Carrier 50FC 08-16 Series Installation and user guide

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53500301-01 Printed in U.S.A. Form 50FC-8-16-01SM Pg 1 11-23 Replaces: NEW
Service and Maintenance Instructions
CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 2
UNIT ARRANGEMENT AND ACCESS . . . . . . . . . . . . 2
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . 3
Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
SUPPLY FAN (BLOWER) SECTION . . . . . . . . . . . . . . 4
Supply Fan (Direct-Drive) . . . . . . . . . . . . . . . . . . . . . . 4
Staged Air Volume . . . . . . . . . . . . . . . . . . . . . . . . . . 13
COOLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Condenser Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Condenser Coil Maintenance and Cleaning 
Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . 13
Evaporator Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Evaporator Coil Metering Devices . . . . . . . . . . . . . . 15
THERMOSTATIC EXPANSION VALVE (TXV) . . . . . 15
TXV Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Replacing TXV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Refrigerant System Pressure Access Ports . . . . . . 15
PURON (R-410A) REFRIGERANT . . . . . . . . . . . . . . . 16
Refrigerant Charge . . . . . . . . . . . . . . . . . . . . . . . . . . 16
COMPRESSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Replacing Compressor . . . . . . . . . . . . . . . . . . . . . . . 22
Compressor Rotation . . . . . . . . . . . . . . . . . . . . . . . . 22
Filter Drier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Condenser-Fan Adjustment . . . . . . . . . . . . . . . . . . . 22
Troubleshooting Cooling System . . . . . . . . . . . . . . 23
CONVENIENCE OUTLETS . . . . . . . . . . . . . . . . . . . . 24
Convenience Outlets . . . . . . . . . . . . . . . . . . . . . . . . 24
Installing Weatherproof Cover . . . . . . . . . . . . . . . . . 24
Non-Powered Type . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Unit-Powered Type . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Duty Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Fuse on Powered Type . . . . . . . . . . . . . . . . . . . . . . . 25
ELECTRIC HEATERS . . . . . . . . . . . . . . . . . . . . . . . . 25
Completing Heater Installation . . . . . . . . . . . . . . . . 26
SMOKE DETECTORS . . . . . . . . . . . . . . . . . . . . . . . . 27
System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Smoke Detector Sensor . . . . . . . . . . . . . . . . . . . . . . 27
Smoke Detector Locations . . . . . . . . . . . . . . . . . . . . 27
Completing Installation of Return Air 
Smoke Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
FIOP Smoke Detector Wiring and Response . . . . . 30
SENSOR AND CONTROLLER TESTS . . . . . . . . . . .31
Sensor Alarm Test . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Controller Alarm Test . . . . . . . . . . . . . . . . . . . . . . . .31
Dirty Controller Test . . . . . . . . . . . . . . . . . . . . . . . . .31
Dirty Sensor Test . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Changing the Dirt Sensor Test . . . . . . . . . . . . . . . . .31
Remote Station Test . . . . . . . . . . . . . . . . . . . . . . . . .32
SD-TRK4 Remote Alarm Test Procedure . . . . . . . .32
Remote Test/Reset Station Dirty Sensor Test . . . .32
Dirty Sensor Test Using an SD-TRK4 . . . . . . . . . . .32
Detector Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
PROTECTIVE DEVICES . . . . . . . . . . . . . . . . . . . . . . .33
Compressor Protection . . . . . . . . . . . . . . . . . . . . . . .33
Relief Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Control Circuit, 24-V . . . . . . . . . . . . . . . . . . . . . . . . .34
SYSTEMVU CONTROL SYSTEM . . . . . . . . . . . . . . . .35
SystemVu Interface . . . . . . . . . . . . . . . . . . . . . . . . . .35
Additional SystemVu Installation and
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . .35
ECONOMIZER SYSTEMS . . . . . . . . . . . . . . . . . . . . .36
EconoMi$er2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
EconoMi$er IV (Field-Installed Accessory) . . . . . . .37
Economi$er X (Factory Option) . . . . . . . . . . . . . . . .46
PRE-START-UP/START-UP . . . . . . . . . . . . . . . . . . . .57
START-UP, GENERAL . . . . . . . . . . . . . . . . . . . . . . . .58
Unit Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
Additional Installation/Inspection . . . . . . . . . . . . . .58
Return-Air Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
Outdoor-Air Inlet Screens . . . . . . . . . . . . . . . . . . . . .58
Compressor Mounting . . . . . . . . . . . . . . . . . . . . . . .58
Internal Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
Refrigerant Service Ports . . . . . . . . . . . . . . . . . . . . .58
Compressor Rotation . . . . . . . . . . . . . . . . . . . . . . . .58
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
Ventilation (Continuous Fan) . . . . . . . . . . . . . . . . . .59
FASTENER TORQUE VALUES . . . . . . . . . . . . . . . . .59
START-UP, SYSTEMVU CONTROLS . . . . . . . . . . . .59
APPENDIX A — MODEL NUMBER 
NOMENCLATURE . . . . . . . . . . . . . . . . . . . . . . . . . .60
APPENDIX B — PHYSICAL DATA . . . . . . . . . . . . . . .61
APPENDIX C — FAN PERFORMANCE . . . . . . . . . . .64
APPENDIX D — WIRING DIAGRAMS . . . . . . . . . . . .85
APPENDIX E — LOW AMBIENT CONTROL SENSOR
LOCATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . .CL-1
50FC**08-16
Single Package Rooftop Electric Cooling Unit
with Puron®(R-410A) Refrigerant
7.5 to 15.0 Nominal Tons

