sequencer number 1-

3- Check incoming high-voltage power leads, tf these arc not

receiving power, system c&undt function.

IF PCB HAS HIGH VOLTAGE APPLIED TO IT;

1, Check low-voltage transformer leads R (red) and C

(brown). Make sure they are wired to correct location. The

unit will not function without proper connections.

2. Check output voltage of transformer secondary side R (red) and C (brown). If transformer output is low (less than 18 vac), reifer to items 3 and 4 of previous If PCB Has High Voltage Applied To It section.

IF TRACES ARE OVERHEATED ON BACK OF PCB:

Usually whenever a trace is blown on PCB, it means cither 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 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 riot been in circuit to protect it. The fuse usually blows when there is a high Current draw on transformer, high voltage applied to low-voltagc circuit, Or a direct secondary short. When there is a high current draw 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 wiring of sequencers as shown in Fig. 4, Be sure transformer is not shorting out because thermostat wires arc miswired.

2. Check wiring of sequencers as shown in Fig. 4. Be sure low-voJtagc and high-voltage wiring is 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 spccifícationS-

D. If F^n Runs Continuously:

1. If PCB has no low-vohage power, check blue and black fan leads. These may be switched at sequencer,

2. If PCB has lowwoltage power, check fan relay to see if it is , opening and closing. It may be stuck in the normally-closed position due to debris in relay.

E- Transformer Failure:

1. Check 208-v and 230-v transformer connections. They may

be miswired.

ELECTRIC HEATER FUNCTION AND

TROUBLESHOOTING

This section describes KFA and KFB series electric heaters by examining the functional operation of these heaters,

I. DESCRIPTION OF ELECTRIC HEATER COMPONENTS

A. Limit Switch

The limit switch is a temperature-sensitive control whose function is to prevent System from, overheating in abnormal conditions. The temperature settings often vary from heater to heater due to

variations in airflow patterns and clement radiant heat conditions. The devices arc sized to remain on-line under heat pump condi tions (11 ST air off coil) and minimum CFM;, but trip to prevent outlet air conditions above 200T or excessive component or duct temperatures.

The device itself consists of a bimetallic disc, which when overheated "snaps through" to open a normaliy-closed highvoltage, high-current switch. When system temperatures cool sufficiently, the switch will automatically reset to its closed position. Normal failure mode for this switch is open.

If a limit switch has been determined to be défective, NEVER BYPASS THE LIMIT SWITCH. When replacing limit Switch, ensure that it is replaced with a limit switch of identical opening température and closing differential. Limits switches are typically

color coded to identify their range.

B. Sequencer

The sequencer is essentially a thermally activated time-delay relay normally activated by low-voltage control signals from thermostat. The typical sequencer is a 1- Or 2-pole normally-open device which energizes within 10 to 30 sec after application of control signal and de-energizes 60 to 90 sec after control signal is removed. In simplistic terms, the sequencers which we use are nothing more than normally-open limit switches which sit on top of a small

resistive heater. When voltage is applied to this heater, a positive temperature coefficient resistor (BTC), heat is supplied to a bimetallic disc which "snaps through" and closes switchTbe time required for PTC to heat to a suffiejeut point controls ON timing of device. The time required for disc to cool down when

power is removed controls OFF time of device. The PTC can be varied to provide varied timing. Typically a short ON equates to a long OFF,

Because this is a thermally-activated device, ambient conditions affect the ON/OFF cycle. Higher ambient temperature means shorter ON times and longer OFF times.

These sequencers may be "ganged up" to 3 On a common mounting plate to control up to 6 heater elements. In this situation, PTCs arc different in each sequencer to provide a staged QN of a minimum of 10 sec between each sequencer — 3 stages of 2 elements since

the KFA and KFB Series .Деа1ег8 use , sequencers in which both switches of the 2-polc sequencer close simultaneously. Older models used sequencers which had a minimum delay of fO sec between each switch.

Application of these devices is such that the first switch ON not only turns on first heater element, but also ensures that indoor fan is energized, because first ON is last OFF. This ensures fan remains ON until the last heater de-energizes-

с. Positive Temperature Coefficient (PTC)

The PTC heater is essentially a resistor. It will operate on either AC or DC voltages. It should be noted that because resistance of PTC increases as, it, heats, initial current inrush is higher than its steady state condition.

II. TROUBLESHOOTING KFA AND KFB SERIES

electric heaters

A. Discolored Wire Insulation at Tormincl

Check quick-coimect terminal at discoloration. Connection may be loose, creating a high resistance through connection point.

B. Fuse Failure

1, Check for shorted wire. Replace wire. Never try to fix wire

using electrical tape,

2. Check shorted element. If element is shorted, replace heater.

C. No Heat

1, Check fuse for failure. If fuse has failed, refer to Fuse

Failure section.

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F A X N o , 3 1 7 2 4 0 6 6 6 2

2. Check for faulty transformer. Check output voltage of transformer secondary side R (red) and C (brown). Make sure output is between IS and 30 vac. If output voltage is

low pud input voltage teçtç normaJ, replace transformer.

3. Check for miswired heater plug harness,

4. Check limit switch or sequencer failure. These switches

should have failed in open position. If output voltage is zero

V, replace Switch,

D. Heater Will Not Turn Off

1. Check low-voltage wiring for miswire.

2. Check for shorted elements to ground.

3. Replace sequencer contacts. They may be stuck closed.

E. Nuisance Trips

1. Check for low airflow due to dirty filters» blocked registers, Of Undersized duct.

2. Check blower motor and wheel for proper operation. Excessive current draw of motor will cause internal over load to trip.

3. The fan Speed may be low.

FK4B FAN COIL DESCRIPTION

AND TROUBLESHOOTING

The FK4B is similar to the discontinued FK4A only in that they both have integrated controls and motor (ICM) and their own

Special circuit board. The greatest difference between the 2 models

is the way each goes about delivering air. 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 difference is that the FK4B motor reacts to changes in system static pressures to

mainiain 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 ÏCM2 is pre-programmed and contains airflows for al) modes of operation. Blower characteristics (airflow, torque, and spccd-vs-static pres sure) are known from laboratory testing. If any 3 characteristics are known, the fourth iS defined.

Requested airflow is known because of Easy Select board con

figuration 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 0.6 sec until agreement is reached. The unit does not directly measure static pressure, but does react to a^ change in static to maintain constant ■ airflow.

I. INTEGRATED CONTROLS AND MOTOR (ICM2)

The ICM2 is similar to the ICMI used in FK4A series units, but cannot be used as ,a replacement without some modification to FK4A unit. Consult SMB 93-0052 for motor conversion kit. The electronics of motor are built into rear of motor, deriving the name ICM, (Sec Fig, 5.)

An ICM is first fed high voltage AC power through the 5-pin connector. The AC power is then rectiEcd to DC by a diode module. After rectification, DC signal is electronically communi

cated and fed in sequential order to 3 stator windings. The frequency of.communication pulses dctemiines motor speed. The rotor is permanently magnetized.

An 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-

II. PCB LAYOUT AND DESCRIPTION NOTE: Layout of actual PCB is depicted in Fig, 6 and 7,

The control is a single PCB which interfaces a variable-speed

ICM2 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. Connection to heater panel is made through 12-circuit connector

PI. Connections to thermostat are made at screw terminals. Line voltage for ICM2 is made through 7-circuit connector P2. Eighteen quick-connect 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 ConnectiDna

Eighteen 0,lS7-in quick-connect terminals arc used to provide programming selections for operating modes of ICM2. The 5 selection modes № 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)

III, SEQUENCE OF OPERATION A. Continuous Fan Mode

The thermostat closes circuit R to G, The G signal is sent directly to ICM2.

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-spced high. The Y/Y2 signal is sent directly to 1CM2.

C. Cooling Mode—Two-Speed Low

Thermostat closes circuits R to Y1 and R to O (heat pump only). The Yl signal is sent directly to ICM2.

D. Electric Heat Heating Mode

Thermostat doses circuit R to W2, W3, or E,

The terminal block positions W2, W3, and E arc tied together by jumpers JWl 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 arc also interlocked through diodes Dl, D2^ and D3 to motor W input.

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

Thcmiostai doses circuit R to Y/Y2 for single speed. A dreuit

from R to Yl is also required for 2-speed high. The Y/Y2 signal is sent directly to ICM2,

F. Heat Pump Heating Mode—Two-Speed Low

Thermostat doses R to Yl. The Yl signal is sent directly to ICM2.

G. Heat Pump Heating With Auxiliary Electric Heat

Thermostat doses circuits R to Y/Y2 and/or R to Yl with R to W2,

W3, Or E (and R to 0 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 deEned as safe for operation of electric heater.

-7-

A U G / 1 4 / 2 0 0 8 / T H U 0 3 : 4 7

UTC TECH PUB

F A X N o , 3 1 7 2 4 0 5 6 6 2

OPTIONAL SAFETY GROUND

Ш®®®Qp

POWER CONNECTOR

CONTROL CONNECTOR

И. CFM Select Configuration Taps

The CTM Select taps are used by installer to configure system. The

ICM2 is capable of discerning wave shapes on some of its input?

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. 1CM2 Control Power

The ICM2 control power is supplied from R circuit through printed-circuit runs to motor control connector pin 6|, through rnotor control harness to motor. The C side of low-vpltagc 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 transformer is referenced to chassis ground through a printed-circuit run at SECl 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 con-

A94079

ICM2 Motor

nections Ml and M2 and transforníer power connections T1 and T3. Transformer connection T2 is a dummy terminal used for unused primary power lead. The transformer Secondary conriections are made at SECl and SEC2 connectors.

IV, EASY SELECT CONFIGURATION TAPS

The Easy Select taps are used by installer to configuire system. The ICM2 uses selected taps to modify its operation to a pre

programmed table of airflows. Airflows are based on system size

or mode of operatibh and thosd airflows arc modified in response to other inpüts stich as the need for de-humidifícation. (Sec Fig. 6.)

The FK4B Ran 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 with a range of heaters for which airflow (also marked) is approved. The heater installed must fall within range selected for safe and continuous operation. It is appropriate to mention 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

-8-

A U G / 1 4 / 2 0 0 8 / T H U 0 3 : 4 7

UTC TECH PUB

MOLEX 7-PIN-

CONNECTOR (1)

LOW VOLTAGE

TERMINAL BLOCK

EASY SELECT

AUX HÈAT HANQE

СГН 'ÎÏÔT

Ac/Ht> SIZE

(H2 [ DIS [ D3D I OM

TYPE

№<ШГйКГ NPOT

QHNI GiQ

, ......

0=0 0=0

AC/HP. ÛFM ADJUST

Ifl UCD HI

\ &€> \ &e>

AC/HP TIME DELAY

„ 1 MUHI

Sift tfCl □ JIM C —] [■=

C-=-3 C-=-] m“ I ШШ HUU

F A X N o , 3 1 7 2 4 0 5 6 6 2 P . 0 0 9

W2-E JUMPER 3RD STAGE

W2-W3 JUMPER 2ND STAGE

XPOfiM

^6-IN, MALE

EASTON

AMP-TYP

(£1) PLCS

«ОГОЯ

VAC •

t#-I

24D

VAC

240 1

TÎ ^

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-OOOC-

Irr-n--□--П-d

electric heaters are energized, the ICM3 will run the higher or heat pump efficiency airflow and electric heater airflow. The factory selection is largest heater range approved. (See Fig- 6-)

Fig, 6—Easy

B. AC/HP Size

The fectory 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. 6.)

