Carrier 38AF Series User manual

Installation Manual

Product Development Dept.
07/2005
2
CONTENTS PAGE
Safety considerations…………………… 2
Installation……...……………………...…..
Step 1 – complete pre-installation checks.. 3
Step 2 – rig and mount the unit…………… 6
Step 3 – complete electrical connections.. 7
Pre-start-up………………………...……….
Evacuate and dehydrate………………….. 8
Leak test…………………………………….. 8
Turn on crankcase heaters……………… 8
Add preliminary charge…………………… 8
Start – up…………………………………...
To start unit………………………………… 8
Oil charge…………………………………… 8
Service………………...……………………
Capacity control…………………………… 9
Control set point & Pressure differential… 9
Time guard£ll circuit……………………… 9
Crankcase heater………………………… 9
Outdoor fan………………………………… 9
Lubrication………………..………………… 10
Cleaning coils……………………………… 10
Troubleshooting….……………..………… 11-12
Wiring diagram 13-16
Start-up checklist………………………… 17
SAFETY
CONSIDERATIONS
Installing, starting up, and
servicing air-conditioning
equipment can be
hazardous due to system
pressures, electrical
components, and equipment
location (roofs, elevated
structures, etc.)
Only trained, qualified
installers and service
mechanics should install,
start-up, and service this
equipment (Fig.1)
Untrained personnel can
perform basic maintenance
functions such as cleaning
coils. Trained service
personnel should perform all
other operations.
When working on the
equipment, observe
precautions in the literature
and on tags, stickers, and
labels attached to the
equipment.
Follow all safety codes.
Wear safety glasses and
work gloves. Keep
quenching cloth and fire
extinguisher nearby when
brazing. Use care in
handling, rigging and setting
bulky equipment.
7
8
9
9
9
9
9
9
10
10
10
10
10
11
11
12
14
17

