Carrier 50QT User Manual

Carrier Corporation • Syracuse N Y 13221

Single-Package Heat Pumps

Chassis Only (Install ONLY after

50OT wall sleeve is in place)

CONTENTS

Page

SAFETY CONSIDERATIONS

INTRODUCTION .......................................................1

INSTALLATION.......................................................1-4

Step 1 — Check Equipment and Jobsite .. I

• UNPACK UNIT

• INSPECT EQUIPMENT

• INSPECT WALL SLEEVE

Step 2 — Install Chassis in Wall Sleeve.... 3

• SLIDE CHASSIS INTO SLEEVE

Step 3 — Install Thermostat and

Connect Thermostat Wiring....................................3

• TO MOUNT THERMOSTAT IN UNIT

• TO MOUNT THERMOSTAT REMOTELY

COLD CLIMATE ACCESSORY START-UP SERVICE

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

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

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

4 4

4-14

SAFETY CONSIDERATIONS

Installation and servicing of air conditioning equipment can be hazardous due to system pressure and electrical components. Only trained and quali fied service personnel should install, repair or service air conditioning equipment.

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INTRODUCTION

Install Model 50QT112, 115 and 118 heat pump chassis in 50QT wall sleeve. Part No. 50QT900060; and Model 50QT124 and 130 chassis in 50QT wall sleeve. Part No. 50QT900080. Wall sleeves are shipped separately with aecompanying installation instructions. All electrical power, ductwork and condensate drain hookups are made at time of wall sleeve installation.

Untrained personnel can perform basic mainte nance functions of cleaning indoor coil or replacing filter. All other operations should be performed by trained service personnel. When working on air conditioning equipment, observe precautions in the literature, tags and labels attached to the unit and

other safety precautions that may apply.

Follow all safety codes. Wear safety glasses and work gloves. Use quenching cloth for brazing operations. Have fire extinguisher available for all brazing operations.

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INSTALLATION

Step 1 — Check Equipment and Jobsite

UNPACK UNIT — Move to final loeation. Lift eardboard carton off chassis taking special care not to damage unit.

Form 50QT-10SI

Table 1 — Electrical Data (&©^zt

MODEL

50QT

112300 II

115300

118300 AD

AF AD

124300 AF

AG AD

130300 AF

♦Permissible limits of the voltage range at which units will

operate satisfactorily

fField wiring to be sized for NEC or local codes Use copper wire

only

^Maximum dual element fuse

♦♦Minimum voltage is 197 when outdoor ambient temperature

exceeds 105 F

NOTE: Dual values in this table (for example Electric Fleeter Amps 9 4/12 5) apply to 208- and 230-volt connections respectively

V/PH

208/230/1

OPER

VOLTAGE^

Max Min^*

254 187 37 6 8 1 5 1 0

254

254 187 59 13 0 2 0

254

187

COMPR

LRA

43 8 7

IFM OFM

RLA FLA

1 5

10 3

1 7

16 9 2 4

ELECTRIC

HEATER

AMPS

FLA

9 4/12 5

18.0/20.8

1 0

1 5

9 4/12 5

18 0/20 8

9 4/12 5 18 0/20 8 26 8/31 3

17 3/20 8 26 8/31 3 36 1/41.7

17 4/ 20 8

26 8/31 3 36 0/41 7

FLA — Full Load Amps

FIACR— Heating, Air Conditioning IFM — Indoor Fan Motor

Max Fuse or

.....

These units require 2 separate supply circuits Refer to BOTFI branch circuit charts for complete

electrical data

and Refrigeration

BRANCH CIRCUIT #1

(or Total Unit)t

HACR Ckt

Bkr Ampst

25/30 35/40

30/35 40/45 50/55

45/50 55/60

MCA

22 8/26 6

33.5/37.0 25 1/29 0

35.9/39.4 27 3/31 2

38 1/41 6 49 1/54 7

41 4/45 9

53.6/59.1

50/55 ^ 1 47.5/52J

BRANCH CIRCUIT #2

(When Used)t

Max Fuse or

HACR Ckt

Bkr Ampst

—

LRA — Locked Rotor Amps MCA— Minimum Circuit

Amps

OFM — Outdoor Fan Motor RLA — Rated Load Amps

MCA

—

♦INSPECT EQUIPMENT for damage prior to in

stallation. To remove plastic wrapper, grasp bottom and pull out until velcro strips separate. To remove metal cover plate, remove 6 screws. Eile claim with shipping company if shipment is damaged or

incomplete.