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, (Sec Fig, 6.)

D. AC/HP CFM Adjust

Select low, medium, or high airflow. To provide any of these airflows, AC/HP ADJUST select must be moved to MED position. The factory selection is LO. The adjust selections HI/TO will regulate airflow supplied for all operational modes, except nonheat pump heating modes, +10 percent and -10 percent respec tively. The adjust selection options are provided to adjust airflow Supplied to meet individual installation needs for such things as noise, comfort, and humidity removal. (Sec Fig, ti,)

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. 6.) The selection options arc:

JEA1S1

П П П П T-1

i '''

\ To,

CES0130007-QI1

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

Select Board

V. TROUBLESHOOTING PCB

Use Fig. 7 and S and Tables 3,4, and 5 as guides in troubleshoot ing PCB unless otherwise noted.

A. If Fan Wilt Not Turn On Ftom Thermostat:

IF THERE IS NO HIGH VOLTAGE TO PCB:

IF PCB HAS HIGH voltage APPLIED TO IT:

.9-

1/4-in. male

FASTON AMP-TYP (9) PLCS

ASdOT6

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

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

3. A 30 sec on/90 see 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/lfiO sec off delay at half airflow, adding comfort‘and efficiency.

1. Check connection of 12-pin plug from heaters to receptacle

On Easy Select board. This supplies power to PCB- Be Smre

plug is connected properly,

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

plug and to sequencer number 1.

3. Check power leads LI and L2, If these arc not receiving

power. System cannot function.

1, Check low-voltage transformer leads (red and brown). Be

sure they are wired to correct locations, (Sec Fig. 6 and 8,)

A U G / 1 4 / 2 0 0 8 / T H U 0 3 : 4 7 P M

UTC TECH PUB

F A X N o , 3 1 7 2 4 0 5 6 6 2

P . 0 1 0

2, Check output voltage of transformer secondary side SEC2

and SECl. Be sure transformer output is around 24 vac. If tráíisfoTOjef output is zero vac and transformer is! receiving correct input voltage (208v or 240v), then transformer needs to be replaced with recommended transformer. If transfoirtier output is 24 vaCj proceed to items 3 and 4,

3. Check Jow-voltage fuse shown in Fig. 6. If fuse is blown, replace it. The transfortner cannot supply power to board with fuse blown or loose. 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 maximui» load on transformer is 40 va. If load on

transformer is excessive, the low-voltage 5-amp firse will blow to protect transfomicr. 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 miswirsd, fuse

may blow, if a heater is mis wired, correct miswiring.

4. Check Tl, 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 is not putting Out correct secondary voltage, transformer

needs to be replaced,

B, If Electric Heat Stages Will Not Turn On But Fan WIN

Turn On:

1. Check wiring of sequencers. Pay particular attention to high- and low-voltagB 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, cheek to see if sequencer is closing. If sequencer is not dosing but is

10-

A U G / 1 4 / 2 0 0 8 / T H U 0 3 : 4 7

SIZE FEMALE

0.250 X 0.032

0.187 X 0.032

TABLE 4™C0NNECTI0NS ON SINGLE BARRIER StrIR MOUNTED, CROSS SLOTTED, CAPTIVE BINDING HEAD

SCREW

TERMINAL

Y/Y2 Connection for Y signal from thermostat

G 0

R C

UTC TECH PUB

F A X N o , 3 1 7 2 4 0 5 6 6 2

0 1

TABLE 3—MALE/FEMALE QUICK-CONNECT TERMINALS

SIZE MALE

M2 Motor line voltage connection (230 vac 60 Hz) T3

T2 SEC1 SEC2

HUM1 HUM2 AUX1

AUX2

REd I

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

Connection for G signal from thermostat Connection for 0 signal from thermostat

This connection Is a field termination for use in connecting L lines of thermostat and outdoor unit together. Thare is no connection of this terminal with control circuity.

Connaction for low-speed compressor operation Connection for R signal to tharmostat (24 vac) Connection for C terminal to thermostat (24 vac common)

Transformer line voltage connection (230 vac go Hz) Transfomior tap storage terminal for 208-vac lead Secondary connection from transformer (24 vac)

This connection is common to chassis ground through sydet marked GROUND SCREW REQUIRED, Secondary connection from transformer (24 vac) Low voltage ground for humidifier option (24 vdc) Low voltage output for humidifier option (24 vdc) Low voltage ground for auxiliary option (24 vdc)

Low voltage output for auxiliary option (24 vdc) Common connection to blower motor Common connection for transformer Common to R screw terminal and SEC2

DESCRIPTION

TABLE 5—CONNECTIONS AND CONNECTOR

TYPE

CONNECTION

Heater

Connection

ICM2 Motor

TYPE

CONNECTOR

12-Pln

7-Pin Header

PIN NO.

Pin 1 Common to E screw terminal Pin 2

Pin 3

Pin 4 Common to C screw terminal, SEC1 terminal, and chassis ground

Pins

Pin 6

Pin? Plh'B Pin 9

Pin 10

Pin 11

Pin 12

Pin 1 Pin 2

Pin3

Pin 4

Pins

Pin 6 Pin?

receiving correct voltage, replace sequencer. If sequencer is dosing, check high-voltage wiring as discussed in items 1 and 2.

IF THERE ARE BLOWN DIODES:

If diodes are blown, it is probable electric heater plug is miswired. Correct miswiring.

NOTE: Board will need to be replaced if diode is bad.

DESCRIPTION

Common to W2 screw terminal Common to C screw terminal, SEC1 terminal, and chassis ground

No connection Common to W3 scraw terminal

Common to M2 and T3 quick-connects, 230 vac input No connection

Common to Mi and T1 quick-connects, 230 vac input

No connection No connection No connection Diode OR output of E or W3 or W2 thermostat signals Thermostat G signal Common to C, SECI, and chassis ground Common to C, SEC1, and chassis ground Common to R and SEC2 (via 5-amp fuse)

Thermostat Yrir2 signal Thermostat Y1 signal

IF TRACES ARE OVERHEATED ON BACK OF PQB;

Usually whenever there js a trace blown on PCB, it means cither 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 PCB has power applied to it.

-11-

AÏÏG/14/2008/THÏÏ 03:47 PM UTC TECH PUB

FAX No. 317 240 5662

P. 012

-H !

■mis COMPARTMENT must be closed except for servicing

&DKW IPH SCHEMATIC PI AG RA^O

FIELi] WIFtlrJÜ

PH ■ Л __j_ Lam

PLUE 1 ПЁЬ

DISCONNECT PER NEC

____

_____

üSâ rtAïiNiï plate

_ j.

PLUlj Я

CAUTION:

exceeding 150V to ground

ATTENTION:

DE PLUS DE 150 V A LA TERRE

QlfiCONHECT PER NEC

|oND I

FIELD POWER WIRING

SEE RATIHQ PLATE

pgn VÛLT3 t HERTZ

hfOT SUITABLE FOR USE OW SYSTEMS

NE CONVIENT FAS AUX INSTALLATIONS

fjliHEMATia OlAflftAM

[5E5 NPT41)

( cot^jjHceoNTBQL wifliHa 1

COQLINa CONTROL ONLY

-----------

VIÜ

AUX HEAT RANGE

4-0 о ,o О

ACЛ^P SIÎR

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BLU

ПА 1И

—О © © ©“

QRY

red

RED

BLK

—®

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AJ HP-COMFORT HP-CFF g]—

О о

... . HCIHP CFM TRIM

АС/HP DELAY OW/OFF

Oran ЗПРГ1г 30Î3D □/□

О О О О

йЁса^Х^

_______

5ЯС1 *=* AUX1 HUM1

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----------

INDOOR THERMOBTAT

.я,о^ РСВ

NOTEfi:

11 U80 copper Wire only between dleconnect ewHoh unit.

2. Connect (Y) to fV), (C) to (C), fito. In pattern etiown.

a. Tmnaformer primary leads; BLUE MflV, RED 230V.

4. To be wired in Bccordendo^ with NEC and Id cal cOdea. 5, It any of the ortalnal wire, ав supplied, must b? roplaned, use the same Or“

G. Replace low voltage fuse with no greater than 5 emp tose,

7, Fuse is wired In series between transformer' SEC2 end lOW VOllsge 'Ft' circuit,

8. BOKW heator ubbb one double pole LS on middle top elertient.

9.16,24 and 30Kvy heaters use double pole limit swibhes.

ID. Largest heatera are shown, smaller heaters will have tawar elamanta and

□□mporients.

11,1 phase heaters are shown wired for single supply circuit. Multiple

supply clrculte may be wired directly to fuse/C.B.'S.

Fig. 8—FK4B Wiring Diagram

equivalent type wire.

-12^

Oy^L I Y". .

ЮфффффШф

blkT вшТоенТа^

HARKED TERMINAL

UNMARKED TERMINAL

FIELD POWER WIRING

----Й----

PLUG AND RECEPTACLE PCB BREAKOFF JUMPER

AUX

auxiliary

PRINTED CIRCUIT BOARD

PCB НРТВ

HEAT PUMP TERM BRD LOW VOLT TERM BRD

LVTB

SEQUENCER

8ЕС1 HTR

HEATER

HIGH VOLTAGE TERMINAL BOX

HVTB ним

HUMIDIFIER

- LEGEND

LIMIT SWITCH

LS ICM FAN MOTOR TRAN TRANSFORMER GND

EQUIPMENT GROUND

FU FUSE

RECEPTACLE

RECP CB CIRCUIT BREAKER F

LOW VOLTAGE FUSS

320486-301 REV. C

A94078

AUG/14/2008/THU 03:48 PM UTC TECH PUB

FAX No. 317 240 5662

TABLE e—МОТОВ CONTROL TEST VALUES

OPERATING MODE

Electric

1-Speed A/C

2-Speed A/C, Low Speed

S-Speed A/C, High Speed

1-Speed HP

1-Speed HP 2-Speed HP, Lew Speed Cooling R 2-5peed HP, Low Speed

2-Speed HP, High Speed

ContinuDue Fan

Pin 1 @ 24 vdc with or without jumpers when ever any Individual heeter input or any combination of heater inputs are energized.

Heating R Cooling R

Cooling R

Heating R

Heating Cooling R

Heating R

SCREW TERMINALS

HAVING 24 VAC

W2 W3* E*

Y/Y2

Y1 Q Y/Y2 G Y/Y2 G 0

Y/Y2 G

Y1 G 0

Yi G

Y/Y2 Y/Y2 YI Q

Y1 G

Pin 1

24 vde

0 £4 vac 0 □ 0 0 0 24 vac 0

0 0

VOLTAGES—7-PIN PLUG P2

Pin 2CPln3

£4 vac , 0

24 vac 0 £4 vac 24 vac £4 vac 0

24 vac 0 24 vac 24 vac 0

Pin 4RPin 5

□ 0 £4 vac 0

□ 0 24 vac

0 £4 vac

24 vec

0 24 vac

24 vac

0 0 24 vac

£4 vac

24 vac 24 vac 24 vac

24 vac

P. 013

Y/Y2 Pin 6

24 vac 0

0 24 vac 0 24 vac 24 vac 0

0 0

24 vac

Q 0

Pin 7

24 vac

24 vac 24 vac

24 vac

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 fransforaier, 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 levy-voltage signals,

1. Check transformer and thermostat wiring. (See Fig. 6 and 8,) Be Sure transformer is not shorting out because thermo stat wires are miswired,

2. Check wiring of sequencers. (See Fig. 6 and 8,) Be sure low-voltage and high-voltage wiring are connected to proper sequencers.

