Carrier 38HDR User manual

38HDR
Ducted Condensing Units
Installation Instructions
A07532
Fig. 1 --- 38HDR
NOTE: Read the entire instruction manual before starting the
installation.
TABLE OF CONTENTS
PAGE
SAFETY CONSIDERATIONS 1........................
INSTALLATION 2--9................................
Step 1 -- Complete Pre--Installation Checks 2............
Step 2 -- Rig and Mount Unit 2......................
Step 3 -- Complete Refrigerant Piping Connections 4.....
Step 4 -- Make Electrical Connections 7................
START--UP 10.......................................
SERVICE 10........................................
MAINTENANCE 14..................................
TROUBLESHOOTING 14.............................
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service, maintenance,
or use can cause explosion, fire, electrical shock, or other
conditions which may cause death, personal injury, or property
damage. Consult a qualified installer, service agency, or your
distributor or branch for information or assistance. The qualified
installer or agency must use factory--authorized kits or accessories
when modifying this product. Refer to the individual instructions
packaged with the kits or accessories when installing.
Follow all safety codes. Wear safety glasses, protective clothing,
and work gloves. Use quenching cloth for brazing operations.
Have fire extinguisher available. Read these instructions
thoroughly and follow all warnings or cautions included in
literature and attached to the unit. Consult local building codes and
National Electrical Code (NEC) for special requirements.
Recognize safety information. This is the safety--alert symbol !
!
When you see this symbol on the unit and in instructions or
manuals, be alert to the potential for personal injury. Understand
these signal words; DANGER, WARNING, and CAUTION. These
words are used with the safety--alert symbol. DANGER identifies
the most serious hazards which will result in severe personal injury
or death. WARNING signifies hazards which could result in
personal injury or death. CAUTION is used to identify unsafe
practices which would result in minor personal injury or product
and property damage. NOTE is used to highlight suggestions
which will result in enhanced installation, reliability, or operation.
!WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing, modifying, or servicing system, main
electrical disconnect switch must be in the OFF
position. There may be more than 1 disconnect switch.
Lock out and tag switch with a suitable warning label.

2
INSTALLATION
!WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could result in personal injury
or equipment damage.
Puron refrigerant systems operate at higher pressures than
standard R--22 systems. Do not use R--22 service
equipment or components on Puron refrigerant equipment.
PERSONAL INJURY AND EQUIPMENT DAMAGE
HAZARD
Failure to follow this caution may result in personal injury
and / or equipment damage.
DO NOT operate the unit without a filter or with grille
removed.
CAUTION
!
Step 1 —Complete Pre--Installation Checks
Unpack Unit
Move the unit to final location. Remove unit from carton,
being careful not to damage service valves and grilles.
Inspect Shipment
File a claim with the shipping company if shipment is damaged or
incomplete. Check the unit nameplates to ensure units match job
requirements.
Consider System Requirements
Consult local building codes and NEC for special installation
requirements.
Allow sufficient space for airflow clearance, wiring, refrigerant
piping, and servicing unit. See Fig. 2.
Locate unit so that condenser airflow is unrestricted on both sides.
Refer to Fig. 2.
Unit may be mounted on a level pad directly on base legs or
mounted on raised pads at support points. See Fig. 2 for center of
gravity.
Matching the Condensing Unit to an Indoor Unit
The 38HDR018--060 ducted condensing units can be matched to
corresponding indoor units. The 38HDR unit can be matched with
under--ceiling and residential fan coils and evaporator coils. Refer
to separate indoor unit literature for more information.
Step 2 —RIG AND MOUNT UNIT
Mounting on Ground
Mount unit on a solid, level concrete pad. Position unit so water or
ice from roof does not fall directly onto unit. Accessory stacking
kits can be used when units are to be stacked. See installation
instructions provided with the accessory kit. Use field--provided
snow stand or ice rack where prolonged subfreezing temperatures
or heavy snow occurs.
If conditions or local codes require unit be fastened to a pad, 6
field--supplied tiedown bolts should be used and fastened through
slots provided in unit mounting feet.
Mounting on Roof
Mount unit on a level platform or frame at least 6 in. (152.4 mm)
above roof surface. Isolate unit and tubing from structure.