2
SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment can be
hazardous due to system pressure and electrical components. Only
trained and qualified service personnel should install, repair, or
service air-conditioning equipment. Untrained personnel can per-
form the basic maintenance functions of replacing filters. Trained
service personnel should perform all other operations.
When working on air-conditioning equipment, observe precau-
tions 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
unbrazing operations. Have fire extinguishers available for all
brazing operations.
Follow all safety codes. Wear safety glasses and work gloves. Use
quenching cloth for brazing operations. Have fire extinguisher
available. Read these instructions thoroughly and follow all warn-
ings or cautions 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 aware of the potential for physical injury hazards.
Understand the signal words DANGER, WARNING, and CAU-
TION. These words are used with the safety ALERT symbol.
DANGER indicates a hazardous situation which, if not avoided,
will result in death or severe personal injury. WARNING indi-
cates a hazardous situation which, if not avoided, could result in
death or personal injury. CAUTION indicates a hazardous situa-
tion which, if not avoided, could result in minor to moderate injury
or product and property damage. IMPORTANT is used to address
practices not related to physical injury. NOTE is used to highlight
suggestions which will result in enhanced installation, reliability,
or operation.
UNIT ARRANGEMENT AND ACCESS
General
Figures 1-4 show general unit arrangement and access
locations.
Fig. 1 — Typical Access Panel Locations
(size 8-14 units)
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injury or
death.
Before performing service or maintenance operations on unit,
LOCKOUT/TAGOUT the main power switch to unit.
Electrical shock and rotating equipment could cause severe
injury.
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injury or
death.
Units with convenience outlet circuits can use multiple
disconnects. Check convenience outlet for power status before
opening unit for service. Locate the disconnect switch and lock
it in the open position it. LOCKOUT/TAGOUT this switch to
notify others.
WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury,
death and/or equipment damage.
Puron (R-410A) refrigerant systems operate at higher
pressures than standard R-22 systems. Do not use R-22 service
equipment or components on Puron refrigerant equipment.
WARNING
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in death, serious
personal injury and/or property damage.
Never use air or gases containing oxygen for leak testing or for
operating refrigerant compressors. Pressurized mixtures of air
or gases containing oxygen can lead to an explosion.
WARNING
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in death, serious
personal injury and/or property damage.
Never use non-certified refrigerants in this product. Non-
certified refrigerants could contain contaminates that could
lead to unsafe operating conditions. Use ONLY refrigerants
that conform to AHRI Standard 700.
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in reduced unit
performance or unit shutdown.
High velocity water from a pressure washer, garden hose, or
compressed air should never be used to clean a coil. The force
of the water or air jet will bend the fin edges and increase
airside pressure drop.
IMPORTANT: Lockout/Tag-out is a term used when
electrical power switches are physically locked preventing
power to the unit. A placard is placed on the power switch
alerting service personnel that the power is disconnected.
Filter Access Panel
Indoor Coil Access Panel

3
Fig. 2 — Typical Access Panel Locations
(size 16 units)
Fig. 3 — Blower Access Panel Location
(size 8-14 units)
Fig. 4 — Blower Access Panel Location
(size 16 units)
Routine Maintenance
These items should be part of a routine maintenance program, to
be checked every month or two, until a specific schedule for each
can be identified for this installation:
QUARTERLY INSPECTION 
(AND 30 DAYS AFTER INITIAL START)
• Return air filter replacement
• Outdoor hood inlet filters cleaned
• Condenser coil cleanliness checked
• Condensate drain checked
SEASONAL MAINTENANCE
These items should be checked at the beginning of each season (or
more often if local conditions and usage patterns dictate):
Air Conditioning
• Ensure outdoor fan motor mounting bolts are tight
• Ensure compressor mounting bolts are tight
• Inspect outdoor fan blade positioning
• Ensure control box is clean
• Check control box wiring condition
• Ensure wire terminals are tight
• Check refrigerant charge level
• Ensure indoor coils are clean
• Check supply blower motor amperage
Electric Heating
• Inspect power wire connections
• Ensure fuses are operational
• Ensure manual reset limit switch is closed
Economizer or Outside Air Damper
• Check inlet filters condition
• Check damper travel (economizer)
• Check gear and dampers for debris and dirt
Air Filters and Screens
Each unit is equipped with return air filters. If the unit has an econ-
omizer, it will also have an outside air screen. If a manual outside
air damper is added, an inlet air screen will also be present.
Each of these filters and screens will need to be periodically
replaced or cleaned.
Filters
RETURN AIR FILTERS
Return air filters are disposable fiberglass media type. Access
to the filters is through the small lift-out panel located on the
rear side of the unit, above the evaporator/return air access
panel. (See Fig. 5.)
Filter Access Panel
Indoor Coil Access Panel
Control Box
Access Panel
Indoor
Access
Panel
Flue
Hood
Control Box
Access Panel
Blower
Access Panels
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this CAUTION can result in premature wear
and damage to equipment.
DO NOT OPERATE THE UNIT WITHOUT THE RETURN
AIR FILTERS IN PLACE.
Dirt and debris can collect on heat exchangers and coils
possibly resulting in a small fire. Dirt buildup on components
can cause excessive current used resulting in motor failure.