3. Check va draw o.n 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,

VI. TROUBLESHOOTING ICM2 FAN MOTOR A. If Motor Does Not Run:

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

%. Verify that there are approximately 230v at terminals Ml

apd Iyf2.,lf not, determine if high voltage is entering board. It enters through black and yellow wires at pins 7 and ? in 12-pin plug.

3, Verify that there is a low-voltage control signal to motor.

The motor receives its contml signals through the 7-pin mQ,tor plug P2. The voltage output of each pin in plug will be different for each mode of operation. Table 6 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-balapce 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 ICM, the shaft does not rotate

smoothly. The shaft has steps during rotation and is 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 nin, remove all thermostat wires. If motor stops, replace circuit board.

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

VII. CONDENSED VERSION OF TROUBLESHOOTING FK4B MOTOR AND CONTROLS

This section provides a quick summary of how to troubleshoot the FK4B. If more information is needed, refer to appropriate sections

of this service manual.

+ MOTOR

- If motor is hard to turn manually, replace motor.

- If motor docs 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 below.

- 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,''it is either the circuit board or thermo stat 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 Ml and M2. If m voltage is present, check power to'board. 230-v power enters the board through the black and yellow lead in the 12-pin plug,

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

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

'13-

A Ï Ï G / 1 4 / 2 0 0 8 / T H U 0 3 : 4 8

+ ROOM THERMOSTAT

- Remove thetrtiOStst 'wires from the circuit board,

- Jumper screw terminais (J at & time) R-G, R-Y/Y2, R-YJ^ and R-W2, If motor runs in all cases, thermostat is bad. Replace thermostat. 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.

CAUTION: 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. Check for 24v between pin-1 and pin-12 on the l6-pin plug.

If rm voltage is present, replace wiring'harness. (See Fig, 9.) If voltage is present, jumper screw terminal R-Y/Y2 on

circuit board and check for 24v between pjh-1-2 and pin-14 on 16-pin plug. (See Fig. 9 ) If no voltage is present, replace harness.

H 24v is present, the motor is bad. Replace motor.

UTC TECH PUB

F A X N o , 3 1 7 2 4 0 5 6 6 2

0 1 4

16 15 14 13 12 11 10 9

8 7

ЗИШИ1

Fig. Э—Wiring Harness 16-Ptn Plug VIII. ACCESSORIES A. Electronic Air Cleaner (EAC)

Familiar 230-vac EAC control/power signal EACl and БАС2 is not available, because the ICM2 blower motor used in the FK4B Fan Coil is controlled by low-voUsgc signals. This signal is replaced by a 24“Vdc signal which is provided at circuit board terminals AUXl and AUX2, (See Fig 6.)

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, KFAJROIOIACR, 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 arc present. (See Fig. 10 and 11.)

In heat pump applications, the G signal is present in both cooling and heating modes, permitting НАС 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-Hufflidify Mode NOTE: Humidistat must open cm humidity rise.

Latent capacities for systems using the FK4B Fan Coil are better

than average systems. If increased latent capacity is an application requirenjeut, the FK4B can be wired to provide this requirement by adjusting its airflow in response to standard humidistat input. Fig. 12 illustrates the wiring connections to activate de-huraidify mode. Carefully consult product airflow data for cooling and dehumidiiying mode,

THERMOSTATIC EXPANSION VALVES (TXV)

The FC4B and FK4B Fan Coils are factory equipped with a hard shutoff (HSO) TXV,

5 4 3 2 1

16-PIN PLUG

A94375

A9321S

Fig. 10—Mounting KFAIRO101ACR Relay Kit

FK4B

AUXl AUX2

Fig. 11—KFAlROlOIACR Relay Kit Wiring

RED WIRE ГЛ

FROM ЮМ2 -f-i-

MOTÛR

Fig. l3“HumIdIstat Wiring for De-Humidify Mode

The hard shutoff TXV has no bleed port and allows no bleed-

through after system is shutdown. No pressure equalization occurs. A start capacitor and relay must be installed on single-phaSc reciprocating compressors to boost torque to compressor motor so it may overcome the unequalized system pressures.

110 VAC BRANCH CKT

GND HOTNËUT

Schematic

HUMIDISTAT

HUMIDISTAT wiring FOR DE-HUMlDiFY MODE

TO PCB TERMINAL

MARKED 'RED'

A93215

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A D G / 1 4 / 2 0 0 8 / T H U 0 3 :

UTC TECH PUB

F A X N o , 3 1 7 2 4 0 5 6 6 2

P , 0 1 5

The standard TXV is a bi-flow meterijig device that is used in

condensing and heat pump systems to adjust to changing load conditions by maintaining a preset superheat temperature at outlet of evaporator coil. The volume of refrigerant metered through valve scat is dependent upon the following:

1. Superheat temperature sensed by sensing bulb on suction tube at Outlet of evaporator coil. As long as this bulb contains some liquid refrigerantj this temperature is con verted into pressure pushing downward on the diaphragm, which opens the valve via push rods,

2. The Suction pressure at outlet of evaporator coil is trans ferred via the external equalizer tube to underside of diaphragm.

3. The needle valve On pin carrier is spring-loaded, which also exerts pressure on underside of diaphragm via push rods,

which doses valve. Therefore, bulb pressure equals evapo rator pressure at outlet of coil plus spring pressure. If load increases, temperature increases at bulb, which increases pressure on topside of diaphragm, which pushes pin carrier

away from seal, opening valve and increasing flow of re:frigerant. The increased refrigerant flow causes increased leaving evaporator pressure which is transferred via the

equalizer tube to underside of diaphragm, with which the pin carrier spring pressure closes valve. The refrigerant flow is effectively stabilised to load demand with negligible change in superheat.

The bi-flow TXV is used on split system heat pumps. In cooling mode, TXV operates the same as a standard TXV previously explained. However, when system is switched to heating mode of operation, refrigerant ,flow is reversed. The bi"flow TXV has an

additional internal cheeje valve and external tubing. These addi tions allow refrigerant to bypass TXV when refrigerant flow is reversed with only a 1- to 2-psig pressure drop through device. When heat pump switches to defiost mode, refrigerant flows through a completely open (not throttled) TXV, The bulb Senses the residual heat of outlet tube of coil that had been operating in heating mode (about S5“F and 155 psig). This temporary, not throttled valve, decreases indoor pressure drop, which in turn .

increases refrigerant flow rate, decreases overall defrost time, and enhances defrost efficiency.

I. PROBLEMS AFFECTING TXV

A. Low Suction Pressure

1. Restriction in TXV

2. Low refrigerant charge

3. Low indoor load

4. Low evaporator airflow

B. High Suction Pressure

1. Overcharging 2, Sensing bulb not secure to vapor tube 3, High indoor load

4. Large evaporator face area

When installing or removing TXV, wrap TXV with a wet cloth. When reattaching TXV, make sure sensing bulb is in good thermal contact with suction tube.

PISTON BODY CLEANING OR REPLACEMENT

CAUTION; Do not vent refrigerant to atmosphere. Re^

cover during system repair or final unit disposal.

CAUTION: Damage may occur to the scroll compressor

A if operated at a negative suction pressure during a system

pumpdown.

1. Pump down outdoor unit. Close service valves at outdoor unit.

2. Recover remaining refrigerant from tubing and coil through gage port On vapor-tube service valve.

3. Disconnect refrigerant (liquid) tube from piston body, (See Fig. 13.)

4. Avoid damaging seal ring or machined surfaces on piston,

bore, and retainer.

5. Using small wire with a hook on end of it, remove piston from body.

A93530

Fig. 13—Refrigerant Flow-Control Device

(For FA, FB, and FF)

CAUTION: When cleaning the pi?ton orifice, be careful

not to scratch or enlarge the opening, as this will affect

operation.

6. Install new or cleaned piston into body.

7. Replace seal ring on retainer.

S. Reconnect refrigerant tube to piston body,

9. Pressurize tubing and coil, then leak check.

10. Evacuate tubing and, coil as necessary.

CAUTION: Use a backup wrench and do not over

tighten, as deformation of the piston body will occur,

Causing the piston to lodge in a partially open or closed

position.

LIQUID TUBE STRAINER

The TXV and refrigerant flow-control device is protected on the indoor coil by a wire mesh strainer. It is located inside the 3/S-in. liquid tube at field braze joint just outside unit casing. Access to

strainer is through field braze joint.

COIUCONDENSATE PAN REMOVAL

I. A-COIL UNITS

If it is determined that system does not have leaks and refiigerant

is not contaminated, proceed as follows:

1, Recover system refrigerant.

AND replacement

^15-

A U G / 1 4 / 2 0 0 8 / T H U 0 3 : 4 8

Fig. l4"’A-Coil Component Lpç^tion

a. Attach jïiajiifüld/gage sfit to scrvict valves. b. Front seat (dose) liquid tube service valve. c. Start unit in cooling mode. d. Run unit until vapor pressure reaches 5 psig (35kPa). e. Turn off electrical supply to outdoor unit.

£ Front seat vapor service valve. g, Recover any remalning .refrigerant.

NOTE: All outdoor unit coils will hold only factory-supplied amount of refrigerant. Excess refrigerant;, such as in long-tube applications, may cause compressor internal pressure relief valve

to open (indicated by sudden rise in vapor pressure) before vapor pressure reaches 5 psig C35kPa), If this occurs, tiim riff electrical supply to outdoor unit immediately, front seat vapor service valve, and recover any remaining refrigerant,

2. Turn off electrical supply to indoor unit.

3. Disconnect condensate drain tube,

4. Disconnect liquid and vapor tubes from indoor coil. Use a tubing cutter to cut tubes.

NOTE; If a torch is used to unbrace tube set, protect fitting panel with a wet cloth or braze shield, as necessary.

5. Remove coil access panel,

6. Remove clip securing fitting panel to condensate drain pan. Remove fitting panel,

7. Remove any shipping dips, including horizontal pan clip, and slide coil/condcnsatc pan assembly out of unit.

8. Upflow or Horizontal Applications Only—Remove hori zontal condensate drain pan from coij/condensate pan assembly. (See Fig. 14.)

UTC TECH PUB

A902G8

F A X N o , 3 1 7 2 4 0 5 6 6 2

9- Remove 4 coil brackets. (See Fig. 14.)

10. Remove screws at delta plates and remove coil from vertical condensate drain pan, (Sec Fig, 14,)

11. Horizontal Applications Only—Remove coil top seal

(attached with, 4 screws) and J-shaped tube from original

coil and install it in same position on new coil. (See Fig,

14.)