Leave chassis bolted to skid and replace metal cover plate, plastic wrapper, and carton until ready for installation into wall sleeve.

INSPECT WALL SLEEVE installation for damage. Condensate drain pan must be free of debris and installed in accordance with local build ing regulations. Electrical connector on left side of sleeve should be free of dirt, grease, paint, etc.

Connector must be properly wired before chassis

installation. Duct connection panel must be level and duct connections complete. Do not rest weight

of ductwork on duct connector panel. Inspect name

plate on sleeve to ensure wire and fuse sizing is

correct for model size to be installed.

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-i

Fig. 1 — Chassis with Indoor Plastic Wrapper

Step 2 — Install Chassis in Wall Sleeve —

Remove sleeve filler panel and save screws. Install outdoor grille using these screws. Remove indoor plastic wrapper as described in Step 1. Do not handle cha.ssis with plastic wrapper in place.

SLIDE CHASSIS INTO SLEEVE — Chassis is

heavy. Portable lifting device must be used. Exercise caution to make sure forks do not damage chassis components (such as drain connections) while

lifting and installing. Guide chassis into sleeve on

indoor side by first placing chassis guide channels

onto sleeve guide channels at bottom of sleeve.

Slide chassis into sleeve until center partition peri

meter meets gasket provided around outer edge of

sleeve. Check electrical plugs for alignment as

chassis is slid into place.

Tighten chassis into place by driving 6 screws, provided in separate bag with chassis, into nuts provided on sleeve (see Fig. 3).

Electrical and condensate drain connections are

complete when chassis is installed correctly into

sleeve.

Step 3 — Install Thermostat and Connect Thermostat Wiring — (Thermostat and subbase

are packaged separately with unit shipment.) Thermostat can be installed in 50QT or in remote location.

TO MOUNT THERMOSTAT IN UNIT;

1. Remove metal cover plate by removing 6 screws.

2. Locate and install subbase onto thermostat bracket running between right and left coil par tition (see Fig. 3). Push plug and wires through hole provided.

3. Connect plug from subbase to mating socket located on left coil partition (see Fig. 3).

4. Attach thermostat to subbase and snap on thermostat cover.

5. Cut hole in stenciled area on back side of wrapper with a sharp utility knife.

6. Cut and remove insulation from hole in metal cover plate.

7. Replace metal cover plate.

TO MOUNT THERMOSTAT REMOTELY:

1. Pull subbase extension cord, previously installed, up into the return air inlet. Plug cord into mating socket on the left-hand coil partition. (See Fig. 3.)

FUSIBLE-

PLUG

CRANKCASE HEATER THERMOSTAT

50QT112, 115, 118

^Accumulator and compressor location reversed on 50QT112 tCompressor guard removed

Fig. 2 — Outdoor Component Location

OUTDOOR COIL

00 FAN MOTOR (PROPELLER FAN REMOVED TO SHOW MOTOR)

COMPRESSOR MOUNTING PAN

CHASSIS GUIDE CHANNEL

50QT124, 130

^Outdoor fan guard and compressor guard removed to show

components

ACCURATER LOCATION

MAIN CONTROL BOX COVER

MATING SOCKET

LOCATION

INDOOR NAMEPLATE LOCATION

THERMOSTAT MOUNTING BRACKET

50QT112,115,118

ELECTRIC HEATER CONTROL BOX COVER

CHASSIS MOUNTING BOLTS (6 TOTAL)