38HDR

3
(FIELD PROVIDED AND INSTALLED)
NOTE: Dimensions shown in feet--inches. Dimensions in ( ) are millimeters.
UNIT MODELS CHASSIS
SIZE
(Reference)
ABC D E FG H JKL NP
38HDR
Unit Size
018 02’--1
1
/
8”
3’--0
15
/
16”
1’--2
9
/
16”
1’--4” 1’--11
7
/
16”
1’--5
3
/
16”
1’--5
1
/
8”
1’--10” 1’--1” 0’--6
5
/
8”
0’--11
1
/
4”
0’--2
15
/
16”
0’--6”
(638.2) (938.2) (369.9) (406.4) (595.3) (436.6) (435) (559.1) (330.2) (168.3) (285.8) (75) (152.4)
024 0.6 2’--7
1
/
8”
3’--0
15
/
16”
1’--2
9
/
16”
1’--4” 1’--11
7
/
16”
1’--5
3
/
16”
1’--11
1
/
8”
2 ’ -- 4 ” 1 ’ -- 2 ” 0 ’ -- 6
3
/
4”
0’--11
5
/
8”
0’--2
15
/
16”
0’--6”
(790.6) (938.2) (369.9) (406.4) (595.3) (436.6) (587.4) (711.5) (355.6) (171.5) (295.3) (75) (152.4)
030, 036 1.0 3’--1
3
/
16”
1’--5
1
/
16”
1’--6
7
/
16”
2’--6
1
/
2”
1’--7
5
/
8”
2’--5
3
/
16”
2’--10
1
/
16”
1’--1
11
/
16”
0’--8
1
/
8”
1’--3
7
/
8”
0’--3
7
/
16”
0’--6
1
/
2”
(944.6) (1131.9) (433.4) (468.3) (774.7) (498.5) (741) (865.5) (347.7) (206.4) (403.2) (88) (165.4)
048, 060 1.6 3’--7
3
/
16”
1’--5
1
/
16”
1’--6
7
/
16”
2’--6
1
/
2”
1’--7
5
/
8”
2’--11 /
13/16”
3’--4
1
/
16”
1’--2
1
/
2”
0’--8
1
/
2”
1’--6
7
/
8”
0’--3
7
/
16”
0’--6
1
/
2”
(1097) (1131.9) (433.4) (468.3) (774.7) (498.5) (893.4) (1017.9) (354.2) (215.9) (479.4) (88) (165.4)
UNIT SIZE M OPERATING WT
in. mm lb kg
38HDR
018
5
/
8
15.88 166 75.8
024
5
/
8
15.88 176 79.8
030
3
/
4
19.05 187 84.8
036
3
/
4
19.05 250 113.4
048
7
/
8
22.22 278 126.1
060
7
/
8
22.22 306 138.8
NOTES: 1. Required clearances: with coil facing wall, allow 6 in. minimum clearance
on coil side and coil end, and 3 feet minimum clearance on compressor end and fan side. With fan facing wall, allow 8 in. minimum clearance on fan side and coil end, and 3 feet minimum clearance on compressor end and coil side. With multi--unit application, arrange units so discharge of one does not enter inlet of another.
2. Dimensions in parenthesis are in millimeters. 3. Center of Gravity .
UNIT SIZE
MINIMUM MOUNTING PAD
DIMENSIONS
Support Feet
ft--in. mm
CHASSIS SIZES 0 & .6 1 -- 11 x3 --6 584.2 x 1066.8
CHASSIS SIZES 1 & 1.6 2--0x4--2 609.6 x 1270
3’ -- 8
9/16”
3’ -- 8
9/16”
Fig. 2 --- 38HDR Unit Dimensions
38HDR

4
Rigging
PERSONAL INJURY AND/OR EQUIPMENT
DAMAGE HAZARD
Failure to follow this caution may result in personal injury
and/or equipment damage.
Be sure unit panels are securely in place prior to rigging.
CAUTION
!
Keep the unit upright and lift unit using a sling. Use cardboard or
padding under the sling, and spreader bars to prevent sling damage
to the unit. See Fig. 3. See Fig. 2 for center of gravity reference.