12. Place coil assembly in plastic condensate pan and secure using 4 screws through delta plate, (See Fig- ,14.)

13. Horizontal andUpflow Applications Only—Attach 4 coil brackets to coil/pan assembly. (See Fig. 14.)

14. Horizontal Applications only—Place horizontal conden

sate pan into position on coil/pan assembly,

NOTE: Installation of horizontal cemdenfiate pan is not necessary for upflow or downflow applications,

15. Slide complete assembly into unit,

16. Reinstall fitting panel and reconnect clip securing fitting pane] to condensate drain pan.

17. Horizontal Applleotions Only — Reinstall horizontal pan clip. Secure with 1 screw. (See Fig. 14.)

18. Reinstall coil access panel.

19. Reconnect liquid and vapor refrigerant tubes, and conden sate drain tube. Install Elter-drjer(s), if necessary.

20. Eyhcu^ate tube set and indoor coil, back seat (open) liquid and vapor service valves.

21. Turn'bn electrical supplies to indoor and outdoor units.

22. Check system refrigerant charge and operation. See "Split-

System Residential Air Conditioners and Heat Pumps Service Manual" for further information,

II. SLOPE COIL UNITS .

If it is determined that system does not have leaks and refrigerant is not contaminated, proceed as follows:

1. Recover system refrigerant.

16-

AÏÏG/14/2008/THÏÏ 03:49 PM UTC TECH PUB

FAX No. 317 240 5662

P. 017

a. Attach manifold/gage set to service valves, b. Front scat (close) liquid tube service valve, c. Start yirit in cooling mode. d. Run unit until vapor pressure reaches 5 pSig (35kPa).

c. Turn off electrical supply to outdoor unit. f. Front seat vapor Service valve. g. Recover any remaining refrigerant.

NOTE: All outdoor unit coils will hold only factory-supplied amount of refrigerant. E?tcess refrigerant, such as in long-tube applications, may cause compressor internal pressure relief valve

to open (indicated by sudden rise in vapor pressure) before vapor pressure reaches 5 psig (35Ji:Pa). If this occurs, turn off electrical supply to outdoor unit immediately, front seat vapor service valve, and recover any remaining refrigerant.

2. Turn off electrical supply to indpor unit.

3. Disconnect condensate drain tube,

4. Disconnect liquid and vapor tubes from indoor coil. Use either a tubing cutter to cut tubes or a torch to unbrace tubes as required.

NOTE: If a torch Is used to unbraze line set, protect fitting panel

with a wet doth or br^e shield, as necessary. System contains oil

vapors which may ignite when ejeposed to a flame.

5. Remove coil access and fitting panels.

6. Remove 1 screw securing coil to unit casing.

7. Remove coil/pan assembly from unit.

8. Place assembly oti; a flat surface. Removc=2 screws securing coil support columns to pan. (See Fig. 15.)

9. Rotate columns 90“, pull away from coil, and remove columns from assembly.

10. Remove remaining 2 screws securing coil to condensate pan,

11. Remove coil from condensate pan.

12. Remove coil top seal, (See Fig. 15.)

.13. Install new coil into condensate pan using 2 original screws

and 2 support columns.

NOTE: Correct coil position in condensate pan is essential to

reliable operation.

14. Install new coil/pan assembly into unit. Secure with 2 Sci:c'vv5 previously removed from unit casing,

15. Reinstall coil access and fitting panels.

16. Reconnect liquid and vapor refrigerant tubes, and conden sate drain tiibe. Install fr]t6r-drier(s), if necessary.

17. Evacuate tube set and indoor coil, back scat (open) liquid and vapor service valves.

18. Turn on electrical supplies to indoor and outdoor units.

19- Check system refrigerant charge and operation. See ''Split-

System Residential Air^Gonditioners and Heat-Tumps Service Manual" for further information.

WARNING; Disconnect all power to the unit before

servicing the field wires Or removing the control package. The disconnect (when used) on the access panel does not

disconnect power to the line side of the disconnect, but does allow safe service to all other parts of the unit.

Electrical shock can cause personal injury or death.

The minimum maintenance requirements for this equipment are as

follows:

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

2. Inspect cooling coil, drain pan, and condensate drain each cooling season for cleanliness. Clean as necessary. An inspection port is provided on all A-coil delta plates. Remove plastic plug to inspect. Replace plug after inspec tion.

3. Inspect blower motor and wheel for cleanliness each

heating and cooling season. Clean as necessary.

4. Inspect electrical connections for tightness and controls for proper operation each heating and cooling season. Service as necessary.

WARNING: As witja^any mechanical equipment, per

sonal injury can .result frpm sharp metal edges. Be careful

^vyhen, removing,parts.

I. FILTER ASSEMBLY

To clean Or replace air filter, push plastic connectors toward center

of unit and remove filter access panel outward. -Push filter up and back into unit. Then slide filter out. Clean filter by tising cold water and mild detergent. Rinse and allow filter to dry. No oiling or coating of filter is required. New filters are available from your local distributor. Place filter in slot with cross-mesh binding up or

facing cooling coil and replace filter access panel,

II. COOLING COIL, DRAIN RAN, AND CONDENSATE DRAIN

The cooling coil is easily cleaned when it is dry. Inspect the coil and clean (if necessary) before each cooling season. To check or clean cooling coil, rethov^ coil access paiidl. If coil is coated with dirt or lint, vacuurn it' with a soft brush attachment.

Be careful not to bend coil fins. If coil is coated with oil or grease,

clean it with a mild detergent and water solution. Rinse coil thoroughly with olpar water;^Be careful not,to splash water on insulation,

Inspect drain pan and condensate drain at the same time cooling coil is checked. Clean drain pan and condensate drain by removing any foreign matter fitom pan. Flush pan and drain tube with clear

water. If drain tube is restricted, it can generally be cleared by high-

pr'essure water. Cut plastic line and, work outside condensate pan and away from coil to clpan drain tube, ,,

CARE AND MAINTENANCE

To continue high performance, and minimize possible equipment failure, it is essential periodic maintenance be performed on this equipment,

11)6 ability to properly perform maiuteuauce on this equipment requires certain mechanical skills and tools- The only consumer service recommended or required is filter maintenance. (See Filter Assembly.)

-17-

CAUTION: Dp not use caustic household drain cleaners

in the condensate pan or near the coil. Drain cleaners can quickly destroy a coil,'

III. BLOWER MOTOR AND WHEEL

Clean blower motor and wheel when cooling coil is cleaned.

A U G / 1 4 / 2 0 0 8 / T H U 0 3 : 4 9

UTC TECH PUB

1 , 3 1 7 2 4 0 5 6 6 2

P , 0 1 8

CAUTION: Disconnect elfictdcd power before remov-

Щ any access panels.

To clean blower motor or blower wheel:

1. Remove blower access panel.

2. Remove motor leads from PCB. Note lead loofttion for case of reassembly.

3. Remove 2 outside screws holding blower/jiiotor assembly against blower-deck flange and slide assembly out of cabinet,

4. Remove screw in strap holding motor capacitor to blower

housing and slide capacitor Out from under strap. Remove screw with green wire from blower housing. Mafic blower wheelj motor, and motor support in relation to blower housing before disassembly to ensure proper reassembly.

Note position of blades on wheel,

5. Loosen setscrew holding blower wheel onto motor shaft,

6. Remove 3 bolts holding motor mount to blower housing and

slide motor and mount out of housing. Further disassembly should not be necessary as adequate clearance is available.

7. Remove blower wheel from housing by removing cutoff plate from blower housing outlet. Note wheel orientation and cutoff location for reassembly. The blower motor and wheel may be cleaned by using a vacuum With a soft-brush attachment.

S. Remove grease with a mild solvent such as hot water and

detergent. Be careful not to disturb balance weights (clips)

on blower-wheel vanes. Also, do not drop or bend wheel, as balance will be affected.

To reassemble blower:

f. Place blower wheel back into housing. Be sure to position

correctly for proper location.

2. Reassemble cutoff plate to housing using identified holes disassembly procedure.

3. Position motor and mount in same position as when blower

housing was in unit. Secure motor mount on housing, using removed bolts. Make sure mount or motor is grounded to. blower hoiising.

4. Locate blower wheel setscrew over flat on motor shaft.

Rotate wheel in housing. It should not mb housing and

should be centered in inlet opening. If notj loosen setscrew

and align as necessary.

5. Attach green wire to blower housing with screw.

6. Secure motor capacitor under strap and tighten strap screw.

7. Slide blower assembly to blower deck. Be sure (once blower is within the unit casing) to force blower assembly toward control box while sliding assembly into unit to ensure that blower assembly engages deck properly.

8. Fasten blower assembly to deck with screws previously removed.

9. Reconnect electrical leads to PCB.

10. Reconnect electrical power to unit and test fan for proper rotation.

FF1A/FF1B SERVICE AND TROUBLESHOOTING

WARNING: Before installation or servicing system, always turn off main power to system: There may be more than 1 disconnect switch. Turn off accessory heater power if applicable. Electrical shock can cause personal injury or death.

L FAN MOTOR

The motor is 2-spccd direct drive. High-speed lead is black, low-speed lead is red, and common lead is violet. Be sure proper blower speed has Ьeí^п selected. For units with electrical heat, low-speed tap can be used. For cooling, use high-speed tap.

The motor is turned on through 2 different routes. The first occurs when thermostat calls for the fan in cooling, heat pump, or fan-only mode, A 24-vac signal is sent to relay, causing relay to dose its normally-open contacts, turning fan on. The second occurs when there is a call for electric heat. A 24-vac signal is sent to heater sequencer, causing it to dose, directing 230v through the normally-closed contact of fan relay, turning fan on. The fan remains on until sequencer opens. Refer to FFIA/FFIB typical

wiring diagram Shown in Fig. 16. If motor docs ПШ, test motor for an open winding or a winding

shorted to motor case. If any 1 of the 2 is present, replace motor.

II. ELECTRIC HEATER SERVICE

Service can be completed with heater in place. Shut off power

before servicing,

A. Limit Switch

Malfunction prevenís heating element from coming on. Replace switch if malfunction occurs.

B. Sequencer

Malfunction causes heater not to come on or never shut off.

Replace sequencer. '

C. Transformer

A 40-va transformer supplies 24-v power for control circuit. Replace transformer if faulty,

NOTE: Transformer is fused. Do not short circuit. D. Fan Relay

Malfunction causes unit fan not to run Or run continuously. Replace relay.

III. CLEANING OR REPLACING REFRIGERANT FLOWCONTROL DEVICE

Refer to Fig. 13 and instructions given in Piston Body Cleaning or

Replacement section above,

IV. LIQUID TUBE STRAINER

The refrigerant flow-control device is protected by a wire mesh strainer. It is located inside the З/8-Ín. liquid tube at field braze

joint next to flow-control device. Access to strainer is through field

braze joint.

V. SEQUENCE OF OPERATION

Refer to Fig, 16,

A. Condensing Unit

COOLING

When thermostat calls for cooling, the circuit between R and G is complete and single-pole single-throw relay FR is energized. The nomially-open contacts close causing blower to operate. The circuit between R and Y is also complete. This completed circuit causes contactor in outdoor unit to close which starts compressor and outdoor fan.