POWER WIRING
Description Air Cooled Condensing Unit
Model 38AE010 38AE015 38AE020 38AE025 38AE030 38AE040 38AE050 38AE060
Nominal Capacity* BTU/Hr(KW) 120,000(35) 156,000(45) 200,000(58) 280,000(82) 320,000(93) 400,000(117) 550,000(161) 615,000(180)
Operating Weight lb(kg.) 809(367) 825(374) 1,155(524) 1,286(583) 1,367(620) 1,435(651) 1,950(885) 2,125(966)
Compressor Semi-Hermetic
Quantity...Model 1...06D328 1...06D537 1...06E250 1...06E266 1...06E275 1...06E299 2...06E266 2...06E275
Lubricating Oil gal. 1.0 1.0 1.7 2.4 2.4 3.2 2...2.4 2...2.4
Capacity Steps (by unload) % 0/66/100 0/66/100 0/50/100 0/50/100 0/66/100 0/66/100 0/25/50/75/10 0/33/50/83/100
Refrigerant R-22
Operating Charge** lb(kg.) 22(10.1) 23(10.5) 28(12.7) 30(13.6) 43(19.5) 65(29.5) 2...30(2...13.6) 2...43(2...19.5)
Condenser Fans Propeller, Direct Drive
Quantity...Diameter in. 2...24 2...24 2...32 2...32 2...32 2...32 3...32 3...32
Nominal Air Flow CFM 7,400 7,400 20,000 21,200 23,200 23,200 33,000 33,000
Fan Motor V/Ph/Hz 220/1/50(1/2 HP) 220/1/50(1 HP) 380/3/50(2 HP) 380/3/50(2 HP)
Power Consumption Watt 1,100 2,200 2,700 4,030
Condenser Coil Aluminium Fin Copper Tube
Row...Fin/Inch 3...15 3...15 1.5...15 3...15 3...15 3...15 3...15 3...15
Face Area sq.ft. 22.72 22.72 42.94 42.94 54.00 54.00 73.23 73.23
Electrical Controls Time Guard Control Module
High-Pressure Switch Psig 395/275
Low-Pressure Switch Psig 60/30 (Auto Reset)
Oil-Pressure Switch Psig 6/14
Starter D.O.L. Part Winding
Piping Connections Suction in. 1 3/8 1 3/8 1 5/8 1 5/8 2 1/8 2 1/8 2...1 5/8 2...2 1/8
Liquid in. 5/8 5/8 7/8 7/8 7/8 7/8 2...7/8 2...7/8
* RATING CONDITION: OUTDOOR AMBIENT TEMPERATURE 95 ÌF, SATURATED SUCTION TEMPERATURE 45 ÌF
** UNIT SUPPLIED FROM FACTORY ONLY PRE-CHARGE
* RATING CONDITION: OUTDOORAMBIENT TEMPERATURE 95 F, SATURATED SUCTION TEMPERATURE 45 F
** UNIT SUPPLIED FROM FACTORY ONLYPRE-CHARGE
Air Cooled Condensing Unit
Product Model 38AE020 38AE025 38AE030 38AE040 38AE050 38AE060
W 58,900 82,300 94,000 118,100 160,600 177,200
Btu/hr. 201,000 281,000 321,000 403,000 548,000 604,900
PowerConsumption W 19,370 26,360 28,360 39,860 52,450 58,050
Power Supply V/Ph./Hz 380/3/50
Operating Current Amp. 44.05 54.84 59.38 85.12 108.68 120.42
Model 06E2250611 06E2265611 06E627506 06E6299681 06E2265611 06E627506
Type Semi-Hermetic Reciprocating
Quantity 111122
RLA 36 48.8 53.4 79.1 2 x48.8 2 x53.4
LRA 173 223 253 345 2 x 223 2 x253
Type Copper Tube / Aluminium Fin
Row 1.533333
Fin / Inch 15 15 15 15 15 15
Face Area sq.ft. 42.94 42.94 54.00 54.00 73.23 73.23
Power Supply V/Ph./Hz 220/1/50 380/3/50
PowerOutput Hp122222
RLA Amp. 2 x 4.31 2 x 3.30 2 x3.30 2 x 3.30 3 x 4.95 3 x 4.95
Power Input W 2,200 2,700 4,030
FanType Propeller
Drive Type Direct
FanDiameter inch 28 27 30 30 27 30
Quantity 2 22233
Nominal Air Flow CFM 20,000 21,200 23,200 23,200 33,000 33,000
Hi-Pressure Switch psig 395 / 275 (Cut out / Cut in) - Auto Restart type
Low-Pressure Switch psig 30 / 60 (Cut out / Cut in) - Auto Restart type
Oil-Pressure Switch psig 6 / 14 (Cut out / Cut in) - Auto Restart type
CapacityStep Control(By Unload) % 0/50/100 0/66/100 0/66/100 0/66/100 0/33/50/83/100 0/33/50/83/100
Starter PartWinding
Electrical Controls Time Guard ControlModule
Type R-22
Pre-Charging from Facto
r
kg. 0.30
Operation Charging kg. 12.70 13.60 19.50 29.50 2 x 13.6 2 x 19.5
Liquid inch 7/8 7/8 7/8 7/8 2…..7/8 2…..7/8
Suction inch 1...5/8 1...5/8 2...1/8 2...1/8 2…..1 5/8 2…..2 1/8
Weight lb(kg.) 1,155 (524) 1,286 (583) 1,367 (620) 1,435 (651) 1,950 (885) 2,125 (966)
Description
NominalCooling Capacity
Refrigerant
Piping Connections
Safety Device
FanMotor
Coil
Compressor
38AE010-015
Remark: RLA :Rated Load Amps. LRA :LockedRotor Amps.Cabletype :THW
Typeofconductor is installed :Insulatedsingle corecablesupto3 lines.Or
Insulatedsheathed cablesup to3axes ina pipe intheairinapipe buried inthewallplaster.orina pipeintheceiling
Min Max RLA LRA QTY RLA Power
Wire(mm.2) Ground Wire (mm.2) Field CB (AT)
38AE020 380V/3Ph/50Hz 342 415 36.2 173 2 4.31 25 6 70
38AE025 380V/3Ph/50Hz 342 415 48.8 223 2 3.30 35 10 90
38AE030 380V/3Ph/50Hz 342 415 53.4 253 2 3.30 35 10 90
38AE040 380V/3Ph/50Hz 342 415 79.1 345 2 3.3 95 16 150
38AE050 380V/3Ph/50Hz 342 415 2…..48.8 2…..223 3 4.95 95 16 175
38AE060 380V/3Ph/50Hz 342 415 2…..53.4 2…..253 3 4.95 120 16 200
Recommended
Unit Model Power Supply
Voltage Range Compressor Fan Motor