4
To remove the filters:
1. Grasp the bottom flange of the upper panel.
2. Lift up and swing the bottom out until the panel disen-
gages and pulls out.
3. Reach inside and extract the filters from the filter rack.
4. Replace these filters as required with similar replacement
filters of same size.
To re-install the access panel:
1. Slide the top of the panel up under the unit top panel.
2. Slide the bottom into the side channels.
3. Push the bottom flange down until it contacts the top of
the lower panel (or economizer top).
OUTSIDE AIR HOOD
Outside air hood inlet screens are permanent aluminum-mesh
type filters. Check these for cleanliness. Remove the screens
when cleaning is required. Clean by washing with hot low-pres-
sure water and soft detergent and replace all screens before re-
starting the unit. Observe the flow direction arrows on the side of
each filter frame.
ECONOMIZER INLET AIR SCREEN
This air screen is retained by filter clips under the top edge of the
hood. (See Fig. 5.)
Fig. 5 — Filter Installation
To remove the filter, open the filter clips. Re-install the filter by
placing the frame in its track, then closing the filter clips.
MANUAL OUTSIDE AIR HOOD SCREEN
This inlet screen is secured by a retainer angle across the top edge
of the hood. (See Fig. 6.)
Fig. 6 — Screens Installed on Outdoor-Air Hood
To remove the screen, loosen the screws in the top retainer and slip
the retainer up until the filter can be removed. Re-install by plac-
ing the frame in its track, rotating the retainer back down, and
tightening all screws.
SUPPLY FAN (BLOWER) SECTION
Supply Fan (Direct-Drive)
All FC units have the EcoBlue™ direct drive vane axial fan sys-
tem. The fan is driven by an ECM motor with speed that is user
set through the Unit Control Board (UCB). Speeds are fully con-
figurable from 40% to 100% of motor’s maximum speed.
See Fig. 7 and 8.
Fig. 7 — Direct-Drive Supply Fan Assembly
17-1/4"
Divider
Barometric
Relief
Cleanable
Aluminum
Filter Filter
Hood
Filter
Clip
Outside
Air
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury or
death.
Before performing service or maintenance operations on unit,
LOCKOUT/TAG-OUT the main power switch to unit.
Electrical shock and rotating equipment could cause severe
injury.
Screws
Motor
Plug
Fan
Motor
ECM Motor

5
Fig. 8 — ECM Motor Plug Connectors
EVALUATING MOTOR SPEED
The direct drive ECM blower motor uses a constant speed design.
Motor speed is controlled by a 0-10 vdc signal, where 10 vdc is
equal to motor’s maximum rpm.
SELECTING FAN SPEED
All units come factory set for 7.8 vdc or approximately 78% of the
motor’s maximum speed. Fan speed should be set per job specifi-
cation cfm (cubic feet per minute) and ESP (external static pres-
sure) required and per fan speed set up label included on the unit’s
high voltage cover. In some cases, the Fan Speed Set Up label may
already include the field setting if unit was previously installed.
Check the box on the lower half of the label to see if the field volt-
age setting was filled in and if so, set fan speed to that voltage.
Otherwise see detailed instructions below.
NOTE: Fan Speed Setup is for full load airflow. If the unit has
multiple stages of cooling, low cool and ventilation may operate at
lower fan rpms. This offset is factory set and controlled by the
UCB. If fan speed verification is being done with a strobe, fan
speed should be verified in all unit operation modes.
Units with Electro-mechanical controls
The Fan Speed set up controls are located on the lower section of
the Unit Control Board (UCB). See Fig. 9 for location.
1. Check the job specifications for the cfm (cubic feet per
minute) and ESP (external static pressure) required.
2. Using the chart on the Fan Speed Set Up labels (see Fig. 10),
calculate the vdc from the cfm and ESP for the base unit.
3. If installing any accessories listed at the bottom of the Set Up
Label, add accessory vdc to base unit vdc in upper portion of
label. For electric heaters use only one adder. (ex. 2 stage
heater uses only 2 stage adder, not 1 stage plus 2 stage).
NOTE: The Fan Speed Set Up labels are located on the High
Voltage cover in the Control Box.
4. Connect a multimeter to the vdc terminals on the UCB.
5. Set the Range Switch to either A, B, or C per the Switch
Range table.
6. Using a straight blade screwdriver turn the vdc control dial
to fine tune the vdc reading.
7. Record the reading in the Field Setting field.
NOTE: For units equipped with the Humidi-MiZer option, when
replacing the UCB cut JMP 1,2 and 3 in the REHEAT/HP section
of the replacement UCB.
Fig. 9 — UCB Fan Speed Controls
123
456
789
10 11 12
CTL Signal CommonSerial (R/T)
Safety Relay
Power L1
Power L2
Power L3
10 vdc Source
0-10 vdc signal
Earth Ground
Safety Relay
PWM signal
WHITE
BLACK
YELLOW
BLUE
YEL/GRN
RED
GRAY
RED
PINK
ORANGE
VIOLET
Fan Speed Set Up Controls

6
NOTE: Values in the Field Accessories section are VDC adders.
Fig. 10 — Example of Fan Speed Set Up Labels for Electro-Mechanical Controls
Factory Setting:
9.0 VDC
Field Setting:
V
Switch Range:
A
B
C
B
AC
Field Accessories:
ESP in. wg
V DC Calculator
CFM
0.2
5.4
5.8
6.1
6.5
6.8
7.2
7.6
7.9
8.3
1500
1625
1750
1875
2000
2125
2250
2375
2500
0.1
0.4
6.2
6.5
6.8
7.1
7.4
7.7
8.0
8.4
8.7
0.1
0.6
6.9
7.1
7.4
7.7
7.9
8.2
8.5
8.8
0.1
0.8
7.5
7.7
8.0
8.2
8.5
8.7
9.0
0.1
1.0
8.1
8.3
8.5
8.7
9.0
0.1
1.2
8.6
8.8
9.0
9.2
0.1
1.4
9.1
9.3
9.5
0.1
1.6 1.8 2.0
9.6
0.1Economizer
1 Stage E Heat
2 Stage E Heat
UNIT MODEL NUMBER
4.1 - 7.5
6.9 - 8.7
7.7 - 10.0
0.2
0.3
0.2
0.3
0.2
0.3
0.2
0.3
0.2
0.3
0.2
0.3
0.2
0.3
0.2
0.3
9.8
9.9
9.7
9.99.5
9.7
10.0
9.2
9.5
9.8
9.3
9.69.2
Record field setting here
*
* Overlap in A, B, C switch range
designed for maximum field
adjustment potential. For example
7.2 can be set at either A or B.