-18^

AÜG/14/2008/THD 03:49 PM UTC TECH PUB

FAX No. 317 240 5662

P.019

SCHEMATIC DIAGRAM FOR 2. 9. & 5 KW HEATERS

SEE RATING PLATE

POR VOLTS & HZ

FIELD

POWER

SUPPLY

chassis'''^ Rp

GROUND TRANS

^V!0—

-r^GPN <:(FyG^ BRN

----

I,-----

_____

.SCHEMATIC DIAGRAM FOR 7.5 & 11 KW HEATERS

SEE RATING PLATE

FOR VOLTS Bl HZ

chassis“'^

GROUND

-[^ORN

SCHEMATIC DIAGRAM FOR COOLING CONTROL

SEE RATING PLATE

FOR VOLTS Si HZ

FIELD

POWER

-ORN

----------------

----

BLK

IFR fTDR OPTIONAL MOTOR CAP

BLK™(^ f^{^BLK

^ ' (^RED-

BLK slkKAVcpíO-^

SEQ ^LS

—BLK

IFR (TDR OPTIONAL) MOTOR CAP

BLK-(3)-|

BLK~—I HTR2

BLK^(^ f(^BLK-<AAX>2p—

■ SEQ - HTR1

SEQ ^LSI

RED |— BLU

OPTIONAL IFR/TDP

-BLK IFR [TDR OPTIONAL) MOTOR CAP

BLK©H f©)“BLK

©-RED,

a FR

OPTIONAL IFR/TDR

------------

(¿y^RED

Kiy-eLK-oWo^p—I

YEL

-----

I£1^YEL

^V)0-

-------------

-VlO

9^7^BRN2_

---------------

BLK-

CHASSIS

GROUND

COMPONENT ARRANGEMENT

TRANS I ÈAV

BLK 208 230

COM BLU RED

HTR2

DISCONNECT

WHEN EQUIPPED

MOTOR SPEED SÉLECTION

HI = BLACK LOW = RED COMMON = VlO

FIEl4D,W|RE

HEAT PKG.

2KW

3KW 5 KW 7,5 KW 11 KW 0 (COOLING)

FR IFR IFR/TD SEQ CAP HTR

TRANS

/7*7

UNIT WiRED-FQR 230V OPERATION USING BLACK AND RED TRANSFORMER PRIMARY

LEADS, FOR 2dSV OPERATION, USE BLACK

AND'BLUE TRANSFORMER-PRIMARY LEADS. UNUSED TRANSFORMER LEADS MUST BP TAPED

.AND1.QQPED,.

IF ANY OF THE ORIGINAL WIRE. AS SUPPLIED, MUST BE REPLACED, USE THE

SAME DR EQUIVALENT WIRE. FIELD WIRING. USE COPPER CONDUCTORS.

ONLY. FAN RELAY M IS A DEAD TERMINAL FOR

UNUSED MOTOR LEAD STORAGE. TO CHANGE MOTOR SPEEDS, EXCHANGE THE BLACK AND RED MOTOR LEADS ON THE FAN RELAY.

MARKED TERMINAL

UNMARKED TERMINAL LIMIT SWITCH FAN RELAY INDOOR FAN RELAY INDOOR FAN RELAY/TIME DELAY

SEQUENCER CAPACITOR HEATER TRANSFORMER ' FIELD POWER WIRING

OPTIONAL WIRING FUSE CHASSIS GROUND

SIZE

' ^4

. ID'

LEGEND

■ NOTES

TEMP.

RATING

90"C

90“C

go'C âü“c

30"C 90“C

316596-401 REV. B

FÎ0. 16—FF1A/FF1B Typical Unît Wiring Label

-19-

A9114Q

A U G / 1 4 / 2 0 0 8 / T H U 0 3 : 5 0

UTC TECH PUB

F A X N o , 3 1 7 2 4 0 5 6 6 2

P .

HEATING

When thermostat calls for heating and FAN switch is set on AUTO, the circuit between R and W is complete. The heater sequence SEQ is enfirgjitd which closes contacts of relay. There will be a time delay. This completed circuit enejgijes all heating elements HTR and blower motor.

B, Heat Pump COOLING

On a call for cooling, the thermostat makes circuits R-0, R-Y, and

R“Q. Circuit R-0 energizes reversing valve, switching it to cooling position. Circuit R-Y energizes contactor starting outdoor fan motor and compressor. Circuit R-G energizes indoor unit blower relay starting indoor blower motor. When thermostat is satisfied, its contacts open de-energizing contactor reversing valve and blower relay. This stops compressor and fan nibtofs.

HEATING

On a call for heating, the thonnostat makes circuits R-Y and R-G, Circuit R-Y energizes contactor starting outdoor fan motor and compressor. Circuit R-G energizes indoor blower relay starting

blower motor. Should temperature continue to faIl„R-W circuit is made through second-stage room thermostat bulb. Circuit R-W energizes a sequencer bringing on supplemental electric heat.

When thermostat is satisfied, its contacts open de-enftrgiiing

contactor and sequencer. All heaters and motors should stop.

VI. CARE AND MAINTENANCE

The minimum maintenance requirements for this equipment are as follows:

1. Inspect and clean or replace air Eltor each month or as required.

2. Inspect cooling coil, drain pan, and condensate drain each cooling season for cleanliness. Clean as necessary,

3. Inspect blower motor and wheel for cleanliness each heating and cooling season. Clean-as necessary,

4. Inspect electrical connections for tightness and controls for proper Operation each heating and cooling season. Service as necessary.

WARNING: As with any mechanical equipment, per

sonal injury can result fi:om sharp metal edges. Be careful when removing parts.

A. Air Filter

To clean or replace air filter, grasp it at bottom and lift it out of unit. Clean filter using cold water. Rinse clean and let dry. Oiling or coating of filter is not required. To replace, stand filter in rack with binding facing coil. Press top edge under access panel.

NOTE: Steel rods in filter prevent it from being pulled into coil.

Retain these rods and reinstall after cleaning or before replacement if new filter is used.

A CAUTION; Never operate unit without a filter.

B. Cooling Coil, Drain Pan, and Condensate Drain

The cooling coil is easily cleaned when it is dry. Inspect coil and clean (if necessary) before each cooling season. To check or clean

cooling coil, remove blowcr/hcatcr access panel to gain full access to cooling coil- If coil is coated with dirt or lint, vacuum with a soft brush attachment.

Be careful not to bend coil fins. If coil is coated with oil or grease, clean it with a mild detergent-and-water solution. Rinse coil with clear water. Be cajcfol not to splash water onto insulation.

Inspect drain pan and condensate drain at same time cooling coil is checked. Clean drain pan and condensate drain by removing any foreign matter from pan. Flush pan and drain tube with clear water.

If drain tube is restricted, it- can generally be cleared by highpressure water. Cut plastic line and work outside condensate pan

and away from coil to clear drain tube.

NOTE: There MUST be a trap in condensate line. Trap must be

at least 3-in. deep, not higher than the bottom of unit condensate drain opening, and pitched downward to an open drain or sump.

CAUTION: Do not use caustic household drain cleaners

in condensate pan or near coil. Drain cleaners can quickly

destroy coils.

C. Blower Motor and Wheel

Clean blower motor and'wheel when cooling coil is-cleaned.

To clean or service wheel or motor, proceed as follows:

1. Pull unit disconnect (when used) and remove blower access panel.

2. Disconnect motor electrical leads from control box and capacitor. Mark location of wires for reassembly.

3. Remove 3 bolts holding motor mount to blow'er bousing

while supporting motor shell with hand.

4. Pull motor inlet ring and blower wheel assembly out of blower housing.

5. With blower wheel, inlet ring, and motor mount still attached to motor, place motor on flat, horizontal surface,

shaft up, Mark position of wheel on motor shaft for reassembly.

6. Loosen blower wheel setscrew and remove blower wheel

from motor shaft.

NOTE: Further disassembly of motor and mount is not necessary

■ as adequate clearance is available to clean motor.

7. Qean blower motor and wheel using a vacuum with a soft

brush attachment- Remove grease with a mild solvent such as hot water and detergent. Be careful not to disturb balance weights (clips) on blower wheel vanes. Do not drop or bend wheel as balance will be affected.

To reassemble unit, proceed as follows;

1. Place motor with mount attached on flat, horizontal surface with shaft up-

2. Sef inlet ring 6n fop of motor mount grommets/ Center inlet ring flush on all 3 grommets.

3. Slide blower wheel onto motor shaft with setscrew upward and aligned with shaft flat portion. Vertically position wheel along shaft to position marked during disassembly.

NOTE: If previous shaft was not marked or if replacing previous motor, set blower wheel position by sliding blower wheel along motor shaft to 1-1/8 in, above rubber grommets. (See Fig, 17,)

4. Hold blower wheel in place and carefully tighten setscrew,

5. Position motor and blower wheel assembly to blower housing as originally oriented.

6. Secure motor mount to blower housing using bolts previ ously removed.

7. Attach green wire to blower housing with screw.

8. Connect electrical and capacitor leads to original terminals.

9. Replace blower access door and tighten all 4 screws,

10. Reinsert disconnect pullout only after blower access door is secured. Test blower for proper operution.

-20-

A U G / 1 4 / 2 0 0 8 / T H U 0 3 : 5 0

UTC TECH PUB

N o , 3 1 7 2 4 0 5 6 6 2

P . 0 2 1

BLOWER WHEEL

INLET RING

AÔËÛOS

FD3A SERVICE AND TROUBLESHOOTING

WARNING: Btfom instaJlation or servicing system,

always turn off main powet to system. There may be more than 1 disconnect switch/Turn off accessory beater power if applicable. Electrical shock can cause personal injury or death.

1. FAN MOTOR

The motor is 2-spccd direct drjve. High-speed lead is black, low-speed lead is red, and common lead is yellow,

NOTE: Unused fan speed leads must be tapped off to prevent

direct short to cabinet surface. The motor is turned on through 2 different routes. The first occurs

when thermostat calls for the fan in cooling, heat pump, or fan-only mode. A 24’Vac signal is sent to relay, causing relay to close its normally-open contacts, turning fan on. The second

occurs when there is a call for electric heat. A 24-vac signal is sent to heater sequencer, causing it to close, directing 230v through the normally-closed contact of fan relay, turning fan on- The fan remains on until sequencer opens. Refer to FD3A typical wiring diagram shown in Fig. 18.

li. ELECTRIC HEATER SERVICE

Service can be completed with heater in place. Shut off power before servidng-

A. Limit Switch

Malfunction prevents heating element from coming on. Replace

switch if malfunction occurs,

B. Sequencer

Malfunction causes heater not to come on or never shut off. Replace sequencer.

C. Transformer

A 60-va transformer supplies 24-v power for control circuit. Replace transformer if faulty.

NOTE: Transformer is fused. Do not short circuit.

D. Fan Beley

Malfunction causes unit fan not to run or run continuously. Replace relay.

E, Heater Removal

Disconnect wiring, remove 2 sheet metal screws, and pull heater out through Open hinged access panel. When replacing heater, ensure orientation of he&ter element is same as when removed.

ML cleaning OB REPLACING REFRIGERANT FLOW-

CONTROL DEVICE

1. Pump down outdoor unit. Close service valves at outdoor unit.

CAUTION: Damage may occur to the scroll compressor

if operated at a negative suction pressure during a system pumpdown.

2. Bleed and (if possible) recover remaining refrigerant from tubing and coil through gage port on vapor-tube service

valve.

3. Disconnect liquid refrigerant tube from refrigerant flow-

control device. Refer to Fig, 19,

4. Remove refrígerapt flow-control device piston retainer. Avoid damaging 6-xing or machined surfaces on piston, bore, and retainer,

5. Using small wire with a hook on end of it, remove piston

from refrigerant flow-control device body.

CAUTION: When cleaning piston orifice, be careful not

to scratch or enlarge opening as this will affect operation.