* RATING CONDITION: OUTDOOR AMBIENT TEMPERATURE 95 F, SATURATED SUCTION TEMPERATURE 45 F
** UNITSUPPLIED FROM FACTORY ONLY ONRY NITROGEN
38AF020 38AF025 38AF030 38AF040 38AF050 38AF060
58,000 82,000 93,000 117,000 161,000 180,000
200,000 280,000 320,000 400,000 550,000 615,000
050,85054,25068,93063,82063,62073,91noitpmusnoC rewoP
Power Supply
24.02186.80121.5883.9548.4550.44tnerruC gnit
arepO
605726E601165622E601869926E60605726E601165622E601160522E60ledoM
Type
221111ytitnauQ
4.35 x 28.84 x 21.
974.358.8463ALR
352 x 2322 x 2543352322371ARL
1.lagliO gnitacirbuL .7 2.4 2.4 3.2 2…..2.4 2…..2.4
Type
333225.1woR
51515151
5151hcnI / niF
32
.3732.3700.4500.4549.2449.24.tf.qsaerA ecaF
05/1/022zH/.hP/VylppuS rewoP
222221pHtuptuO rewoP
59.4 x 359
.4 x 303.3 x 203.3 x 203.3 x 213.4 x 2.pmAALR
002,2WtupnI rewoP
Fan Type
Drive Type
037203037282hcniretemaiD naF
332222yti
tnauQ
000,33000,33002,32002,32002,12000,02MFCwolF riA lanimoN
Hi-Pressure Switch psig
Low-Pressure Switch psig
Oil-Pressure Switch psig
001/38/05/33/0001/38/05/33/0001/66/00
01/66
/0001/66/0001/05/0%)daolnU yB( lortnoC petS yticapaC
Starter
Electrical Controls
Type
Pre-Charging from Factory kg.
5.91 x 26.31 x 205.9205.9106.3107.21.gkgn
igrahC noitarepO
8/7..…28/7..…28/78/78/78/7hcnidiuqiL
8/1 2..…28/5 1..…28/1…28/1…28/5…18/5…1hcninoitcuS
)669( 521,2)588( 059,1)156( 534,1)026( 763,1)385( 682,1)425( 551,1).gk(bIthgieW
Refrigerant
R407C
Nitro
g
en
Piping Connections
Safety Device
395 / 275
(
Cut out / Cut in
)
- Auto Restart t
yp
e
30 / 60
(
Cut out / Cut in
)
- Auto Restart t
yp
e
6 / 14
(
Cut out / Cut in
)
- Auto Restart t
yp
e
Part Windin
g
Time Guard Control Module
Compressor
Coil
Co
pp
er Tube / Aluminium Fin
Fan Motor
380/3/50
030,4007,2
Pro
p
eller
Direct
w
05/3/083zH/.hP/V
Am
p
.
Semi-Hermetic Reci
p
rocatin
g
Descri
p
tion Air Cooled Condensin
g
Unit
Product Model
Nominal Cooling Capacity w
Btu/hr.
.spmArotoRdekcoL:ARL.spmAdaoLdetaR:ALR:krameR Cable type : THW
Type of conductor is installed : Insulated single core cables up to 3 lines. Or
Insulated sheathed cables up to 3 axes ina pipe inthe air in a pipe buried inthe wallplaster. or in a pipe inthe ceiling
Min Max RLA LRA QTY RLA Power
Wire(mm.2)
Ground Wire
(mm.2) Field CB (AT)
38AF020 380V/3Ph/50Hz 342 415 36.2 173 2 4.31 25 6 70
38AF025 380V/3Ph/50Hz 342 415 48.8 223 2 3.30 35 10 90
38AF030 380V/3Ph/50Hz 342 415 53.4 253 2 3.30 35 10 90
38AF040 380V/3Ph/50Hz 342 415 79.1 345 2 3.3 95 16 150
38AF050 380V/3Ph/50Hz 342 415 2…..48.8 2…..223 3 4.95 95 16 175
38AF060 380V/3Ph/50Hz 342 415 2…..53.4 2…..253 3 4.95 120 16 200
Recommended
Unit Model Power Supply
Voltage Range Compressor Fan Motor
POWER WIRING