SLEEVE ELECTRIC HEATER JUNCTION LOCATION BOX ACCESS PLATE

MAIN CONTROL

BOX (SLIDES OUT FOR servicing:

CENTER PARTITION

INDOOR COIL CONDENSATE

DRAIN LEFT COIL PARTITION

INDOOR NAMEPLATE LOCATION

Fig. 3 — Indoor Component Location

THERMOSTAT PLUG

50QT124,130

ELECTRIC HEATER COVER

./INDOOR FAN

MOTOR (NOT VISIBLE)

DEFROST

/THERMOSTAT ON

LIQUID LINE LOW-PRESSURE

SWITCH

v(NOT SHOWN)

^COMPRESSOR

SUCTION SERVICE PORT

BRIGHT COIL

■ PARTITION

ROOM THERMOSTAT

(CAN BE MOUNTED

REMOTELY)

INDOOR AIR FILTER

2. Plug other end of cord, hanging from the wall at its remote location, securely into subbase.

3. Push plug and excess leads into wall hole. Cover hole appropriately to avoid incorrect thermostat

readings.

4. Mount subbase onto wall.

5. Attach thermostat to subbase. Snap on cover

and install chassis indoor cover.

> COLD CLIMATE ACCESSORY

Cold climate accessory should be installed on 50QT100 units where the outdoor ambient tem perature consistently falls below 30 F. Cold climate accessory is available in both six packs and single packs as indicated below: for 50QT112, 115, 118 —

accessory part no. 50QT90016106 (six pack) or 50QT900160 (single pack); for 50QT124, 130 — accessory part no. 50QT90017106 (six pack) or 50QT900170 (single pack).

START-UP

Crankcase Heater — The 50QT compressor is

equipped with a crankcase heater that is thermo statically activated in cold weather. (See Fig. 2 and

3.) If temperature is below 65 F, operate crankcase heater 24 hours before starting unit. To energize crankcase heater only, after chassis installation, set thermostat to <C > ^position and turn on unit power at disconnect switch.

Thermostat Anticipator — Room thermostat anticipator settings for all 50QT heat pumps is

0.20 amps. This setting may be changed slightly to

provide a greater degree of comfort fora particular installation.

To Start Unit — Check that main power is on and, if temperature is below 65 F, that compressor crankcase heater has been energized for at least

24 hours.

1. Set selector switch at*C •

2. Set fan switch as desired (FAN) (AUTO.).

3. Set thermostat lever at the desired temperature.

4. Set selector switch at HEAT or COOL. Check system refrigerant charge. See Refrigerant

Charging.

SERVICE

Low-Pressure Switch (Safety Control) is lo

cated on liquid line downstream of AccuRater™ control during cooling mode (or upstream of Accu

Rater control during heating mode). Switch opens at 5 psig and shuts down compressor to protect it

from overheating if refrigerant charge is too low.

High and low side pressure connections are acces

sible from the incloor portion of the unit for

charging. (See Fig. 3.)

High-Pressure Relief Valve (Safety Control) is located in compressor. Relief valve opens at a pres

sure differential of approximately 450 ± 50 psi between suction (low side) and discharge (high side) to allow pressure equalization.

Internal Current and Temperature Sensitive Overload (Safety Control) re.sets automatically

when compressor motor temperature drops to a safe level (overloads may require up to one hour to reset).

When an internal overload is suspected of being open, check by using an ohmmeter or continuity tester. If necessary, refer to Carrier Standard Service Techniques Manual, Chapter 2, Electrical, for complete instructions.

Defrost Control, consisting of a defrost timer, defrost thermostat and defrost relay, interrupts normal system heating operation to remove frost and ice formation on outdoor coil. Frost impairs unit performance. Defrost control simultaneously stops outdoor fan, energizes reversing valve sole noid to switch system into cooling cycle (outdoor unit as condenser, indoor unit as evaporator), and activates electric heater. Unit can defrost every 90 minutes, but will do so only if outdoor temperatures are in the frosting temperature zone.