7
Units with SystemVu™ controls
On units equipped with the factory-installed SystemVu con-
troller the Fan Speed settings are accessed through the
SystemVu interface.
1. Check the job specifications for the cfm (cubic feet per
minute) and ESP (external static pressure) required.
2. Using the chart on the Fan Speed Set Up labels (see Fig. 11),
calculate the rpm from the cfm and ESP for the base unit.
3. If installing any accessories listed at the bottom of the Set
Up Label, add accessory rpm to base unit rpm in upper
portion of label. For electric heaters use only one adder.
(ex. 2 stage heater uses only 2 stage adder, not 1 stage plus
2 stage)
NOTE: The Fan Speed Set Up labels are located on the High
Voltage cover in the Control Box.
4. Press any key on the SystemVu interface to activate the
display backlight and then press the MENU key.
5. Using the UP and DOWN arrow keys highlight SET-
TINGS and then press ENTER.
6. Use the DOWN arrow key highlight the UNIT CONFIG-
URATIONS menu then press ENTER.
7. Highlight UNIT CONFIGURATIONS then press ENTER.
8. Highlight INDOOR FAN and then press ENTER.
9. Refer to the job specifications to set the following, deter-
mining the values per the rpm Calculator label (see
Fig. 11). Use the UP and DOWN arrow keys and the
BACK key to set the values. Press ENTER after setting
each value to continue to the next selection.
• IDF VENT SPD
• IDF HEAT SPD
•IDFLOWCOOLSPD
• IDF HIGH SPD
• IDF FREE COOL SPD
For further details see the FC/GC Series Single Package Rooftop
Units with SystemVu Controller Controls, Start-up, Operation and
Troubleshooting manual.
NOTE: Values in the Field Accessories section are VDC adders.
Fig. 11 — Example of Fan Speed Set Up Labels for SystemVu™ Controls
A
Field Accessories:
2500
Economizer
ESP in. wg
RPM Calculator
CFM
0.2
1301
1381
1463
1548
1633
1720
1808
1897
1987
1500
1625
1750
1875
2000
2125
2250
2375
66
80
107
0.4
1477
1544
1615
1688
1764
1842
1921
2003
2068
66
0.6
1639
1699
1763
1828
1897
1967
2040
2115
2191
0.8
1788
1843
1902
1962
2025
2090
2157
2227
2298
66
1.0
1925
1976
2031
2087
2146
2208
2271
2336
66
1.2
2054
2101
2152
2206
2262
2320
2380
66
1.4
2174
2220
2268
2318
2372
66
1.6 1.8 2.0
2289
2332
2378
66 66
80 80 80 80 80 80 80
107 107 107 107 107 107 107
1 Stage E Heat
2 Stage E Heat
UNIT MODEL NUMBER

8
TROUBLESHOOTING THE ECM MOTOR
EcoBlue™ motors are designed with several built-in protections
included in the motor software. If the motor detects a fault it will
safely shut down. See Table 5, “Supply Fan Motor Logic and
Safety Relays” on page 34 for a complete list.
Troubleshooting the motor requires a voltmeter.
1. Disconnect main power to the unit.
2. Disconnect motor plug in supply section of the unit.
3. Restore main unit power.
4. Check for proper line voltage at motor power leads Black
(PL1-1), Yellow (PL1-2), and Blue (PL1-3). Blue is only
present on 3-phase motors. See the following table.
5. Disconnect main power.
6. Reconnect motor plug in supply section of unit.
7. Restore main power.
8. Check for proper motor control voltage signal of 9.7 vdc
to 10.3 vdc at IFM-1 and IFM-3 on Unit Control Board
(UCB). See Fig. 12.
9. Using a jumper wire from unit control terminals R to G,
engage motor operation.
10. Verify control signal from user speed selection switch by
placing voltmeter taps in provided terminals marked vdc.
Signal should be between 3.8 vdc and 10.3 vdc.
11. If the motor does not start and run, remove the fan assem-
bly and replace the motor with one having the same part
number. Do not substitute with an alternate design motor
as the voltage/speed programming will not be the same as
that on an original factory motor.
Fig. 12 — Supply Fan Control Wiring Diagram
50FC UNIT
VOLTAGE MOTOR VOLTAGE MIN-MAX VOLTS
208/230 230 187-253
460 460 360-506
575 575 517-633

9
Removing the Motor and Fan Assembly
NOTE: Due to press fit design of composite Rotor on Motor, it is
highly recommended that any time a motor is replaced the fan
rotor is replaced as well. The rest of the assembly may be reused.
See Fig. 13.
1. Unplug motor harness from control box harness and cut
wire tie at the fan deck.
2. Unplug connectors from stator temperature limit switch.
3. Remove eight screws at front of stator on fan deck.
4. Slide fan assembly forward a couple of inches to clear rear
brackets and lift assembly out.
Fig. 13 — Fan Assembly Removal
2
3
4
1