38AE020-040 / 38AF020-040
38AE050-060 / 38AF050-060
Dimension

Product Development Dept.
07/2005
6
Step 2 – Rig and mount the Unit
RIGGING – These units are designed for
overhead rigging only. For this purpose, the
transverse base channels extend beyond the
sides of the unit, with holes provided in the end
plates to attach cables or hooks. Rig with top
skid packaging assembly in place to prevent
unit damage by the rigging cable. As further
protection for the coil faces, plywood sheets
can be placed against the sides of the unit,
behind the cables. Run the horizontal is not
less than 45 degrees. Raise and set the unit
down carefully.
If it is necessary to roll the unit into position,
mount the unit on longitudinal rails, using a
minimum of 3 rollers. Apply force to the rails,
not the unit. If the unit is to be skidded into
position, place it on a large pad and drag it by
the pad. Don not applies any force to the unit.
Rise from above to lift unit from the rails or pad
when unit is in final position.
COMPRESSOR MOUNTING –As shipped, the
compressor is held tightly in place by self-
locking bolts.
Before starting unit, loosen self-locking
bolts until the snubbed washer can be
moved sideways with finger pressure. Do
not remove shipping bolts. See Fig.3.
Fig. 3 — Compressor Mounting
INSTALL FILTER DRIER (S) AND MOISTURE INDICATOR (S) — Every unit should have a filter drier
and liquid-moisture indicator (sight glass). In some applications, depending on space and convenience
requirements, it may be desirable to install 2 filter dryers and sight glasses. One filter drier and sight
glass may be installed at Alocations in Fig. 4. Or, 2 filter dryers and sight glasses may be installed at B
locations.
Select the filter drier for maximum unit capacity and minimum pressure drop. Complete the refrigerant
piping from indoor unit to outdoor unit before opening the liquid and suction lines at the outdoor unit.
Fig.4 - Location of Slight Glass
7
Be sure unit panels are securely in place prior to
rigging.

Product Development Dept.
07/2005
7
INSTALL LIQUID LINE SOLENOID VALVE —
SOLENOID DROP—It is recommended that a
solenoid valve be placed in the main liquid line
(see Fig. 4) between condensing unit (38AE)
and fan coil (40RR). (A liquid line solenoid
valve is required when the liquids line length
exceeds 100-ft [30.5 m] or when the
condensing unit is connected to the chiller
barrel in a built-up chiller system.) This valve
prevents refrigerant migration (which causes oil
dilution) to the compressor during the off cycle
at low outdoors-ambient temperatures. The
solenoid should be wired in parallel with the
compressor contractor coil. This means of
electrical control is referred to as solenoid drop
control.
INSTALLLIQUID LINE SOLENOIDVALVE
(OPTIONAL) CAPACITY CONTROLS — If 2-
step cooling is desired, place a solenoid valve
in the location shown in Fig. 4.
MAKE PIPING CONNECTIONS —Do not remove run around loop from suction and liquid line stubs in
the compressor compartment until piping connections are ready tube made. Pass nitrogen or other inert
gas through piping while brazing to prevent formation of copper oxide.
Install field supplied thermostatic expansion valve(s) in indoor
section. If 2 thermostatic expansion valves are installed for 2-
step cooling, install field-supplied liquid line solenoid valve
ahead of the second expansion valve.
PROVIDE SAFETY RELIEF — A fusible plug is located on
the compressor crankcase or in the liquid line (Fig. 5). Do not
cap this plug. If local code requires additional safety devices,
install them as directed.
Fig.5 - Location of Fusible Plug (38AE)
Step 3 – Complete Electrical Connections
POWER WIRING –Unit is factory wired for voltage shown on nameplate. Provide adequate fused
disconnect switch within sight from unit and readily accessible from unit , but out of the reach of children.
Locks witch open (off) to prevent power from being turned on while unit is being serviced. Disconnect
switch. Fuses, and code requirements .
Route power wires through opening in unit end panel to connection in unit control box as shown on unit
label diagram and in Fig 6. Unit must be grounded.
Affix crankcase heater warning sticker to unit disconnects switch.
Main Power Supply Wiring
LEGEND
EQUIP GND – Equipment G round
NEC - National Electrical Code
____ Factory Wiring
----- Field Wiring
Fig. 6 ___ Main Power Supply Wiring
8