For heat pump to defrost, 2 conditions are

necessary:

1. Defrost timer contacts must be closed.

2. Coil temperature must be cold enough to cause defrost thermostat contacts to close.

Contacts close at 28 ±3 F (50QT112 - 118) and

35 ± 3 F (50QT124, 130). Every 90 minutes of elapsed running time, the defrost timer contacts close for 10 seconds. If the defrost thermostat contacts are closed, the unit defrosts. The defrost timer limits defrosting period to 10 minutes.

Normally the frost is removed and the defrost ther mostat contacts will open to terminate defrosting before 10 minutes have elapsed. Defrost thermostat contacts open at 65 ±5F (50QT112 - 118) and 75 ±5F (50QT124,130). When defrosting is terminated, the outdoor fan motor is energized and reversing valve solenoid is de-energized, re turning unit to heating cycle.

HEAT PUMP CIRCUITS shown in Fig. 4 are refrigerant flow diagrams for heating and cooling

cycles.

Refrigerant Charging

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Do not overcharge system. An overcharge can

cause compressor flooding.

Unit refrigerant system is factory charged. When

recharging is necessary, weigh in total charge indi cated in Table 2. (Charge must be weighed in during heating season.) Remove any refrigerant remaining in system before recharging. If system has lost com

plete charge, triple-evacuate system to 5000 microns (29.7 in. vacuum) before recharging. Service port connections are provided on unit suction and dis

charge lines for evacuation and charging. (See Fig. 4

for service port location.) Dial-a-charge charging

cylinder is an accurate device used to recharge

systems by weight. These cylinders are available at

refrigeration supply firms.

Table 2 — Service Data

UI\IIT50QT 112 MODEL R-22 CHARGE* (lb) 2 7 2 7 3 2

Refrig Control AccuRater™ Bypass Type

INDOOR FAN Centrifugal Blower,

Rotationt Rpm

Diameter (in ) Width (in.)

Range (cfm) Motor Hp

OUTDOOR FAN

Cfm

Rpm 1125 Diameter (in ) Motor Hp Vs

ccw cw

Counterclockwise Clockwise

1580

430/ 375

1700

115

300

Direct Drive, 2-Speed

CW CW CCW

1550 1570 1675

550/ 575/ 475 480

'A Vs.

Propeller, Direct Drive, Single Speed

1700 1700 2000 2000

‘Factory refrigerant charge fLooking at fan motor shaft

118

300

124 130

300 300

4 5

CCW 1675

7 7

885/ 800

1025/

'/4 V4

960

To check and/or adjust charge during cooling season, use Cooling Cycle Charging Charts (Fig. 5, 7, 9, II, 13) and follow Charging Chart Method below. The charging chart may also be used as an alternate method of recharging system.

To check system operation during heating cycle, use Heating Cycle Operation Check Chart (Fig. 6, 8,

10, 12, 14). These charts indicate whether a correct relationship exists between system operating pres sures and air temperatures entering unit. If pressure and temperature lines do not intersect on chart, the system refrigerant charge may not be correct or other system abnormalities may exist. Do not use Operating Check Charts to adjust refrigerant charge. Weigh charge into system.

COOLING CYCLE CHARGING CHART

METHOD

1. Operate unit a minimum of 10 minutes before checking charge, and after each charge adjustment.

2. Measure suction pressure by attaching a gage to unit suction service port. (See Fig. 4 for correct

service port location.)

3. Measure outdoor (coil inlet) air dry-bulb tem perature. Use service thermometer.

4. Using a sling psychrometer, measure wet-bulb temperature of air entering indoor fan coil.

5. Refer to Charging Chart. Locate on curves where outdoor air dry-bulb and indoor air wet-bulb temperature lines intersect.

6. From intersect point, project vertically down ward to chart suction pressure line. Compare

chart suction pressure to unit suction pressure

(Step 2).

7. If unit suction pressure is lower than chart pres sure, add refrigerant to system until chart

pressure is reached. If unit suction pressure is higher than chart pressure, remove refrigerant until chart pressure is reached.

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