10
Disassembling Standard/Medium Motor and Fan Assembly
See Fig. 14.
NOTE: Refer to “Model Number Nomenclature” on page 60,
position 10 for specific unit requirements.
1. Remove 4 screws from U-clips in fan casing.
2. Remove casing from assembly.
3. Remove 3 screws connecting rotor to motor flange.
4. Remove rotor from motor.
5. Remove 4 screws connecting motor to stator.
6. Remove stator from motor.
7. If required, remove fan limit switch from stator.
Fig. 14 — Disassembling Standard or Medium Static
Motor and Fan Assembly
Disassembling High Static Motor and Fan Assembly
See Fig. 15.
NOTE: Refer to “Model Number Nomenclature” on page 60,
position 10 for specific unit requirements.
1. Remove 4 screws from U-clips in fan casing.
2. Remove casing from assembly.
3. Remove 3 screws connecting rotor to motor flange.
4. Remove rotor from motor.
5. Remove 6 screws connecting motor to stator.
6. Remove motor from stator.
7. If required, remove fan limit switch from stator.
Fig. 15 — Disassembling High Static Motor and Fan
Assembly

11
Reassembly of Standard/Medium Motor and Fan Assembly
See Fig. 16.
NOTE: Refer to “Model Number Nomenclature” on page 60,
position 10 for specific unit requirements.
1. Place motor on flat surface.
2. If required, reinstall limit switch on stator with two plastic
fastener plugs (P/N: 48TM005675).
3. Line up keying features on stator and motor and set stator
onto motor. Install four 1/4-20 x 1-in. screws
(P/N: AC67AP170) to attach stator to motor. Tighten to
50 in.-lb (5.65 Nm).
4. Set rotor onto motor flange. Install three 1/4-20 x 1-in.
screws (P/N: AC67AP170) to attach rotor to motor.
Tighten to 50 in.-lb (5.65 Nm).
5. Set casing onto stator. Install four #10-16 x 3/4-in. screws
(P/N: AP13AD128) through U-Clips in casing. Tighten to
14 in.-lb (1.58 Nm).
6. Pull motor harness out through guide feature in stator if
not already completed.
Fig. 16 — Standard/Medium Fan System Re-
Assembly
Reassembly of High Static Motor and Fan Assembly
See Fig. 17.
NOTE: Refer to “Model Number Nomenclature” on page 60,
position 10 for specific unit requirements.
1. Place stator on flat surface.
2. If required, reinstall limit switch on stator with two plastic
fastener plugs (P/N: 48TM005675).
3. Line up keying features on stator and motor and set motor
onto stator. Motor wire Harness should align with guide
feature in stator. Install six 1/4-20 x 1-in. screws
(P/N: AC67AP170) to attach stator to motor. Tighten to
30 in.-lb (3.39 Nm).
4. Set rotor onto motor flange. Install three 1/4-20 x 1-in.
screws (P/N: AC67AP170) to attach rotor to motor.
Tighten to 50 in.-lb (5.65 Nm).
5. Set casing onto stator. Install four #10-16 x 3/4-in. screws
(P/N: AP13AD128) through U-Clips in casing. Tighten to
14 in.-lb (1.58 Nm).
6. Pull motor harness out through guide feature in stator if
not already completed.
Fig. 17 — High Static Fan System Re-Assembly

12
Reinstalling Motor and Fan Assembly
See Fig. 18.
1. Align motor harness/grommet at ~7 o’clock (facing
installer) and align the bottom flats on right and left sides
of fan stator with fan deck ribs. Drop fan assembly down
into fan deck opening and slide back until aluminum stator
is under the rear fan deck brackets.
2. Align (if necessary) two front holes and fasten stator
to fan deck with 8 #10 x 5/8-in. hex head screws
(P/N: AL48AM217). Tighten to 50 in.-lb (5.65 Nm).
3. Reconnect wires for stator temperature limit switch.
4. Pull motor harness tight through grommet and plug it in to
the control box harness and secure in the corner with snap-
in wire tie.
Fig. 18 — Fan Assembly Installation
3
2
4
1