9
PRE-START-UP
Evacuate and Dehydrate the entire refrigerant system by either of the methods described in Carrier
Standard Service Techniques Manual, Chapter 1.
Leak Test the entire refrigerant system by the pressure method described in Carrier Standard Service
Techniques Manual, Chapter l. Use R-22 at approximately 25 psig (172.4 kPa) backed up with an inert
gas to a total pressure not to exceed 245 psig (1689 kPa).
Turn on Crankcase Heaters for 24 hours before starting the unit to be sure all the refrigerant is
out of the oil. To energize the crankcase heaters, proceed as follows.
1. Set the space thermostat set point above the space temperature so there is no demand for
cooling.
2. Close the field disconnect
3. Turn the fan circuit breaker on. Leave the compressor circuit breakers off. The crankcase
heaters are now energized.
Add Preliminary Charge to the refrigerant system accordingly to Carrier Standard Service Techniques
Manual, Chapter l. By the liquid charging method and charging by weight procedure, charge the units
with approximately the amounts of R-22 refrigerant shown in table l. Physical Data.
Before Starting Unit ensure the following:
1. Compressor oil level must be at least within sight in the compressor sight glass. Add oil if
necessary (see Tables l).
2. Compressor hold down bolts must be snug, but not tight.
Refer to Compressor Mounting section and tag on compressor foot.
3. All internal wiring connections must be tight; all barriers and covers must be in place.
4. Electrical power source must agree with unit nameplate rating .
5. All service valves must be open.
6. Crankcase heater must be firmly locked into the compressor crankcase.
START- UP
To Start Unit – Set thermostat set point
below the space temperature. After starting
unit, there is a delay of at least 3 seconds
before compressor starts.
Oil Charge (see Tables l.) – Allow unit to run
for about 20 minutes. Stop unit and check
compressor oil level at sight glass. Add oil if
necessary to bring oil to the correct level show
in Fig 8. Use only Carrier-approved
compressor oil. Approved oils are:
Witco Chemical Corp ………………Suniso 3GS
Texaco, Inc …………………………..WF32
Petroleum specialties Co ..…………Cryol 150
Fig.7
Do not reuse drained oil or use any oil that has been exposed to atmosphere. Procedures for
adding or removing oil are given in Carrier Standard Service Techniques Manual, Chapter l.,
Refrigerants.
If oil is added, run unit for additional 10 minutes. Stop unit and check oil level. If level is still low , add oil
only after determining that piping system is designed for proper oil return and that the system is not
leaking oil.

10
SERVICE
Capacity Control –A suction pressure-actuated unloader controls 2 cylinders and provides
capacity control. Unloaders are factory set (see Tables l.), but can be field adjusted as described in
the 2 following sections.
Time Guard ll Circuit – Prevents short – cycling by providing a delay of approximately 5 minutes
before restarting compressor after shutdown from safety device action.
On start-up, the Time Guard II time causes a delay of approximately 3 seconds after thermostat
closes.
On compressor shutdown, the time recycles for approximately 5 minutes. During this time, the
compressor cannot restart.
Refer to Fig. 8 and to label diagram on unit.
Fig.8 - Timer Sequence chart
Crankcase Heater – The heater prevents refrigerant migration and compressor oil dilution during
shutdown whenever compressor is not operating. It is wired into the control circuit. and cycles with
the compressor; the heater is off when compressor is running ,and on when compressor is off.
Both compressor service valves must be closed whenever the crankcase heater is for more than 6
hours. The crankcase heater is operable as long as the control circuit is energized.
Outdoor Fans – Each fan is supported by a formed wire mount bolted to the fan deck and covered
with a wire guard. The exposed end of the motor shaft is covered with a rubber boot. In case a fan
motor must be repaired or replaced, be sure the rubber boot is put back on when the fan is
reinstalled and be sure the fan guard is in place before starting the unit. Fan motors have
permanently lubricated bearings.
38AE010
-
015
38AE010
-
015