Install the unit so that the coil does not face into prevailing winds.
If this is not possible and constant winds above 25 mph are
expected, use accessory wind baffle. See installation instructions
provided with the accessory kit.
NOTE: Accessory wind baffles should be used on all units with
accessory low ambient temperature control.
Field--fabricated snow or ice stands may be used to raise unit when
operation will be required during winter months. Units may also be
wall mounted using the accessory wall mounting kit.
A07396
Fig. 3 --- Lifting Unit with Sling
Step 3 —COMPLETE REFRIGERANT PIPING CONNEC-
TIONS
Outdoor units may be connected to indoor units using
field--supplied tubing of refrigerant grade and condition. See Table
1 for correct line sizes. Do not use less than 10 ft (3.05 m) of
interconnecting tubing.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
If any section of pipe is buried, there must be a 6 in. (152.4
mm) vertical rise to the valve connections on the outdoor
unit. If more than the recommended length is buried,
refrigerant may migrate to cooler, buried section during
extended periods of system shutdown. This causes
refrigerant slugging and could possibly damage the
compressor at start--up.
When more than 80 ft (24.38 m) of interconnecting tubing and
more than 20 ft (6.10 m) of vertical lift is used, consult the
residential Long Line Application Guide for required accessories.
If either refrigerant tubing or indoor coil is exposed to the
atmosphere, the system must be evacuated following good
refrigeration practices.
Run refrigerant tubes as directly as possible, avoiding unnecessary
turns and bends. Suspend refrigerant tubes so they do not damage
insulation on vapor tube and do not transmit vibration to structure.
Also, when passing refrigerant tubes through a wall, seal the
opening so that vibration is not transmitted to structure. Leave
some slack in refrigerant tubes between structure and outdoor unit
to absorb vibration. Refer to separate indoor unit installation
instructions for additional information.
Expansion Device
A hard shutoff, thermostatic expansion valve (TXV) is required at
the indoor section of the system for proper operation of these
products. If the indoor section of the system is not equipped with a
hard shutoff TXV, refer to Spec Sheet for the correct TXV kit to be
installed. Follow the instructions in the kit for proper installation.
38HDR

5
Filter Drier
The filter drier must be replaced whenever the refrigeration system
is exposed to the atmosphere.
Refer to Fig. 4 and install filter drier as follows:
1. Braze 5--in. (127 mm) liquid tube to the indoor coil.
2. Wrap filter drier with damp cloth.
3. Braze filter drier to above 5--in. (127 mm) liquid tube.
Flow arrow must point towards indoor coil.
4. Connect and braze liquid refrigerant tube to the filter drier.
A05178
Fig. 4 --- Filter Drier Components
Only use factory specified liquid--line filter driers with rated
working pressures less than 600 psig.
NOTE: Do not install a suction--line filter drier in liquid line.
Make Piping Sweat Connections
Remove plastic caps from liquid and suction service valves. Use
refrigerant grade tubing. Service valves are closed from the factory
and are ready for brazing. After wrapping the service valve with a
wet cloth, the tubing set can be brazed to the service valve using
either silver bearing or non--silver bearing brazing material.
Consult local code requirements. Refrigerant tubing and the indoor
coil are now ready for leak testing.
NOTE: Unit is shipped with Puronrrefrigerant factory charge
indicated on nameplate.
Pass nitrogen or other inert gas through piping while brazing to
prevent formation of copper oxide.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
To prevent damage to unit or service valves observe the
following:
SUse a brazing shield.
SWrap service valves with wet cloth or use a heat sink
material.
Provide Safety Relief
A fusible plug is located in unit suction line; do not cap this plug.
If local code requires additional safety devices, install as directed.