13
Staged Air Volume
All 50FC units with EcoBlue™ technology come factory set to
automatically adjust the indoor fan motor speed in sequence with
the unit’s ventilation, cooling, and heating operation. See Table 1
for fan operation for various modes.
COOLING
Condenser Coil
The condenser coil is fabricated with round tube copper hairpins
and plate fins of various materials and/or coatings (see Model
Number Nomenclature in Appendix A to identify the materials
provided in this unit). The coil may be one-row or composite-type
two-row. Composite two-row coils are two single-row coils fabri-
cated with a single return bend end tubesheet.
Condenser Coil Maintenance and Cleaning 
Recommendation
Routine cleaning of coil surfaces is essential to maintain proper
operation of the unit. Elimination of contamination and removal of
harmful residues will greatly increase the life of the coil and ex-
tend the life of the unit. The following maintenance and cleaning
procedures are recommended as part of the routine maintenance
activities to extend the life of the coil.
REMOVE SURFACE LOADED FIBERS
Surface loaded fibers or dirt should be removed with a vacuum
cleaner. If a vacuum cleaner is not available, a soft non-metallic
bristle brush may be used. In either case, the tool should be ap-
plied in the direction of the fins. Coil surfaces can be easily dam-
aged (fin edges can be easily bent over and damage to the coating
of a protected coil) if the tool is applied across the fins.
NOTE: Use of a water stream, such as a garden hose, against a
surface loaded coil will drive the fibers and dirt into the coil. This
will make cleaning efforts more difficult. Surface loaded fibers
must be completely removed prior to using low velocity clean wa-
ter rinse.
PERIODIC CLEAN WATER RINSE
A periodic clean water rinse is very beneficial for coils that are ap-
plied in coastal or industrial environments. However, it is very im-
portant that the water rinse is made with a very low velocity water
stream to avoid damaging the fin edges. Monthly cleaning as de-
scribed below is recommended. Rinsing coils in the opposite di-
rection of airflow is recommended.
ROUTINE CLEANING OF COIL SURFACES
Periodic cleaning with Totaline®environmentally balanced coil
cleaner is essential to extend the life of coils. This cleaner is avail-
able from Replacement Components Division as part number
P902-0301 for a one gallon container, and part number P902-0305
for a 5 gallon container. It is recommended that all coils, including
standard aluminum, pre-coated, copper/copper or e-coated coils
be cleaned with the Totaline environmentally balanced coil clean-
er as described below. Coil cleaning should be part of the unit’s
regularly scheduled maintenance procedures to ensure long life of
the coil. Failure to clean the coils may result in reduced durability
in the environment.
Avoid use of:
• coil brighteners
• acid cleaning prior to painting
• high pressure washers
• poor quality water for cleaning
Totaline environmentally balanced coil cleaner is nonflammable,
hypo-allergenic, non-bacterial, and a USDA accepted biodegrad-
able agent that will not harm the coil or surrounding components
such as electrical wiring, painted metal surfaces, or insulation. Use
of non-recommended coil cleaners is strongly discouraged since
coil and unit durability could be affected.
Clean coil as follows:
1. Turn off unit power, tag disconnect.
2. Remove all screws from the top panel except the screws
securing the condenser fan to the top panel. See Fig. 19.
Fig. 19 — Location of Screws and Coil Corner Post
3. Remove condenser coil corner post. See Fig. 19. To hold top
panel open, place coil corner post between top panel and cen-
ter post. See Fig. 20.
Table 1 — Percentage of Vdc Setting
UNIT HIGH COOL HEAT LOW COOL VENT
FC08 100% 100% 60% 60%
FC09 100% 100% 50% 50%
FC12 100% 100% 60% 60%
FC14 100% 100% 60% 60%
FC16 100% 100% 66% 66%
WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury,
death and/or equipment damage.
This system uses Puron®refrigerant which has higher
pressures than R-22 and other refrigerants. No other refrigerant
may be used in this system. Gauge set, hoses, and recovery
system must be designed to handle Puron refrigerant. If unsure
about equipment, consult the equipment manufacturer.
Top Panel
Remove screws
from all sides
of top panel
Remove
Screws
Condenser
Fan
Condenser
Coil
Condenser Coil
Corner Post
Center
Post
Compressor
Access Panel

14
Fig. 20 — Propping Up Top Panel
4. Remove the compressor access panel to access the lower coil
clip. The condenser coil corner post may also be removed.
5. Remove the screws from both sides of the 4 coil retaining
clips on the hairpin end of the coil tube sheets. See Fig. 21.
6. Remove the 4 retaining clips.
Fig. 21 — Condenser Coil Clips
7. Draw the inner coil inward to separate the coils for cleaning.
8. Insert a spacer (field-supplied) between the tube sheets to
hold the coils apart. See Fig. 22.
9. Clean the outer coil surface to remove surface loaded
fibers or dirt. See “Remove Surface Loaded Fibers” on
page 13 for details.
10. Use a water hose or other suitable equipment to flush down
between the 2 coil sections to remove dirt and debris. If a
coil cleaner is used be sure to rinse the coils completely
before reassembly.
11. Move the inner coil back into position. Reinstall the 4 coil
clips. Reinstall the top panel and replace all screws.
Fig. 22 — Separating Coil Sections
(Top View)
Totaline Environmentally Balanced Coil Cleaner Application
Equipment
• 2-1/2 gallon garden sprayer
• Water rinse with low velocity spray nozzle
Totaline Environmentally Balanced Coil Cleaner Application
Instructions
1. Proper eye protection such as safety glasses is recom-
mended during mixing and application.
2. Remove all surface loaded fibers and dirt with a vacuum
cleaner as described above.
3. Thoroughly wet finned surfaces with clean water and a
low velocity garden hose, being careful not to bend fins.
4. Mix Totaline environmentally balanced coil cleaner in a
2-1/2 gallon garden sprayer according to the instructions
included with the cleaner. The optimum solution temperature
is 100°F.
NOTE: Do NOT USE water in excess of 130°F, as the enzy-
matic activity will be destroyed.
Top Panel
Center
Baffle
Support
(Field-
Supplied)
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in reduced unit
performance or unit shutdown.
High velocity water from a pressure washer or garden hose,
or compressed air should never be used to clean a coil. The
force of the water or air jet will bend the fin edges and
increase airside pressure drop.
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in accelerated
corrosion of unit parts.
Harsh chemicals, household bleach or acid or basic
cleaners should not be used to clean outdoor or indoor coils
of any kind. These cleaners can be very difficult to rinse out
of the coil and can accelerate corrosion at the fin/tube
interface where dissimilar materials are in contact. If there
is dirt below the surface of the coil, use the Totaline
environmentally balanced coil cleaner.