11
Lubrication
FAN MOTORS have sealed bearings. No provisions are made for lubrication.
COMPRESSOR has its own oil supply. Loss of oil due to a leak in the system should be the only
reason for adding oil after the system has been in operation. See oil Charge section.
Cleaning Coils –The coils can be cleaned
with a vacuum cleaner, washed out with
water, blown out with low-pressure
compressed air, or brushed (do not use
wire brush).Fan motors are drip-proof.
Clean outdoor coil annually or as required
by location outdoor air conditions. Inspect
coil monthly, and clean as required. Fins
are not continuous through coil sections;
dirt and debris may pass through first
section, become trapped between the 2
rows of fins (38AE020) or 3 rows of fins
(38AE010, 015,025-060) and restrict
outdoor airflow. Use a flashlight to
determine if dirt or debris has collected
between coil sections. Clean coil as
follows.
1. Turn off unit power.
2. Remove screws holding rear corner
posts and top cover in place. Pivot to
p
cover up 12 to 18 in.(305 to 457 mm)
and support with a rigid support. See
Fig 9.
3. Remove clips securing tube sheets
together at the return bend end of the
coil. Carefully spread the ends of the
coil rows apart by moving the outer
sections. See Fig 10.
4. Using a water hose, or other suitable
equipment, flush down between the
sections of coil to remove dirt and
debris.
5. Clean the remaining surfaces in the
normal manner.
6. Reposition outer coil sections.
7. Reinstall clips, which secure tube
sheets.
8. Replace to cover and rear corner
posts.
Fig.15—Pivot and Support Top Cover Fig.16—Coil Cleaning (Typical)

12
TROUBLESHOOTING PROBLEM
Problem Solution
COMPRESSOR DOES NOT RUN
Contractor Open
1. Power off.
2. Fuses blown in field power circuit.
3. No control power.
4. Thermostat circuit opens.
5. Time Guard ll device not operating.
6. Compressor circuit breaker tripped.
7. Safety device lock-out circuit
active.
8. Low-pressure switch opens.
9. High-pressure switch open.
10. Compressor over temperature
switch open.
11. Loose electrical connections.
12. Compressor stuck.
Contractor Closed
1. Compressor leads loose.
2. Motor windings open.
3. Single phasing.
COMPRESSOR STOPS ON HIGH-
PRESSURW SWITCH
Outdoor Fan On
1. High-pressure switch faulty.
2. Reversed fan rotation
3. Airflow restricted.
4. Air recalculating.
5. Non condensable in system.
6. Refrigerant overcharge.
7. Line voltage incorrect.
8. Refrigerant system restrictions.
Outdoor Fan Off
1. Fan slips on shaft.
2. Motor not running.
3. Motor bearings stuck.
4. Motor overload open.
5. Motor burned out.
COMPRESSOR CYCLES ON LOW-
PRESSURE SWITCH
Indoor-Air Fan Running
1. Compressor suction service valve
partially closed.
2. Liquid line solenoid valve(s) fails to
open.
3. Filter drier plugged.
4. Expansion valve power head
defective.
5. Low refrigerant charge.
1. Restore power.
2. After finding cause and correcting. Replace with
correct size fuse.
3. Check secondary fuse(s); replace with correct type
and size.
4. Check thermostat setting.
5. Check Time Guard ll devices.
6. Check for excessive compressor current draw.
Reset breaker; replace if defective.
7. Reset lockout circuit at thermostat or circuit
breaker.
8. Check for refrigerant undercharge, obstruction of
indoor airflow, or whether compressor suction
shutoff valve is fully open. Be sure outdoor fans
are operating correctly.
9. Check for refrigerant overcharge, obstruction of
outdoor airflow, air in system. or whether
compressor discharge valve is fully open. Be sure
outdoor fans are operating correctly.
10. Check for open condition. Allow for reset. Replace
if defective.
11. Tighten all connections.
12. See compressor service literature.
1. Check connections
2. See compressor service literature.
3. Check for blown fuse. Check for loose connection
at compressor terminal.
1. Replace switch.
2. Confirm rotation, correct if necessary.
3. Remove obstruction.
4. Clear airflow area.
5. Purge and recharge as required.
6. Purge as required.
7. Consult Power Company.
8. Check or replace filter drier, expansion valve, etc.
Check that compressor discharge service valve is
fully open.
1. Tighten fan hub set screws.
2. Check power and capacitor.
3. Replace bearings.
4. Check overload rating. Check for fan blade
obstruction.
5. Replace motor.
1. Open valve fully.
2. Check liquid line solenoids valve (s) for proper
operation Replace if necessary.
3. Replace filter drier.
4. Replace power head.
5. Add charge. Check low-pressure switch setting.