-21-

A U G / 1 4 / 2 0 0 8 / T H U 0 3 : 5 0

1-2

1-1

UTC TECH PUB

FIELD POWER SUPPLY

F A X N o , 3 1 7 2 4 0 5 6 6 2

SCHEMATIC DIAGRAM

P . 0 2 2

BLK—h5)-bLkAP[^

BLK^ SEQ ^

6LK—<2H

FH(3>—RED

N H

---------------

D E ! I

o M

---------------

R 0 I !

□RN

-----

L^h-

BRN

COMPONENT ARRANGEMENT

BED BRN

( IFM )- YEL r

------------

BLK -\ _ y—arm-?, 9 1^^ 9

/(OI=TIoWa1>,HTR-2 1 ft.3

SEQ /ipT'CJNAL>^HTB.1 ,g ,

_ r note #2

—VlO^LS-2

— TRANS

^^E_NqTE^^-^

-------

REm£pWE^WtplNG [y

- LEGEND -

““ FIELD POWER WIRING " - FIELD GROUND WIRING

-----

FIELD CONTROL WIRING

FIELD SPLICE

-•- JUNCTION

O MARKED CONNECTION

o UNMARKED CONNECTION FC FAN CAPACITOR FR FAN RELAY

HTR HEATER

IFM indoor fan motor

LS LIMIT SWITCH

QT QUAD terminal

SEQ SEQUENCER

TB TERMINAL BLOCK

TRANS TRANSFORMER

NOTES:

(OPTIONAL)

(fl

___

FUS!BLE_L1N1^^

----

WIRE SLEEVE

1. TRANSFORMER PIGTAILS: BLUE 20$V; RED 2ggV; INSULATE UNUSED LEAD.

2. FAN MOTOR pIGTaIls: RED LOW; BLACK HIGH, INSULATE UNUSED LEAD.

3. FAN MOTOR THERMALLY PROTECTED.

4. SUITABLE FOR USE WITH COPPER

OR COPPER CLAD ALUMINUM CONDUCTORS RATED FOR TS'-C MINIMUM. FOR COPPER USE 6

AWG. FOR COPPER CLAD

ALUMINUM USE 4 AWG,

40DQ500784 REV. C

Fig. 18—FD3A Typical Wiring Diagram

-72^

A94376

A U G / 1 4 / 2 0 0 8 / T H D 0 3 : 5 0

Fig, 19—Refrigerant Flow-Control Device

CAUTION: Use a backup wrench and do not over

tighten as deformation of refrigerant flow-control device

body will occur, causing piston to lodge in a partially

Open Or closed position.

6. Install new or cleaned piston in refrigerant flow-control device body.

7. Install new retainer (because of probable damage which occurred in initial remov&J)-

8. Reconnect refrigerant tube to refrigerant flow-cOntroI de vice.

9. Pressurize tubing and coil, then leak-check.

10. Evacuate tubing and cojl as necessary.

)V. LIQUID TUBE STRAINER

The refrigerant flow-coittrol device .is. protected on indoor coil by a wire mesh strainer. If strainer becomes plugged:

1. Complete items 1 and 2 under Cleaning or Replacing Refrigerant Flow-Control Device section.

2. Loosen flare fitting joint connecting refrigerant flowcontrol device to coil liquid refrigerant tube.

3. Remove sheet metal screw holding bracket clip in place, Screw is located between coil and refrigerant flow-control

device,

4. Pull bracket clip out.

5. Remove refrigerant flow-control device assembly,

6. Pull strainer out of coil liquid refrigerant tube and replace with new strainer,

V. CARE AND MAINTENANCE

WARNING: Hinged access panel contains electrical

components and is heavy. Support panel when lowering to clean unit to avoid personal injury.

WARNING: Disconnect electrical power to all circuits

before servicing unit. Failure to do so may result in personal injury from electrical shock ox movingiparts.

WARNING: As with any mechanical equipment, per

sonal injuXy can result from sharp metal edges. Be careful

when removing parts.

The minimum maintenance requirements for this equipment arc as

follows:

UTC TECH PUB

(For FD3A and FG3A)

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F A X N o . 3 1 7 2 4 0 5 6 6 2

1. Inspect and dean or replace field-supplied air filter each

month or as required.

2. Inspect cooling coil, drain pan, and condensate drain each cooling season for cleanliness. Clean as necessary. (To be performed by trained personnel.)

3. Inspect blower motor and wheel for cleanliness each heating and cooling season. Clean as necessary,

4. Inspect electrical connections for tightness and controls for proper operation each heating and cooling season. Service

as necessary,

NOTE: Never operate without a Alter or with hinged access door

Open, Damage to blower motor may result.

A. Cooling Coll, Drain Pan, and Condeneata Drain

Remember to disconnect electrical power before opening hinged access panel.

The cooling coil ig easily cleaned when dry. Inspect coil and clean (if necessary) before e&ch cooling season. If coil inlet face is coated with dirt or lint, vacuum with a soft brush attachment.

Be careful not to bend coil flns. If coil is coated with oil or grease,

clean it with a mild detergent-and-hot water solution. Rinse coil with olear water. Be careful not to splash water onto insulation.

Inspectidrain pan and condensate drain at same time cooling coil is checked. Clean drain pan and condensate drain by removing any foreign matter from pan. Fliish pan and drain tube with dear water. Clear drain line ifrresfricted.

NOTE: There MUST be a trap in condensate line. Trap must be

at least 3-in. deep, not higher than the bottom of unit condensate drain opening, and pitched downward to an open drain or sump.

B. Blower Motor and Wheel

Clean blower motor and wheel when cooling coil is deaned. Lubricate , motor every 5 years if motor is used on-intermittent opefafidn (thermostat FAN switch at AUTO position);, or every 2 years if motor is in continuous operation (thermostat FAN switch

at ON position). Remove motor to lubricate. Put approximately 8 drops of SÁE 10 nondetergent oil in each oil hole. Do not bveroil motor. Plug hole securely so that oil does not drip when hinged access panel is lowered'to 'open position.

Blower motor and wheel may be cleaned using a vacuum with a soft brush attachment. Remove grtaae with a mild solvent such as

hot water and detergent. Be careful not to disturb balance weights (dips) on blower wheel vanes. Do not drop or bend wheel as balance will be affeefed.

FG3A service and TROUBLESHOOTING

1. SERVICE

A. Motor ......................

Ball bearing oilers are provided on blower motor. Use electric motor oil 6r SAE lp or'20 nondetergent oil. Check motor mount

bracket and''Í3ás¿ bolte. Tighten as required.

B. Blower

Check ball bearings for wear. Ball bearings are self-aligning and

grease packed. Replace as required. Check thrust collars for end

play and alignment of wheel. Check blades for accumulation of.

dirt. Clean as required. Check mounting brackets, base bolts, and

isolation material. See Fig, 20 for diagram of internal wiring for blower coil

assembly. Control box (standard 4-in. junction box) is mounted on

refrigerant connection side of unit. All leads pass through strain relief where they enter Control box. Wiring inside cabinet is located so it does not come in contact with moving parts or sharp edges,

C. Pulley and Belts

Check beJt tension and pulley alignment. (See Fig, 21,) Belt tension is adjusted by motor tailpiece bolt, A deflection of about

3/4 in. to 1 in, per foot of span should be obtained by pressing belt

P . 0 2 3

A U G / 1 4 / 2 0 0 8 / T H U 0 3 : 5 1

UTC TECH PUB

F A X N o , 3 1 7 2 4 0 5 6 6 2

B. Coil, Drain Pan, and Condensate Drain

UNE

GROUNO LEAD

A91151

Fig. 20—Wiring Schematic

firmly. Lock adjusting bolt in position after adjustment is made. Align pulley grooves by locating motpr pujley on motor shaft or by moving entire motor along motor mounting bracket. Adjust blower speed by loosening setscrew in outer (moveable) pulley face and turning this face (half or full turns) so that adjusting setscrew is

positioned precisely over the flat on pulley hub. Speed is reduced by adjusting pulley faces so they are further apart; speeds is increased with faces closer together. Cheek pulley setscrews and bolts.

A91150

Fig. 21—Checking Pulley Alignment and Tightness

D. Cleaning or Replacing Refrigerant Flow-Control

Device

Refer to Fig. 19 and instructions given in FD3A Service and Troubleshooting section above,

II, MAINTENANCE

WARNING: Disconnect electrical power to all circuits

before servicing unit. Failure to do SO may result in

personal injury from dcctrical shock or moving parts.

WARNING: As with any mechamcaj equipment, per

sonal injury can result fi'om sharp metal edges. Be careful when removing parts.

A, Return-Air Filter

To clean or replace sir filter, remove screws and filter access door. Slide out filter. For washable type filters, clean with hot soapy

water. Rinse clean and let dry. New filters are available from a local distributor. Place filter in slot

with filter arrow facing direction of airflow. Replace filter access doors with screws previously removed.

CAUTION: Never operate unit without a filter or with

filter access door removed. Damage to blower motor may result-

CAUTION: Discounect electrical power before remov

ing any access panels or electrical shock may result.

The coil is easily cleaned when dry. To check or clean coil, remove coil access panel. If coil is coated with dirt or lint, vacuum with a soft brush attachment.

Be careful not to bend fins. If coil is coated with oil or grease, it may be cleaned with mild detergent and water solution. Rinse coil with dean water. Be carciiil not to splash water on insulation or filter.

Check drain pan and condensate.drain at same time cooling, coil is checked. Clean drain pan and condensate drain by removing any foreign matter from pan. Check for rust and holes. Flush pan and drain tube- with clear water. If drain is restricted, clean with high-pressure water. If this does not work. Use a plumbery's snake or similar probe device. Rcpitch drain pan to promote proper drainage.

FA4A, FB4A. AND FC4B SMART HEAT CIRCUIT BOARD

I. PCB COMPONENT LAYOUT, DESCRIPTION, AND FUNCTION

NOTE: All voltages are AC unless otherwise specified.

2. Jumper wires (JWl and JW2). (See Fig. 22.)

FUNCTION AND TROUBLESHOOTING

1. The low-voltage terminal board is used to coimeot indoor thermostat to low, 24-v side of transformer and to serve as a junction between indoor thermostat and outdoor seefion.

a, R terminal is used to connect secondary side of trans

former to thermostat and outdoor unit. R is fused.

b. C terminal is used to connect transformer secondary

common for thermostat and outdoor unit.

c, Y terminal provides input signal from thermostat signal

ing heat pump operation,

d. G terminal provitJes input signal from thermostat signal

ing cdnUiiiiOus fan 'dperatidn,

c, O terminal provides input and junction terminal for

reversing vaive sign'd.

f, W2D terminal provides input from outdoor unit (heat

pump) signaling control board that heat pump is in

defrost.

g. W2T terminal provides input from thermostat signaling

for supplemental or emergency heat.

h. W3 terminal provides input from outdoor thermostat.

W3 and W2T are factory connected by JWl. Thl^ input is used only if an outdoor thermostat is required by local

codes.

i, Y(, rerinihar provides output from control board to

energize outdoor unit (heat pump) contactor.

a. JWl connects W2T to W3 to limit staging of electric

heat with use of an outdoor thermostat. See Table 7 for staging. Smart Heat PCB controls staging to the extent that this feature is unnecessary unless required by local

codes Or regulations.

b. Cutting JW2 sets Smart Heat PCB in efficiency mods.