15
5. Thoroughly apply Totaline environmentally balanced coil
cleaner solution to all coil surfaces including finned area,
tube sheets and coil headers.
6. Hold garden sprayer nozzle close to finned areas and apply
cleaner with a vertical, up-and-down motion. Avoid spraying
in horizontal pattern to minimize potential for fin damage.
7. Ensure cleaner thoroughly penetrates deep into finned
areas. Interior and exterior finned areas must be thor-
oughly cleaned. Finned surfaces should remain wet with
cleaning solution for 10 minutes. Ensure surfaces are not
allowed to dry before rinsing. Reapply cleaner as needed
to ensure 10-minute saturation is achieved.
8. Thoroughly rinse all surfaces with low velocity clean
water using downward rinsing motion of water spray noz-
zle. Protect fins from damage from the spray nozzle.
Evaporator Coil
Cleaning the Evaporator Coil
1. Turn unit power off. Install lockout tag. Remove evapora-
tor coil access panel.
2. If economizer or two-position damper is installed, remove
economizer by disconnecting Molex®1 plug and removing
mounting screws.
3. Slide filters out of unit.
4. Clean coil using a commercial coil cleaner or dishwasher
detergent in a pressurized spray canister. Wash both sides
of coil and flush with clean water. For best results, back-
flush toward return-air section to remove foreign material.
Flush condensate pan after completion.
5. Reinstall economizer and filters.
6. Reconnect wiring.
7. Replace access panels.
Evaporator Coil Metering Devices
50FC-08-16 units with or without the Humidi-MiZer option use a
TXV-distributer system.
THERMOSTATIC EXPANSION VALVE (TXV)
All 50FC-08-16 units equipped with the Humidi-MiZer option
include TXV control. The TXV is a bi-flow, bleed port expansion
valve with an external equalizer. The TXVs are specifically
designed to operate with Puron®refrigerant. Use only factory-
authorized TXVs.
TXV Operation
The TXV is a metering device that is used in air conditioning and
heat pump systems to adjust to the changing load conditions by
maintaining a preset superheat temperature at the outlet of the
evaporator coil.
The volume of refrigerant metered through the valve seat is
dependent upon the following:
1. Superheat temperature is sensed by cap tube sensing bulb
on suction tube at outlet of evaporator coil. This tempera-
ture is converted into pressure by refrigerant in the bulb
pushing downward on the diaphragm, which opens the
valve using the push rods.
2. The suction pressure at the outlet of the evaporator coil is
transferred through the external equalizer tube to the under-
side of the diaphragm.
3. The pin is spring loaded, which exerts pressure on the under-
side of the diaphragm. Therefore, the bulb pressure works
against the spring pressure and evaporator suction pressure to
open the valve. If the load increases, the temperature
increases at the bulb, which increases the pressure on the top
side of the diaphragm. This opens the valve and increases the
flow of refrigerant. The increased refrigerant flow causes the
leaving evaporator temperature to decrease. This lowers the
pressure on the diaphragm and closes the pin. The refrigerant
flow is effectively stabilized to the load demand with negligi-
ble change in superheat.
Replacing TXV
1. Recover refrigerant.
2. Remove TXV support clamp using a 5/l6-in. nut driver.
3. Remove TXV using a wrench and an additional wrench on
connections to prevent damage to tubing.
4. Remove equalizer tube from suction line of coil. Use file
or tubing cutter to cut brazed equalizer line approximately
2 inches above suction tube.
5. Remove bulb from vapor tube inside cabinet.
6. Install the new TXV using a wrench and an additional
wrench on connections to prevent damage to tubing while
attaching TXV to distributor.
7. Attach the equalizer tube to the suction line. If the coil has a
mechanical connection, then use a wrench and an additional
wrench on connections to prevent damage. If the coil has a
brazed connection, use a file or a tubing cutter to remove the
mechanical flare nut from the equalizer line. Then use a new
coupling to braze the equalizer line to the stub (previous
equalizer line) in suction line.
8. Attach TXV bulb in the same location where the original (in
the sensing bulb indent) was when it was removed, using the
supplied bulb clamps. See Fig. 23 on page 16.
9. Route equalizer tube through suction connection opening
(large hole) in fitting panel and install fitting panel in place.
10. Sweat the inlet of TXV marked “IN” to the liquid line. Avoid
excessive heat which could damage the TXV valve. Use
quenching cloth when applying heat anywhere on TXV.
Refrigerant System Pressure Access Ports
There are two access ports in the system: on the suction tube near
the compressor and on the discharge tube near the compressor.
These are brass fittings with black plastic caps. The hose connec-
tion fittings are standard 1/4-in. SAE male flare couplings.
The brass fittings are two-piece high flow valves, with a recep-
tacle base brazed to the tubing and an integral spring-closed
check valve core screwed into the base. See Fig. 24. This check
valve is permanently assembled into this core body and cannot
be serviced separately; replace the entire core body if neces-
sary. Service tools are available from RCD that allow the re-
placement of the check valve core without having to recover
the entire system refrigerant charge. Apply compressor refrig-
erant oil to the check valve core’s bottom o-ring. Install the fit-
ting body with 96 ± 10 in.-lb (10.85 ± 1.1 Nm) of torque; do
not over-tighten.
1. Third-party trademarks and logos are the property of their respective
owners.

