Carrier 38GK User Manual

Number One Air(3onditoning

Maker

Division of Carrier Corporation Carrier Parkway • Syracuse NY 13201

Air-Cooled Condensing Units

Table 1 — Physical Data

INTRODUCTION

The 38GK condensing units are designed for use with Carrier approved evaporator coils or fan coils which have capillary tube or AccuRater refrigerant control. They may also be used with evaporators which have expansion valves that equalize pressure during the off cycle. If an expansion valve without pressure equalization fea

ture is used, add an accessory start capacitor kit to

condensing unit.

Install these condensing units either thru-thewall, outdoors on a slab or on the roof. When installing units, allow sufficient space for air-flow clearance, wiring, refrigerant piping and servicing

units. Consult local building codes and National

Electrical Code (NEC) for special installation re quirements. See Fig. 1 and Tables 1 and 2 for detailed unit installation data.

COND UNIT OPER WT (lb)

R-22 CHG (Ib-oz) COND FAN

D i scharge Motor Hp Rpm Diom + Width (in.)

DIM. (ft-in.)

Length Width Height _

CONN.* (in.)

Suction (ODF) Liquid (ODF)

*Units are equipped with Carrier Compatible Fittings for refrig

erant connections

SS^GKOOl 38GK002 38GK003

144 __ 162

____

186

2j3 _ .3^5 ~ 4Ì3

Twin Centrifugal Biowers —

Direct Drive

Hori zontal

1550

6^6+514

2-2Va

1- 4%

2- 4%

Table 2 — Installation Data (ft-in.)

COND UNIT ! 38GK001 | 38GK002 ] 38GK003 THRU-THE-WALL

CLEARANCE DIM. AIR CLEARANCE CONCRETE MOUNTING

PAD DIMENSIONS SERVICE

CLEARANCE

"Units are serviced from rear access panel Therefore, units can be

installed with 0-in end clearance

1/ A I I

Ends

Bock

2-2% X 2-5

3-0

2-3 X 1-5 X 0-5

1-6*

Certified aimensionarawlngs available oh request ..................................

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

Fig. 1 — Dimensions and Connections

INSTALLATION

Mounting Thru-The-Wall

An opening approximately 26-1/2 x 29 in. shall be made in a wall as close to a nearby cooling coil as possible. Refer to Fig. 2 to build a frame in a manner to support the condensing unit.

1. Locate unit with frame into the opening until the unit extends approximately 1 in. beyond the outside (finished) wall.

Tilt to the front to allow the water to drain off. See Fig. 3.

Fasten the unit to the frame with metal straps.

Use flashing under the unit and caulk all edges

to provide a weathertight seal (Fig. 3).

Fig. 3 — Flush or Recess Mounting

Fig. 2 — Roughing-ln Supporting Frame

REFRIGERANT LINE SIZING

Selection of Correct Liquid Line — See Table 3 for

maximum allowable vertical and horizontal dis

tance between condensing unit and evaporator

using recommended 3/8-in. liquid line.

Selection of the Correct Suction Line Diameter —

To keep line losses at a minimum, refer to Table 4

to select the correct suction line diameters.

Table 3 — Recommended Liquid Line Sizes

MAX COND*

COND

UNIT

38GK001 40 38GK002 40 38GK003

*Decrease maximum allowable vertical separation by 20% for

every 10 ft of refrigerant line length over 100 feet At 150 ft of line length, 0 ft vertical separation is allowed

UNIT HT (ft)

Below

Evap

50 70 60

Above

Evap

Crankcase heater required

REFF 0-49

Liqu

Table 4 — Recommended Suction Line Diameters

UNIT

38GK001 (All)

38GK002 (All)

38GK003 201

38GK003

*Field-supplied 7/8-in to 3/4-in adapter is required NOTE

The above table is based on a line loss of 2 F Longer lengths can be used in each diameter listed, but the result will be larger line losses Refer to Carrier, Syracuse Engineering Office for specific details

MODEL

301

SUCTION LINE

LENGTH (ft)

47 - 120

150

121 -

0 - 28

29 - 72

150

73 -

0 -

20 -

116

53 -

0 - 18

19 -

107

49 -

SUCTION LINE

DIAMETER (in.)