With JW2 cut, there is no loss of performance due to reduced indoor blower speed when heat pump is oper

ating near balance point. This jumper may need to be cut if selected cooling fan speed is the same as required minimum motor LO speed tap selection. With JW2 cut, fan terminal LO becomes a dummy terminal.

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F A X N o , 3 1 7 2 4 0 5 6 6 2

7 0 2 5

Fig. ;£2—Pi'inted-Cir'cuit Board (PCB)

3. A fuse is used to protect low-voltage transformer and PCB,

4. AUX+ and AUX- are connections for air.4 conditioning accessories (EAC, humidifier, etc.).

5- FI, F2, HI, and LO arc connections for indoor fan. 6, The 9-pin receptacle connects heater package wiring har

ness.

7, SECl and SEC2 are used to connect secondary side of

transformer to PCB. SECf is connected to equipment ground,

tl.

UNIT FUNCTIONS

A. Transformer NOTE: Terminals Tl, T2 (^if used), and T3 are wired to primary

or hi^h side of tr^nsfqmer.'The ^08-v tqrininal ‘(br blue wire'jf transformer Has‘ primary lfeads) is on 2D8^^^applica-’'" tjons, The 230-v tcoiimal (t;>r red witt) i$ iisAa^on'i’3'tpr 23Q-v

applications, T2 is a dummy terminal. 'i ■'■■i > ■

B. Electric Heat

NOTE: When troubleshooting dements, position thermostat to emergency heat. Wait approximately 12 minutes for all elements to

come On,

1. When thermostat calls for electric heat, a 24-v signal is sent to PCB through W2T, The PCE energizes first stage of electric heat.

TABLE 7—ELECTRIC

HEATER PART NO.

Heater Stage 1

KPAFH22Q1H1Q

KFAEH2301H15 15 kw Fused 3 8 11 15

KFAEH2401H20 ЙО kw Fused 6 10 15 20

10 kw Non-Fuaed 3

2. The first 2 stages come on if WZT and Y are energized at the same time. After each 10 minutes W2T iiS energized, another stage of electric heat is energized.

3. As W2T is de-energized, electric heat, stages down in S minute steps with the exception of first step. The first step will be on only half as long as -it was prior to W2T de-energizing. -y-.,

4. When W2T is energized by itself, JWl is cut, and an outdoor thermostat is used and is open, staging is limited as

in Table 7,

5. When bAlh. W3 and W2T are energized without JWl being

cut'or with outdoor thermostat closed, system operation

.! stagesdieat up to maximum level if signal is energized for

ргоры gpiouhi:_pf .time,

6/ If'órilyFW3 is energized, there is no effect on PCE, No heat

.iS'^nergiicid..

C. Acces^Órics

Terminals AU^-t- and AUX- áre energized with 24 vdc when fan is energizetl. The accessbry kit KFAIROIOIACR is used to connect'aii EAC or'humidifier. NO.TjE: "Loads cannot^be connected directly to AUX+ and AUX". Us,e the specified kit only.

D. Blower

1. Blower On Dclay—To optimize comfort, there is a 30-sec blower on delay in heat pump heating mode only.

HEATER STAGE LIMITING

STAGES (KW OPERATING)

W2T Only (JW1 cut)

2 3 4 6 9 9

A94127

W2T and W3

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UTC TECH PUB

F A X N o , 3 1 7 2 4 0 5 6 6 2

2. Blower Off Delay—Smart Heat control uses a 60-scc off blower delayj as opposed to the standard 90-sec delay.

IIL SMART HEAT OPERATION

A. Cooling

The Smart Heat option controls cooling mode in same manner as conventional heat pumps are controlled. The fan has a 90-sec delay

off/oji cycle down,

B. Heat Pump Heating

The Smart Heat option docs not control heating in the conventional method. The PCB energizes compressor 30 sec before indoor fan is energized. This allows indoor coil to heat up eliminating cold-blow on start“Up,

The electric heat is staged-on to allow continuous operation of heat pump and electric,resistance heat below balance point (below point where heat pump cannot maintain dwelling temperature without supplemental heat) independent of outdoor thermostats.

Although PCB has provisions for an outdoor thermostat, it is not needed for staging. On cycle down, indoor fan remains on 60 sec to recover heat stored in indoor coil,

C- Defrost

The Smart Heat PCB stages the correct amount of supplemental

heat during defrost. If too much heat is added, system stays in

defrost for completion of defrost cycle even though thermostat is satisfied. On next cycle, 1 less element is energized during next defrost period.

NOTE: If 24-v power from thermostat is inteiiupted while unit is

in defrost mode, the default cycle will be completed before unit shuts down.

P. Troubleshooting PrInted-CIrcult Board (Diagnostic LED)

The PCB of Smart Heat option heater package contains a micro processor which controls fan operation, fan speed, outdoor unit, and heater elements. Bor troubleshooting, a service LED Indicates condition of PCB, Sec Tabic 8 for LED flash codes,

TABLE 8—LED CODES FOR SMART HEAT PCB

FLASH CONDITION INPUT SIGNALS SYSTEM OPERATION

No Light/Flash

Steady Light

Steady Flash

1 Flash

2 Flashes Y and/or W2T

3 Flashes Y and/or W2T

4 Flashes Y and/or W2T 5 Flashes

6 Flashes Y, W2D. and/or W2T Defrost Mode 7 Flashes W2T Emergency Heat Mode

IV. ELECTRICAL OPERATING SEQUENCES AND

TROUBLESHOOTING

NOTE: Refer to Table 9 for proper input and output voltages.

A. Ready-To-Start

In rcady-to-start (standby) mode, LED on board indicates a steady flash.

In this mode, 24-v power should be available at control's low

voltage terminal strip terminals R and C. If 24v is not present

across R and C, check the followiug:

—

Yonly

Y. 0

No Power or

Board Failure Board Fallura

Stand By Condition

or Fan Only

Heat Pump Only

Operating

Heat Pump Plus

1 Sequencer

Heat Pump Plus

2 Sequencers

Heat Pump Plus

3 Sequencers

Cool Mode

* Is low-voltage fuse on control board good? ' Are line voltage fuses FUl and FU2 good?

■ Is LED on control on steadily or not on at all? Both of these indications signal a possible board failure.

‘ Is 2ÜS/230-V power available to control across pins 7 and 9

of 9-pin connector? Is connection to board tight?

B. Continuous Fan

On a call for continuous fan, thermostat provides a 24-v input signal to G terminal on low-voltage terminal strip. Sensing this signal, the microprocessor euergizeiS a relay on control to provide

power to high-speed winding of fan motor, at 1. The fan continues

to run until fan switch on thermostat is turned off.

During continuous fan operation with no call for heating Or cooling, LED indicates a steady flash, the same indication seen when system is in standby.

The call for continuous fan operation signal can be checked by placing voltmeter leads across terminals G and C of control’s low-voltagc terminal strip. If 24v is not seen across these termi

nals, check for the following:

’ Is 24v ayailable across R and C? If not, refer to Ready-To-

Start section for items to check if 24v is not available,

■ Is thermostat function switch set for continuous operation?

Confirm fan operation. Voltage to operate fan can be confirmed by placing.voltmeter leads across terminals FI and Ш on control. The reading should be 20S/230vi If 20S/230v is not observed, check the following:

* Is 20S/23ÜV available at pins 7 and 9 of 9-pin connector? Is

connection to board tight?

' Arc line voltage fuses FUl and FU2 good?

If 20&/230V is available across terminals FI and HI and fan does not operate, check the following:

* Is fan motor capacitor good?

‘ Is blower wheel jammed or loose? Are there any other

mechanical problems preventing fan operation?

C. Cooling

On a call for cooling, room thennostat provides input signals to control board at terminals Y and O'.' Thc О signal is also available to heat pump to energize reversing valve.

When it receives both these signals, the microprocessor responds

by providing a 24-v output signal at the terminal. This output signal energizes contactor in heat pump and starts compressor. There is a 3 to 5 sec delay in output of signal.

At the same time, control energizes fan coil's fan motor on high Speed through terminals FI and HI, The LED indicator on control signals 5 flashes, indicating cooling operation.

The call for cooling signals can be confirmed by placing voltmeter leads across low-voltage terminals Yl 0, and' C, The reading should be 24v. If 24v is not available, check the following:

* Is 24v available across R and C? See Ready-To-Start section

for items to check if 24v is not available.

* Is thermostat function switch set in COOL position with

thermostat calling for cooling?

Assuming heat pump has power and is adequately charged, it should be running at this time in cooling mode. Indoor fan should also be running at this time. If indoor fan is not running, refer to Continuous Fan section for items to check.

D. Heating (Compressor Only)

On a call for heat, room thermostat provides an input signal to control board at terminal Y. This signal causes the microprocessor to provide a 24-v output signal at terminal to energize contactor in heat pump. There is a 3 to 5 sec delay in output of Y,, signal.

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UTC TECH PUB

TABLE 9--TROUBL1ESHOOTING VOLTAGE READINGS AND TEST POINTS

LOCATION

Li and L2

L3 and L4

9-pin connsctpr 7 and 9

T1 and T3

NORMAL READING

206/230 vac 205/230 vac

208/230 vac

206/230 vac Power to transformer

SEC1 and SEC2 24 vac

n and C 24 Vac •Power from transformer secondary

G and C 24 vac

Y and C

O and C 24 vac

W2TandC

W2D and C , .24 ,vac

LOCATION HI and F1 LO and.Fl

and C '

’9-pin connactor

1 and 4 9-pln connector

2 arid 4 9-pln connector

3 and 4

Vac—vetts AC

vdD-^/oltS DC

24 vac

24 vao

NORMAL READING

208/230 vac 208/230 vac

24'vac Power to energize contactor in heat pump (heat and cool modes)

24 vdC

24 vdc

Thirty Sec after Y is energized, control energizes fan motor. It may run on high or low speedy depending on its operation in previous cycle.

Compressor operation in current cycle is monitored by the smart control to determine whether a fan speed change is required for enhanced indoor comfort. The LED indicator on control signals 1

flash, indicating compressor operation only with no ejegtric heat.

The call for heat signals can be confirmed by placing voltmeter leads across dow-‘voltag6 terminals Y, and C; The readings should be 24v, -If 24v is not available, eheck the following:

■ Is 24v available across R and'C? See Rcady-To-Start section for items to chedk if 24v is not available.

* Is thermostat function switch set in HEAT position with

theimostat calling for heat?

Assuming heat pump has power and is adequately charged, it should be running at this time in heating mode. Indoor fan should also be running at this time. H indoor fan is not mnniog, refer to , Continuous Ran section for items to check- When room thermostat is satisfied, indoor fan continues to run an additional 60 sec to recover heat remaining in indoor coil.

E. Heating (Compressor end Electric Heat)

If heat pump alone cannot satisfy heat requirements of structure, room thermostat calls for additional heat by way of an input to W2

terminal of control. When this occurs, control begins sequencing on electric heaters by energizing the first sequencer. Indoor fan should be running at this time.

If room temperature requirements cannot be met, additional stages

of electric heat are energized through the other 2 sequencers, at 2.

The logic of control determines how much and bow soon these additional stages are brought on. By observing LED status light, the number of operating stages of electric heat can be determined.

The control also varies indoor fan speed depending on number of

energized stages of heat. In general, the more stages of electric

heat, the higher the fan speed.