13
TROUBLESHOOTING (cont.)
Problem Solution
COMPRESSOR CYCLES ON LOW-
PRESSURE SWITCH (cont.)
Airflow Restricted
1. Coil iced up.
2. Coil dirty.
3. Air filters dirty.
4. Dampers closed.
Indoor-Air Fan Stopped
1. Electrical connections loose.
2. Fan relay defective.
3. Motor overload open.
4. Motor defective.
5. Fan belt broken or slipping.
COMPRESSOR RUNNING BUT COOLING
INSUFFICIENT
Suction pressure low
1. Refrigerant charge low.
2. Head pressure low.
3. Air filters dirty.
4. Expansion valve power head
defective.
5. Indoor coil partially iced.
6. Indoor airflow restricted.
Suction Pressure High
1. Unloaders not functioning.
2. Compressor valve defective.
3. Heat load excessive.
UNIT OPERATES TOOLONG OR
CONTINUOUSLY
1. Low refrigerant charge.
2. Control contacts fused.
3. Air in system.
4. Partially plugged expansion valve
or filter drier.
SYSTEM IS NOISY
1. Piping vibration.
2. Compressor noisy.
COMPRESSOR LOSES OIL
1. Leak in system.
2. Crankcase heaters not energized
during shutdown.
3. Improper interconnecting piping
design.
FROSTED SUCTION LINE
Expansion valve admitting excess refrigerant.
HOT LIQUID LINE
1. Shortage of refrigerant due to leak.
2. Expansion valve opens too wide.
FROSTED LIQUID LINE
1. Restricted filter drier.
2. Liquid line solenoid valve partially
closed.
COMPRESSOR WILL NOT UNLOAD
1. Defective unloader.
2. Defective capacity control solenoid
valve (if used).
3. Miswired capacity control liquid line
solenoid(if used).
4. Weak,broken ,or wrong valve body
spring.
COMPERSSOR WILL NOT LOAD
1. Miswired capacity control liquid line
solenoid (if used).
2. Defective capacity control solenoid
valve (if used).
3. Plugged strainer (high side).
4. Stuck or damaged unloader piston
or piston ring (s)
1. Check refrigerant charge.
2. Clean coil fins.
3. Clean or replace filters.
4. Check damper operation and position.
1. Tighten all connections.
2. Replace relay.
3. Power supply.
4. Replace motor.
5. Replace or tighten belt.
1. Add refrigerant.
2. Check refrigerant charge and check or replace
filters.
3. Clean or replace filters.
4. Replace power head.
5. Check low-pressure setting.
6. Remove obstruction.
1. Check unloader adjustments and Check unloader
setting.
2. See compressor service literature.
3. Check for open doors or windows in vicinity of fan
coil.
1. Add refrigerant.
2. Replace control.
3. Purge and evacuate system.
4. Clean or replace.
1. Support piping as required.
2. Check valve plates for valve noise. Replace
compressor if bearings are worn.
1. Repair leak.
2. Check wiring and relays. Check heater and replace
if defective.
3. Check piping for oil return. Replace if necessary
Adjust expansion valve
1. Repair leak and recharge.
2. Adjust expansion valve.
1. Remove restriction or replace.
2. Replace valve.
1. Replace unloader.
2. Replace valve.
3. Rewire correctly.
4. Replace spring.
1. Rewire correctly.
2. Replace valve.
3. Clean or replace strainer.
4. Clean or replace the necessary parts.