=/b

Vb*

7/*

% %

Vb*

INSTALLING REFRIGERANT LINES

General — The condensing unit is fully charged at

the factory. Be sure both service valves are frontseated (turned clockwise) to avoid loss of the charge. Do not remove refrigerant line connection

seals from the condensing unit, the matching coil, nor the refrigerant tubing, until ready to make the actual connection at the point of seal.

If accessory tubing package or evaporator coil has been open for more than 15 seconds per connection, evacuate or purge evaporator coil and tubing system (use field-supplied refrigerant, not unit refrigerant). Always evacuate or purge if field-supplied tubing is used. See Purging.

Ensure field-supplied tubing is of refrigerant grade. Insulate the suction line with insulation that has an adequate vapor barrier (Armaflex or

Ensolex). Evacuate tubing.

When a complete Carrier system is used, a

filter-drier is not required. However, if other than Carrier accessory tubing package or evaporator is used, or if refrigerant tubing or coil is exposed to

atmospheric conditions for longer than 10 minutes,

install a filter-drier in the system near evaporator

coil. Additional refrigerant must be added to the

system to compensate for the additional volume of

the filter-drier.

Installation

1. Run refrigerant lines as directly as possible, avoiding all unnecessary turns and bends.

2. Tape the liquid line to the top of the insulated suction line for support.

3. Suspend the refrigerant lines so that they do not damage the insulation on the suction line and do not transmit vibration to the structure.

4. If the refrigerant lines are too long, the lines should be rolled into a loop and placed in a horizontal plane, or the excess may be cut off.

5. Check to be sure both service valves are frontseated (turned clockwise). It is necessary to remove the valve stem caps to check.

6. Connect tubing to the condensing unit. The refrigerant tubing and evaporator coil should be leak tested upon completion.

Connection Procedure — When making piping

connections, be sure to provide clearance at unit for electrical connections.

Connect refrigerant liquid and suction lines to

condensing unit. Fig. 1 (page 1). Unit Compatible Fittings permit 2 methods of refrigerant line connection: mechanical (quick connect) or sweat connection. Make suction line connection first.

MECHANICAL CONNECTION (Mate one set of connections at a time.)

1. Loosen nut on Compatible Fitting one turn. Do not remove.

2. Remove plug and be sure 0-ring is in the groove inside the Compatible Fitting.

3. Cut tubing to correct length.

4. Insert tube into Compatible Fitting until it bottoms. Be sure tube is bottomed while nut is

being tightened.

5. Tighten nut until it bottoms on back coupling flange.

SWEAT CONNECTION (Use refrigerant grade tubing.)

1. Remove locking nut, rubber 0-ring and Schrader core from valve.

2. Cut tubing to correct length.

3. Insert tube into Compatible Fitting. Wrap top and bottom of service valves in wet cloth to prevent damage by heat. Solder with lowtemperature (450 F) silver alloy solder.

4. Replace Schrader core.

5. Evacuate or purge system with field-supplied

refrigerant.

Leak Testing

No installation is complete until all field and

factory joints have been checked for leaks.

1. Remove the valve stem caps from both service valves and check to be sure the valves are

frontseated (turned clockwise). Remove the

service port caps.

2. Attach a gage manifold to service ports of the service valves and purge the hoses.

3. Pressurize the evaporator coil and the inter

connecting refrigerant tubing with vapor from an external refrigerant cylinder of R-22 until the system and cylinder pressures are equalized. NOTE: NEVER USE A UNIT CHARGE FOR LEAK TESTING.

4. Leak test with an electronic detector, a halide

torch, or a liquid soap solution.

5. Release the pressure and repair any leaks found.

6. If the system is to be purged or evacuated, leave

the service valves in the frontseated position.

7. If the system is free of leaks, you may then

prepare the unit for operation by: a. Backseating (turn counterclockwise) both

service valves.

b. Removing the gage manifold.

c. Replacing the caps on the service port and

valve stem.

Purging — To purge unit, do not use the unit

charge Proceed as follows:

1. Remove the valve stem caps from both service valves and check the valve stems to be sure they

are frontseated (clockwise).

2. Remove the service port caps from both service valves and connect a refrigerant cylinder of

R-22 to the service port of the liquid line service valve.

3. Open the refrigerant cylinder valve and allow

approximately 1/2 to 1 pound of refrigerant to flow thru the system and out the service port on the suction line service valve.

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