38HDR

6
Table 1—38HDR018--060 Physical Data
UNIT 38HDR 018 024 030 036 048 060
NOMINAL CAPACITY Tons 1.5 2.0 2.5 3.0 4.0 5.0
OPERATING WEIGHT lb (kg) 166 (75.30) 176 (79.83) 250 (113.4) 250 (113.4) 278 (126.10) 306 (138.80)
REFRIGERANT TYPE Puronr(R---410A)
METERING DEVICE TXV
CHARGE lb (kg)* 6.3 (2.86) 6.5 (2.95) 10.0 (4.54) 10.0 (4.54) 12.0 (5.44) 12.0 (5.44)
COMPRESSOR
Type Scroll
O i l C h a r g e ( P O E --- o z ) 25.0 25.0 25.0 25.0 42.0 42.0
Crankcase Heater (watts) — — 40 40 40 40
OUTDOOR FAN
Rpm/Cfm 840/1720 840/1720 850/3900 850/3900 850/3900 850/3900
Diameter in. (mm) 18 (457.2) 24 (609.6)
No. Blades 3
Motor (hp) 1/8 1/4
OUTDOOR COIL
Face Area (sq ft) 5.8 7.3 12.1 12.1 14.1 14.1
No. Rows 2 3 2 2 3 3
FPI 20 20 20 20 20 20
HIGH PRESSURE SWITCH
C u t --- I n p s i g
Cutout psig
420 ±25
650 ±10
LOW PRESSURE SWITCH
Low Cutout psig
Low Cut---in psig
20 ±5
45 ±25
REFRIGERANT LINES
Connection Type Sweat
Liquid Line (in.) OD 3/8 3/8 3/8 3/8 3/8 3/8
Vapor Line (in.) OD 5/8 5/8 3/4 3/4 7/8 7/8†
Max Length ft. (m) 200 (60.96)
Max Lift ft. (m) 65 (19.81)
Max Drop ft. (m) 150 (45.72)
CONTROLS
Fusible Plug _F(_C) 210 (98.89)
Control Voltage}24 vac
System Voltage 208/230 v 208/230 v 208/230 v 208/230 v, Single and 3 Phase, 460 v, 3 Phase
FINISH Gray
* Unit shipped with full factory charge. See ARI (Air Conditioning and Refrigeration Institute) capacity table for proper charge and piston for each fan coil type.
{Valve connection size is 7/8 inch. Recommended line size is 1---1/8 inches.
}24 v and a minimum of 40 va is provided in the fan coil unit.
FPI --- Fins Per Inch
POE --- P o l y o l E s t e r
38HDR

7
Step 4 —Make Electrical connections
!WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
The unit cabinet must have an uninterrupted or unbroken
ground to minimize personal injury if an electrical fault
should occur. The ground may consist of electrical wire or
metal conduit when installed in accordance with existing
electrical codes.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Unit failure as a result of operation on improper line voltage
or excessive phase imbalance constitutes abuse and may
cause damage to electrical components. Such operation
would void any applicable Carrier warranty.
!WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before performing service or maintenance, be sure indoor
unit main power switch is turned OFF and indoor blower
has stopped.
Control Circuit Wiring
Control voltage is 24 v (40 va minimum). See Fig. 5 and unit label
diagram for field--supplied wiring details. Route control wire
through opening in unit side panel to connection in unit control
box.
A07398
Fig. 5 --- 38HDR Typical Control Circuit Connections
NOTE: Use No. 18 AWG color----coded, insulated (35_C
minimum) wire. If thermostat is located more than 100 ft (30.48
m). from unit, as measured along the control voltage wires, use No.
16 AWG color--coded wire to avoid excessive voltage drop.
NOTE: All wiring must conform to NEC and local codes.
NOTE: Operating unit on improper line voltage constitutes abuse
and could affect Carrier warranty. See Table 2. Do not install unit
in a system where voltage may fluctuate above or below
permissible limits.
See Table 2 for recommended fuse sizes. When making electrical
connections, provide clearance at the unit for refrigerant piping
connections.
NOTE: The 38HDR units use the control transformer supplied
with the matched indoor unit.
Power Wiring
Unit is factory wired for voltage shown on nameplate. Provide
adequate, fused disconnect switch within sight from unit, readily
accessible, but out of reach of children. Provision for locking the
switch open (off) is advisable to prevent power from being turned
on while unit is being serviced.
Disconnect switch, fuses, and field wiring must comply with the
NEC and local code requirements. Use copper wire only between
the disconnect switch and unit. Use minimum 60 C wire for the
field power connection.