16
Fig. 23 — TXV Valve and Sensing Bulb Location
PURON (R-410A) REFRIGERANT
This unit is designed for use with Puron®(R-410A) refrigerant.
Do not use any other refrigerant in this system.
Puron (R-410A) refrigerant is provided in pink (rose) colored cyl-
inders. These cylinders are available with and without dip tubes;
cylinders with dip tubes will have a label indicating this feature.
For a cylinder with a dip tube, place the cylinder in the upright po-
sition (access valve at the top) when removing liquid refrigerant
for charging. For a cylinder without a dip tube, invert the cylinder
(access valve on the bottom) when removing liquid refrigerant.
Because Puron (R-410A) refrigerant is a blend, it is strongly rec-
ommended that refrigerant always be removed from the cylinder
as a liquid. Admit liquid refrigerant into the system in the dis-
charge line. If adding refrigerant into the suction line, use a com-
mercial metering/expansion device at the gauge manifold; remove
liquid from the cylinder, pass it through the metering device at the
gauge set and then pass it into the suction line as a vapor. Do not
remove Puron (R-410A) refrigerant from the cylinder as a vapor.
Refrigerant Charge
Amount of refrigerant charge is listed on the unit’s nameplate. Re-
fer to Carrier GTAC2-5 Charging, Recovery, Recycling and Rec-
lamation training manual and the following procedures.
Unit panels must be in place when unit is operating during the
charging procedure.
NO CHARGE
Use standard evacuating techniques. After evacuating system,
weigh in the specified amount of refrigerant.
LOW-CHARGE COOLING
Using Cooling Charging Charts, Fig. 25-29, vary refrigerant until
the conditions of the appropriate chart are met. Note the charging
charts are different from type normally used. Charts are based on
charging the units to the correct sub-cooling for the various operat-
ing conditions. Accurate pressure gauge and temperature sensing
device are required. Connect the pressure gauge to the service port
on the liquid line. Mount the temperature sensing device on the
liquid line and insulate it so that outdoor ambient temperature does
not affect the reading. Indoor-air cfm must be within the normal
operating range of the unit.
EXAMPLE:
Model 50FC*B08
Outdoor Temperature 85°F (29°C)
Suction Pressure 140 psig (965 kPa)
Suction Temperature should be 65°F (16°C)
USING COOLING CHARGING CHARTS
Take the outdoor ambient temperature and read the liquid pressure
gauge. Refer to chart to determine what liquid temperature should
be. If liquid temperature is low, add refrigerant. If liquid tempera-
ture is high, carefully recover some of the charge. Recheck the liq-
uid pressure as charge is adjusted.
Fig. 24 — CoreMax™1Access Port Assembly
VIEW WITH TXV BULB
INSULATION COVER REMOVED
TXV BULB
TXV BULB PROCESS TUBE
BULB CAPILLARY TUBE
SUCTION LINE
50FC SIZE DESIGNATION NOMINAL TONS REFERENCE
08 7.5
09 8.5
12 10.0
14 12.5
16 15.0
1. Third-party trademarks and logos are the property of their respective owners.
5/8" HEX 0.47
30°
0.596
1/2-20 UNF RH
1/2" HEX
45°
Washer
O-Ring
7/16-20 UNF RH
Depressor per AHRI 720
+.01/–.035
From Face of Body
This surface provides a metal to metal seal when
torqued into the seat. Appropriate handling is
required to not scratch or dent the surface.
SEAT CORE
(Part No. EC39EZ067)

17
COOLING CHARGING CHARTS
Fig. 25 — Cooling Charging Chart - 7.5 Ton
1034 1379 1723 2068 2413 2758 3102 3447 3792 4136
-6.7
4.4
15.5
26.6
37.7
48.8
59.9
20
40
60
80
100
120
140
150 200 250 300 350 400 450 500 550 600
Outdoor Coil Leaving Temperature (°C/°F)
Compressor Discharge Pressure (psig/kPa)
Remove Charge if Below the Curve
Add Charge if Above Curve
7.5 Ton Entry Tier R-410A Charging Chart
(Unit must have both compressors and
outdoor fans on high speed)
48TM006268 Rev. -

18
COOLING CHARGING CHARTS
Fig. 26 — Cooling Charging Chart - 8.5 Ton
1034 1379 1723 2068 2413 2758 3102 3447 3792 4136
-6.7
4.4
15.5
26.6
37.7
48.8
59.9
20
40
60
80
100
120
140
150 200 250 300 350 400 450 500 550 600
Outdoor Coil Leaving Temperature (°C/°F)
Compressor Discharge Pressure (psig/kPa)
Remove Charge if Below the Curve
Add Charge if Above Curve
8.5 Ton Entry Tier R-410A Charging Chart
(Unit must have both compressors and
outdoor fans on high speed)
48TM006269 Rev. -

19
COOLING CHARGING CHARTS
Fig. 27 — Cooling Charging Chart - 10 Ton
1034 1379 1723 2068 2413 2758 3102 3447 3792 4136
-6.7
4.4
15.5
26.6
37.7
48.8
59.9
20
40
60
80
100
120
140
150 200 250 300 350 400 450 500 550 600
Outdoor Coil Leaving Temperature (°C/°F)
Compressor Discharge Pressure (psig/kPa)
Remove Charge if Below the Curve
Add Charge if Above Curve
10 Ton Entry Tier R-410A Charging Chart
(Unit must have both compressors and
outdoor fans on high speed)
48TM006270 Rev. -

20
COOLING CHARGING CHARTS
Fig. 28 — Cooling Charging Chart - 12.5 Ton
1034 1379 1723 2068 2413 2758 3102 3447 3792 4136
-6.7
4.4
15.5
26.6
37.7
48.8
59.9
20
40
60
80
100
120
140
150 200 250 300 350 400 450 500 550 600
Outdoor Coil Leaving Temperature (°C/°F)
Compressor Discharge Pressure (psig/kPa)
Remove Charge if Below the Curve
Add Charge if Above Curve
12.5 Ton Entry Tier R-410A Charging Chart
(Unit must have both compressors and
outdoor fans on high speed)
48TM006271 Rev. -