14
38AE020 / 38AF020
Wiring Diagram

15
Wiring Diagram
38AE025, 030, 040 / 38AF025, 030, 040

16
Wiring Diagram
38AE050, 060 / 38AF050,060

17
Control Module (CM) Operation
When voltage is applied the power LED (DSI) will continuously flash 1/4 second off. The module starts a 3-minute
compressor delay timer. This delay can be bypassed by pressing the override switch for at least 1/2 second. The
Status LED (DS3) must be flashing or the override switch will not function.
On a call for cooling, the control module checks for 24vac to be present at T1 for a period of 7 seconds. It also
checks that the 3-minute compressor delay has clasped or overridden and also checks the state of the HPS/COTP. If
on alarms are detected nor delays are active the module will energize the compressor contactor relay. A timer is
started to provide minimum 3½ minute compressor run period.
During compressor operation the module continuously checks the HPS/COTP state ( Status LED ( DS3)and K1 LED
(DS4) are ”NO” steady). If the circuit poens (24 vac not present at T7) the module will immediately shut down the
compressor and display the alarm Alarm LED (DS2) “ON” steady ). Power must be cycled to restore normal control
operation.
The OPS state is ignored during the first 60 seconds of operation .After this time if the OPS is open (24 vac not
present at T9) the compressor will be shut down. Alarm LED (DS2) displays the state of the OPS. A double blink (2-
1/4 ) second blinks, I second 0ff) indicates the OPS is open . If the OPS opens during operation and remains open for
longer that 60 seconds the module will lockout unit operation and display the alarm. Power must be cycled to restore
normal control operation.
The LPS is monitored during a call for cooling . The LPS is ignored during the first 2 ½ minutes of operation . The
Alarm LED (DS2) displays the state of the LPS. A single blink (1/4 second on, 1 second off) indicates that the LPS is
open. If the LPS remains open after 2 ½ minutes or opens later during the call for cooling (24 vac not present at
T11) the module shuts down the compressor. The 3-minute compressor delay is started and the cycle repeats. If the
call for cooling remains and this LPS cycle is repeated 3 times the module will lock out and display the alarm. Power
must be cycled to restore normal control operation.
When the call for cooling is satisfied and the compressor has run for at least 3 ½ minutes the module shuts off the
compressor. The CM stats the 3-minute compressor delay timer.

18
TART-UP CHECKLIST
A. Preliminary Information
Outdoor: model no._______________________ Serial no.___________
Indoor: air handler manufacturer____________________________
Model no._____________________________ Serial no.__________
Additional accessories_________________________________________
B. Pre-Start-Up
Outdoor Unit
Is there any shipping damage? ____________ (y/n)_________________
If so, where: ______________________________________________________
Will this damage prevent unit start-up? (y/n)________________
Check power suppy. Does it agree with unit? (y/n)_____________
Has the ground wire been connected? (y/n)______________
Has the circuit protectionbeen sized and installed properly? (y/n)_______
Are the power wires to the unit sized and installed properly? (y/n)______
Have compressor holddown bolts been loosened (snubber washers are snug,but not tight)? (y/n)___
Controls
Are thermostat and indoor fan control wiring
Connections made and checked? (y/n)________________
Are all wiring terminals (including main power supply ) tight? (y/n) ___________________
Has crankcase heater been energized for 24 hours? (y/n) _____
Piping
Are loquid line solenoid valves located at the evaporator coils as required? (y/n) _______________
Have leak checks been made at compressor, condenser, evaporator(s), Txvs (thermostatic expansion
valves), solenoid valves, filter driers, and fusible plugs with a leak detector ? (y/n) ___________________
Locate, repair, and report any leaks.___________________________
Have all compressor service valves been fully opened (backseated)? (y/n) ___________________
Have liquid line service valves been opened? (y/n) ____________
Is the oil level in each compressor crankcase visible in the compressor sight glasses? (y/n) ____________
Check Voltage Imbalance
Line-to-line volts: ab____v ac____v bc_____v
(ab+ac+bc)/3 = average voltage = _____v
Maximum deviation from average voltage=_______v
Voltage imbalance=100 x (max deviation)/(average voltage)=________%
If over 2% voltage imbalance,do not attempt to start system !
Call local Power Company for assistance.
C. Start-Up
Check evaporator fan speed and record.___________
Check condenser fan speed and record.___________
After at least 10 minutes running time ,record the following measurements:
Oil pressure _______________________
Suction pressure _____________________
Suction line temp __________________________-
Discharge pressure ________________________
Entering condenser air temp _____________________
Leaving condenser air temp _______________________
evap entering-air db (dry bulb) temp __________________
evap entering air wb (wet bulb) temp ___________________
evap leaving air db temp ______________________
evap leaving air wb temp _______________________
Compressor amps (L1/L2/L3) __________/______________/____________
Check the compressor oil level sight glasses; are the sight glasses showing oil level in view? (y/n)____________
Notes:
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_______________________________
14-15th Fl’, 1858/63-74 Bangna-Trad Road Km. 4.5, Bangna Bnagkok 10260 Thailand Tel. [phone] Fax: [phone]
38AE_AF_ENG/10/2015
%I1#AQ"%%&>%>!/> -J3&>%>I!&>%>/DI#*;K#/¡J+ø¡