Route power wires through the opening in unit side panel and
connect in the unit control box as shown on the unit label diagram
and Fig. 6. Unit must be grounded.
Connections to Duct Free Fan Coil Units
The 38HDR units are designed for easy match--up to 40QA duct free
fan coils. This unit provides 24 v power for the outdoor unit from the
fan coil.Connectthe Y and C terminals of the indoor unit to the Yand
Cterminals.
38HDR

8
Table 2—38HDR Electrical Data
38HDR
UNIT
SIZE
V --- P H --- H z
VOLTAGE
RANGE*
COMPRESSOR OUTDOOR FAN MOTOR MIN
CKT
AMPS
FUSE/BKR
AMPS
RLA LRA FLA NEC
Hp
kw
Out
Min Max
018 208/230---1---60 187 253 9.0 48.0 0.80 0.125 0.09 12.1 20
024 208/230---1---60 187 253 12.8 58.3 0.80 0.125 0.09 16.8 25
030 208/230---1---60 187 253 14.1 73.0 1.45 0.25 0.19 19.1 30
036
208/230---1---60 187 253 14.1 77.0 1.45 0.25 0.19 19.1 30
208/230---3---60 187 253 9.0 71.0 1.45 0.25 0.19 12.7 20
4 6 0 --- 3 --- 6 0 414 506 5.6 38.0 0.80 0.25 0.19 7.8 15
048
208/230---1---60 187 253 21.8 117.0 1.45 0.25 0.19 28.7 50
208/230---3---60 187 253 13.7 83.1 1.45 0.25 0.19 18.6 30
4 6 0 --- 3 --- 6 0 414 506 6.2 41.0 0.80 0.25 0.19 8.6 15
060
208/230---1---60 187 253 26.4 134.0 1.45 0.25 0.19 34.5 60
208/230---3---60 187 253 16.0 110.0 1.45 0.25 0.19 21.5 35
4 6 0 --- 3 --- 6 0 414 506 7.8 52.0 0.80 0.25 0.19 10.6 15
LEGEND:
FLA --- F u l l L o a d A m p s
LRA --- L o c k e d R o t o r A m p s
NEC --- National Electrical Code
RLA ---RatedLoadAmps(compressor)
* Permissible limits of the voltage range at which the unit will operate
satisfactorily
NOTES:
1. Control circuit is 24---V on all units and requires external power
source. Copper wire must be used from service disconnect to unit.
2. All motors/compressors contain internal overload protection.
3. In compliance with NEC (U.S.A. Standard) requirements for multi-
motor and combination load equipment (refer to NEC Articles 430
and 440), the overcurrent protective device for the unit shall be fuse
or breaker.
4. Motor RLA values are established in accordance with UL (Underwrit-
ers’ Laboratories) Standard 465 (U.S.A. Standard).
5. 38HDR018---030 units are only available in single---phase voltage.
6. Unbalanced 3---Phase Supply Voltage
Never operate a motor where a phase imbalance in supply voltage is
greater than 2%. Use the following formula to determine the percent-
age of voltage imbalance:
= 100 X max voltage deviation from average voltage
average
EXAMPLE: S u p p l y v o l t a g e i s 4 6 0 --- 3 --- 6 0
AB = 452v
BC = 464v
AC = 455v
Average Voltage = 452 + 464 + 455
3
=1371
3
=457
Determine maximum deviation from average voltage:
(AB) 457---452 = 5v
(BC) 464 ---457 = 7v
(AC) 457---455 = 2v
Maximum deviation is 7v.
Determinepercentageofvoltageimbalance
% of voltage imbalance = 100 x 7
57
=1.53%
This amount of phase imbalance is satisfactory as it is below the maximum
allowable of 2%.
IMPORTANT: Contact your local electric utility company immediately if the
supply voltage phase imbalance is more than 2%.
38HDR

9
LEGEND
NOTES:
1. Compressor and fan motors are thermally protected.
2. Wire in accordance with National Electrical Code (NEC) and local codes. Replace
any original wires with 90° C wire or its equivalent.