N o , 3 1 7 2 4 0 5 6 6 2

7 0 2 7

INPUT VOLTAGES

PURPOSE Main power supply Input to fen coil. Power to electric heaters

Power to smart control

Power from transformer secondary

Call for continuous fan signal from room thermostat Call for heat/cool signal from room thermostat Signal to energize reversing valve from room thermostat (cooling). Also present

during defrost, Call for eiectric heat from room thermostat Defrost initiation signal from heat pump

___

OUTPUT VOLTAGES

; ; PURPOSE Power to blower motor (high speed) Power to blower ,motor_(low speed)

Power to energize SEQ 1

NOTE: Sequencers use DC voltage

Power to energize SEQ 2

Power to energize SEQ 3

There is no hard and fast rule for detennining exactly when stages will be energized since microprocessor in the smart control constantly monitors duration of previous heating cycle, setting of room thermostat, and number of stages of heat needed in previous cycle to satisfy room thcmiostat. Rather than try to determine what should be operating when, service technicians should check LED status light to see how many stages of electric heat are energJKfid at a given time and confirm operation of sequencer using a voltmeter. If a quick check of all stages is desired, set room

thermostat as high as it will go. With a constant signal on W2T terminal, sequencers energize every 10 minutes until all heaters are on.

The previous paragraphs described how to' check for low-voltage inputs to control by placing voltmeter leads across low-voltage terminal strip and checking for 24v, The call for electric heat can

be confirmed by placing voltmeter leads across W2T and C. To check for operation of" sequencers, check' directly across

appropriate sequencer coil for 24 volts DC, NOTE: All sequencer coils are powered by 24 volts DC. This

voltage is generated internally by the smart control. In this example, sequencer 1 is being checked. The procedure is

the same for all other sequencers. If 24 volts DC is not observed,

check the following;

* Is room thermostat calling for electric heat? This can be

confirmed by checking for 24 volts AC between low-voltage terminal strip terminals W2T and C-

* Is LED flashing appropriate code for number of sequencers

energized? In this example, 2 flashes should be visible, indicating 1 sequencer is energized. Indicator tells how many sequencers are energized, but docs not tell which ones are.

' Is 9-pin connector for heater package tightly secured to

control board?

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FAX No, 31 7 240 5662

P, 028

R Checking Sequencer Operation

To check for operation of power circuit of ¡sequencer, place voltmstsr leads across sequencer teroiinal 1 of sequencer 1 and terminal 4 of limit switch 3. The reading should be 208/230v, and heater should be energized.

If 20S/230v is not observed at teritiinals specified, check the

following:

• Are fuses FU3 and FU4 good? * Is limit switch LS3 Open? If so, check fan coil air filter or air

distribution system for blocking or restriction that might

reduce airflow pud cause limit switch to open.

Operation of heaters can be confirmed^fiiither by using a clamp-on ammeter in circuit shown to verify current is flowing through heaters. Amperage readings will depend, on size of heater. The procedure fOr checking other sequencers in system is identical to that just described,

G. Emergency Heat

Emergency heat mode requires that room thermostat be placed in EMERGENCY HEAT position. This locks, out and prevents operation of heat pump outdoor unit. In tlits mode, heat is provided exclusively by electrical heaters in fan qoil.

In this mode, room thermostat, at 1, provides'an enaergency heat input signal to smart cdntrol at teiminaj WZT, If jumper JWl, at 2, has not been cut and an outdoor .thermostat installed to control electric heat stages, that samc input signal is applied to tcmiinakJ> W3. For this example, assume that jumper JWl has not been cut-

Evcntually, the total number of heaters is cycled on. In emergency heat mode, LED iijdicator signals 7 flashes.

The amount of emergency heat available depends on whether jumper JWl is cut and the nupiber of heatiji^ elements. Table 10 illustrates results under various conditions. The heaters cycle on every 5 minutes until maximum level is reached.

TABLE 10—EFFECT OF JW1 ON EMERGENCY HEAT

jWi cut*

4 elements

50%

JW1 not cut

4 elements

100^

Outdoor thermostat opens

With cut, an-outdoor thermostat (if closc^) could cycle on additional heaters and system would perform as if JWl was not cut. In effect, closed Outdoor thermostat replaces cut jumper,

3 elements

66.7%

3 elements

100%

H. Defrost

In defrost mode, LED indicator signals 6 flashes. Defrost is initiated by heat pump and is signalled to smart control by an input to W2D terminal During defrost, outdoor unit switches to cooling mode, making it necessary to cycle on electric heaters to temper indoor air.

If electric heaters were not energized prior to defrost, smart control energizes ’sufficient elements to temper air. If heaters were energized prior‘to defrost, additional heaters may ОГ may not be

cycled on to provide additional heat-

Л defrost initiation signal can be confirmed by attaching voltmeter leads ac/oss low-vcjltage terminals W2D and C. If 24v is not

observed, check the following;

* Is 24v available across R and C? See Ready-To-Start section

for items to check if 24v is not available,

* Is there continuity in thermostat leads between heat pump

and smart control?

* Is defrost control in heat pump operating properly?

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THIS COMPARTMENT MUST BE CLOSED EXCEPT FOR SERVICING

UTC TECH PUB

F A X N o , 3 1 7 2 4 0 5 6 6 2

P .

1. USE COPPER WIRE (75-C MIN) OMLVa^EEM DISCONNECT SWITCH AND UNIT. "v,

2. CONNECT LOW VOLTASE WIRINS AS SHOWN (24VAC).

3. CONNECTTHANSFOñMÉflPRIUAHYTO-mEPHOPER

VOLTAGE TERMINAL

4. TO BE WIRED IN ACCORCJANCE WITH NEC AMD LOCAL CODES

5. IP ANY OF THE ORIGINAL WIRE,AS 5UPPUED, MUST BE

REPLACED. USE THE SAME OH EQUIVALENT TYPE WIRE

e, REPLACE LOW VOLTAGE FUSE WITTi NO GREATER THAN

6 AMP FUSE.

7, REFERTOTHSHMOSTATINSTRUCnONS FOR'E'JUMPER

INSTAliATlON.

B, DOHOTCQNNECTTHERMOSTAT’E" to PCB ’W3".

MINIMUM MOTOR LO SPEED TAP SELECTION

FAN COIL SIZE

l^MGTOR speed AT 20 KW

030

MED

033 030

MED

035

LO LÖ LO

042 043 030

CAP CAPACITOR COMM COMMON F LOW VOLT FUSE

FW FAN MOTOR

GND EQUIPMENT GROUND

hplV heat pump LOW volt

HTR HEATffl

ls umit switch

070

LO LO

Fig. 23—Sm^rt Heat Typical Wiring Diagram (Motor Speed at 20kw Shown)

322251-101

REV.B

DtAGNOSTIC LIGHT O

LED

LOW VOLT TERM BRD

LVTB

SEQUENCER

SEQ

TRANSFORMER

TRAN JiFQRM PCBTHANTERMINAL8

---------

REID LOW VOLTAGE

HPLV LEADS

1 PUSH

£ FLASHES

3 FLASHES

4 FLABHHS

A FLASHES

0 MARKED TERMINAL 6 FLASHES

------

1 PCB JUMPER (JW)

a UNMARKED TERMINAL

7 FIASHE6

HEAT PUMP H^T

ONLY OPERATING

HEAT PUMP PLUS

iSEQUENCER .

HEAT PUMP PLUS

a SEQUENCERS

HEAT PUMP PLUS

3 SEQUENCERS

COOLMODE

DEFROST MODE

EMERGENCY HEAT

MODE

A94132

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Packaged Service Training programs are an excellent way to increase your knowledge of the equipment discussed in this manual, including:

A large selection of product, theory, and skills p[ograrris is available, using popular video-based formats and materials. All include video and/or slides, plus companion

hook.

Classroom Service Training plus "hands-on" the productejn our.labs can mean increased cxjnfidencelhat.reaily pays.dividehdsjn faster .tjpubleshooiing, fewer callbacks. Course descriptions and schedules are in our catalog,

UTC TECH PUB

F A X N o , 3 1 7 2 4 0 5 6 6 2

SERVICE TRAINING

• Unit Familiarization • Maintenance

• Installation Overview • Operating Sequence

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[] Packaged Service Training [ J -Classrddrn Service Training

Afl432S

® i33G BDP Co,' KO. 7d ‘ Indianapolte, ipJ 4^206 Print0{J In u,s,A, _30 —

14072 Calalng No. 92-33FA-416

Bryant FA4A User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

, i SAFETY CONSIDERATIONS

^I3anc0ls; SM03-1

INTRODUCTION

UNIT IDENTIFICATION

I. PRINTED CIRCUIT BOARD (PCB) COMPONENT LAYOUT AND DESCRIPTION

II. UNIT FUNCTIONS

A- Transformer

B. Indoor Fan

pig. 4—^Wiring Diagram

I. DESCRIPTION OF ELECTRIC HEATER COMPONENTS

A. Limit Switch

II. TROUBLESHOOTING KFA AND KFB SERIES

A. Discolored Wire Insulation at Tormincl

C. No Heat

D. Heater Will Not Turn Off

I. INTEGRATED CONTROLS AND MOTOR (ICM2)

И. CFM Select Configuration Taps

IV, EASY SELECT CONFIGURATION TAPS

A. Auxiliary Heat Range

Fig, 6—Easy

Select Board

V. TROUBLESHOOTING PCB

A. If Fan Wilt Not Turn On Ftom Thermostat:

320486-301 REV. C

C. If PCB Fuse Keeps Blowing:

B. If Motor Does Not Run Smoothly;

C. If Motor Shaft Does Not Rotate Smoothly:

VII. CONDENSED VERSION OF TROUBLESHOOTING FK4B MOTOR AND CONTROLS

+ ROOM THERMOSTAT

THERMOSTATIC EXPANSION VALVES (TXV)

I. PROBLEMS AFFECTING TXV

A. Low Suction Pressure

B. High Suction Pressure

PISTON BODY CLEANING OR REPLACEMENT

LIQUID TUBE STRAINER

I. A-COIL UNITS

II. SLOPE COIL UNITS .

I. FILTER ASSEMBLY

II. COOLING COIL, DRAIN RAN, AND CONDENSATE DRAIN

CARE AND MAINTENANCE

III. BLOWER MOTOR AND WHEEL

FF1A/FF1B SERVICE AND TROUBLESHOOTING

L FAN MOTOR

II. ELECTRIC HEATER SERVICE

A. Limit Switch

C. Transformer

NOTE: Transformer is fused. Do not short circuit. D. Fan Relay

IV. LIQUID TUBE STRAINER

V. SEQUENCE OF OPERATION

COOLING

316596-401 REV. B

HEATING

FD3A SERVICE AND TROUBLESHOOTING

1. FAN MOTOR

li. ELECTRIC HEATER SERVICE

A. Limit Switch

D. Fan Beley

E, Heater Removal

40DQ500784 REV. C

)V. LIQUID TUBE STRAINER

V. CARE AND MAINTENANCE

A. Motor ......................

B. Coil, Drain Pan, and Condensate Drain

Fig. 21—Checking Pulley Alignment and Tightness

II, MAINTENANCE

A, Return-Air Filter

I. PCB COMPONENT LAYOUT, DESCRIPTION, AND FUNCTION

UNIT FUNCTIONS

B. Electric Heat

TABLE 7—ELECTRIC

C. Acces^Órics

D. Blower

HEATER STAGE LIMITING

IIL SMART HEAT OPERATION

A. Cooling

C- Defrost