NumberOne
Air(3onditoning
Maker
e
Division of Carrier Corporation
Carrier Parkway • Syracuse NY 13201
Air-Cooled Condensing Units
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-the- wall, 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.
Table 1 — Physical Data
COND UNIT |
|
SS^GKOOl |
38GK002 38GK003 |
|
OPER WT (lb) |
|
144 __ |
162____ 186 |
|
R-22 CHG (Ib-oz) |
|
2j3 _ |
.3^5 |
~ 4Ì3 |
COND FAN |
|
Twin Centrifugal Biowers — |
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|
|
Direct Drive |
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D i scharge |
|
Hori zontal |
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Motor Hp |
|
|
V4 |
|
Rpm |
|
|
1550 |
|
Diom + Width (in.) |
|
|
6^6+514 |
|
DIM. (ft-in.) |
|
|
2-2Va |
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Length |
|
|
||
Width |
|
|
1- |
4% |
Height |
_ |
|
2- |
4% |
CONN.* (in.) |
|
|
|
% |
Suction (ODF) |
|
% |
|
|
Liquid (ODF) |
|
|
% |
|
*Units are equipped with Carrier Compatible Fittings for refrig erant connections
Table 2 — Installation Data (ft-in.)
COND UNIT |
|
! 38GK001 | 38GK002 ] 38GK003 |
|
1/ |
II |
|
|
THRU-THE-WALL |
2-2% X 2-5 |
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CLEARANCE DIM. |
|||
|
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AIR CLEARANCE |
3-0 |
||
CONCRETE MOUNTING |
2-3 X 1-5 X 0-5 |
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PAD DIMENSIONS |
|||
|
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SERVICE |
Ends |
0* |
|
CLEARANCE |
Bock |
1-6* |
|
"Units are serviced from rear access panel Therefore, units can be installed with 0-in end clearance
Certified aimensionarawlngs available oh request .................................. .............................................. ..
Fig. 1 — Dimensions and Connections
© Carrier Corporation 1976 |
Foim 38GK-4SI |
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.
2. Tilt to the front to allow the water to drain off. See Fig. 3.
3.Fasten the unit to the frame with metal straps.
4.Use flashing under the unit and caulk all edges to provide a weathertight seal (Fig. 3).
Fig. 3 — Flush or Recess Mounting
Table 3 — Recommended Liquid Line Sizes
|
MAX |
COND* |
REFF |
|
COND |
UNIT HT (ft) |
|||
|
||||
UNIT |
Above |
Below |
0-49 |
|
|
Evap |
Evap |
Liqu |
|
38GK001 |
40 |
50 |
|
|
38GK002 |
40 |
70 |
% |
|
38GK003 |
40 |
60 |
|
|
Crankcase heater required |
|
|
|
*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 |
|
|
|
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 4 — Recommended Suction Line Diameters
UNIT |
MODEL |
SUCTION LINE |
SUCTION LINE |
|||
LENGTH (ft) |
DIAMETER (in.) |
|||||
|
|
|||||
|
|
0 |
|
46 |
=/B |
|
38GK001 |
(All) |
47 - |
120 |
% |
||
|
|
121 - |
150 |
VB* |
||
|
|
0 - |
28 |
% |
||
38GK002 |
(All) |
29 - |
72 |
VB |
||
|
|
73 - |
150 |
VB* |
||
|
|
0 |
- |
19 |
V |
|
|
|
/4 |
||||
38GK003 |
201 |
20 |
- |
52 |
V |
|
'A |
||||||
|
|
53 |
- |
116 |
7/* |
|
|
|
|
||||
|
|
0 |
- |
18 |
% |
|
38GK003 |
301 |
19 |
- |
48 |
% |
|
|
|
49 |
- 107 |
VB* |
||
|
|
|
|
|
|
|
*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 |
|
|
|
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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