3. The CLO locks out the COMP to prevent short cycling on COMP overloads and
safety devices. Before replacing CLO check these devices.
4. If indoor section has a transformer with a grounded secondary, connect the
grounded side to “C” on the low voltage board.
5. Use minimum 60° C wire for field power wiring.
6. Crankcase heater and thermostat used on selected models only.
C—Contactor, Compressor
CAP — Capacitor
CCHT — Crankcase Heater Thermostat
CH — Crankcase Heater
COMP — Compressor Motor
EQUIP — Equipment
GND — Ground
HPS — High-Pressure Switch
LPS — Low-Pressure Switch
OFM — Outdoor-Fan Motor
OL — Overload
TB — Terminal Board
Splice (Field)
Terminal (Marked)
Terminal (Unmarked)
Terminal Block
Splice
Factory Wiring
Field Control Wiring
Field Power Wiring
38HDR OPERATION SEQUENCE
CALL FOR COOLING:
1. Control voltage from transformer to thermostat (24 v).
2. At thermostat 24 v is switched to “G” and “Y.”
3. 24 v from thermostat “G” energizes fan relay at indoor fan coil and indoor-fan motor runs.
4. 24 v from thermostat “Y” energizes the contactor coil at the outdoor unit.
Compressor and outdoor-fan motor run.
6. If the internal protector of the compressor, HPS, or LPS open, the 24 v to the contactor coil will be inter-
rupted, and compressor and outdoor fan motor will stop.
A07535
Fig. 6 --- 38HDR018--060 Typical Wiring Schematic
38HDR

10
START--UP
Step 1 —Preliminary Checks
1. Check that all internal wiring connections are tight and that
all barriers, covers, and panels are in place.
2. Field electrical power source must agree with unit name-
plate rating.
3. All service valves must be open.
4. Belly--band crankcase heater must be tight on compressor
crankcase for those units with belly--band heaters.
Step 2 —Leak Test
Field piping and fan coil must be leak tested by pressure method.
Use Puronrrefrigerant at approximately 25 psig backed up with an
inert gas to a total pressure not to exceed 245 psig.
Step 3 —Evacuate and Dehydrate
Field piping and fan coil must be evacuated and dehydrated.
Step 4 —Charge System
Release charge into system by opening (backseating) liquid and
suction line service valves.
Step 5 —To Start Unit
Be sure that the field disconnect is closed. Set room thermostat
below ambient temperature. Operate unit for 15 minutes, then
check system refrigerant charge. See Refrigerant Charging section
on page 12.
NOTE: When using in conjunction with 40QA fan coils, refer to
start--up instructions included with fan coil for correct start--up
procedures.
SERVICE
!WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing, modifying, or servicing system, main
electrical disconnect switch must be in the OFF
position. There may be more than 1 disconnect switch.
Lock out and tag switch with a suitable warning label.
Outdoor Fan
A reinforced wire mount holds the outdoor fan assembly in
position. See Fig. 7 for proper mounting position.
38HDR Unit Size, in. (mm)
018,024 030,036 048,060
0.433 (11.00) 0 0
A07401
Fig. 7 --- Condenser Fan Mounting Positions
High--Pressure Relief Valve
The high--pressure relief valve is located in the compressor. The
relief valve opens at a pressure differential of approximately 550 to
625 ±50 psig between suction (low side) and discharge (high side)
to allow pressure equalization.
Internal Current and Temperature Sensitive Overload
The control resets automatically when internal compressor motor
temperature drops to a safe level (overloads may require up to 45
minutes to reset). When an internal overload is suspected of being
open, check by using an ohmmeter or continuity tester.
Pumpdown Procedure
The system may be pumped down in order to make repairs on the
low side without losing complete refrigerant charge.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Never open system to atmosphere while it is under a
vacuum.
When system must be opened for service, recover refrigerant, break
vacuum with dry nitrogen before opening system.
1. Attach pressure gage to suction service valve gage port.
2. Frontseat the liquid/mixed phase line valve.
3. Start unit and run until suction pressure reaches 20 psig.
4. Shut unit off and frontseat suction valve.
5. De--pressurize low side of unit and recover refrigerant fol-
lowing accepted practices.
38HDR