Carrier 48JCH 04-06 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. 04-53480306-01 Printed in U.S.A. Form 48JCG-4-6-01SM Pg 1 11-23 Replaces: NEW
Service and Maintenance Instructions
CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 2
UNIT ARRANGEMENT AND ACCESS . . . . . . . . . . . . 3
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . 3
Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
SUPPLY FAN (BLOWER) SECTION . . . . . . . . . . . . . . 4
Supply Fan (Direct-Drive) . . . . . . . . . . . . . . . . . . . . . . 4
COOLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Condenser Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Condenser Coil Maintenance and Cleaning 
Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Evaporator Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
THERMOSTATIC EXPANSION VALVE (TXV) . . . . . 10
TXV Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Replacing TXV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Refrigerant System Pressure Access Ports . . . . . . 11
PURON (R-410A) REFRIGERANT . . . . . . . . . . . . . . . 12
Refrigerant Charge . . . . . . . . . . . . . . . . . . . . . . . . . . 12
COMPRESSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Replacing Compressor . . . . . . . . . . . . . . . . . . . . . . . 14
Compressor Rotation . . . . . . . . . . . . . . . . . . . . . . . . 14
Filter Drier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Condenser-Fan Adjustment . . . . . . . . . . . . . . . . . . . 14
Troubleshooting Cooling System . . . . . . . . . . . . . . 16
CONVENIENCE OUTLETS . . . . . . . . . . . . . . . . . . . . 17
Convenience Outlets . . . . . . . . . . . . . . . . . . . . . . . . 17
Installing Weatherproof Cover . . . . . . . . . . . . . . . . . 17
Non-Powered Type . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Unit-Powered Type . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Duty Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Fuse on Powered Type . . . . . . . . . . . . . . . . . . . . . . . 18
SMOKE DETECTORS . . . . . . . . . . . . . . . . . . . . . . . . 18
System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Smoke Detector Sensor . . . . . . . . . . . . . . . . . . . . . . 18
Smoke Detector Locations . . . . . . . . . . . . . . . . . . . . 19
Completing Installation of Return Air Smoke
Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
FIOP Smoke Detector Wiring and Response . . . . . 20
SENSOR AND CONTROLLER TESTS . . . . . . . . . . . 21
Sensor Alarm Test . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Controller Alarm Test . . . . . . . . . . . . . . . . . . . . . . . . 21
Dirty Controller Test . . . . . . . . . . . . . . . . . . . . . . . . . 21
Dirty Sensor Test . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Changing the Dirt Sensor Test . . . . . . . . . . . . . . . . .21
Remote Station Test . . . . . . . . . . . . . . . . . . . . . . . . .21
SD-TRK4 Remote Alarm Test Procedure . . . . . . . .22
Remote Test/Reset Station Dirty Sensor Test . . . .22
Dirty Sensor Test Using an SD-TRK4 . . . . . . . . . . .22
Detector Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
PROTECTIVE DEVICES . . . . . . . . . . . . . . . . . . . . . . .24
Compressor Protection . . . . . . . . . . . . . . . . . . . . . . .24
Relief Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Control Circuit, 24-V . . . . . . . . . . . . . . . . . . . . . . . . .24
GAS HEATING SYSTEM . . . . . . . . . . . . . . . . . . . . . .24
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Fuel Types and Pressures . . . . . . . . . . . . . . . . . . . .25
Combustion-Air Blower . . . . . . . . . . . . . . . . . . . . . . .25
Burners and Igniters . . . . . . . . . . . . . . . . . . . . . . . . .26
Burner Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Orifice Replacement . . . . . . . . . . . . . . . . . . . . . . . . .28
Troubleshooting Heating System . . . . . . . . . . . . . .30
SYSTEMVU CONTROL SYSTEM . . . . . . . . . . . . . . . .32
SystemVu Interface . . . . . . . . . . . . . . . . . . . . . . . . . .32
Air Temperature Sensors . . . . . . . . . . . . . . . . . . . . .32
Additional SystemVu Installation and
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . .32
COMPRESSOR VFD . . . . . . . . . . . . . . . . . . . . . . . . . .34
Drive Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Converter Board . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Filter Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Capacitor Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
ECONOMIZER SYSTEMS . . . . . . . . . . . . . . . . . . . . .42
EconoMi$er2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
PRE-START-UP/START-UP . . . . . . . . . . . . . . . . . . . .43
START-UP, GENERAL . . . . . . . . . . . . . . . . . . . . . . . .43
Unit Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Additional Installation/Inspection . . . . . . . . . . . . . .43
Gas Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Return-Air Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Outdoor-Air Inlet Screens . . . . . . . . . . . . . . . . . . . . .44
Compressor Mounting . . . . . . . . . . . . . . . . . . . . . . .44
Internal Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Refrigerant Service Ports . . . . . . . . . . . . . . . . . . . . .44
Compressor Rotation . . . . . . . . . . . . . . . . . . . . . . . .44
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Main Burner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Ventilation (Continuous Fan) . . . . . . . . . . . . . . . . . .45
FASTENER TORQUE VALUES . . . . . . . . . . . . . . . . .45
START-UP, SYSTEMVU CONTROLS . . . . . . . . . . . .45
48JC(G/H)*04-06 Single Package Rooftop
Ultra Low NOx (14 ng/J) Gas Heat/Electric Cooling Unit
with Puron®(R-410A) Refrigerant
3 to 5 Nominal Tons

2
APPENDIX A — MODEL NUMBER 
NOMENCLATURE. . . . . . . . . . . . . . . . . . . . . . . . . . 46
APPENDIX B — PHYSICAL DATA. . . . . . . . . . . . . . . 47
APPENDIX C — FAN PERFORMANCE . . . . . . . . . . . 51
APPENDIX D — WIRING DIAGRAMS . . . . . . . . . . . . 64
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . . CL-1
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, re-
pair, or service air-conditioning equipment. Untrained personnel
can perform 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.
WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury,
death and/or equipment damage.
R-410A refrigerant systems operate at higher pressures than
standard R-22 systems. Do not use R-22 service equipment or
components on R-410A refrigerant equipment.
WARNING
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in serious personal
injury, death, and/or property damage.
Disconnect gas piping from unit when leak testing at pressure
greater than 0.5 psig (3450 Pa). Pressures greater than 0.5 psig
(3450 Pa) will cause gas valve damage resulting in hazardous
condition. If gas valve is subjected to pressure greater than
0.5 psig (3450 Pa), it must be replaced before use. When
pressure testing field-supplied gas piping at pressures of
0.5 psig (3450 Pa) or less, a unit connected to such piping
must be isolated by closing the manual gas valve(s).
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.
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injury or
death.
Units with convenience outlet circuits may use multiple
disconnects. Check convenience outlet for power status before
opening unit for service. Locate its disconnect switch, if
appropriate, and open it. Lock-out and tag-out this switch, if
necessary.
IMPORTANT: Lockout/tag-out is a term used when electri-
cal power switches are physically locked preventing power to
the unit. A placard is placed on the power switch alerting ser-
vice personnel that the power is disconnected.

3
UNIT ARRANGEMENT AND ACCESS
General
Figures 1 and 2 show general unit arrangement and access
locations.
Fig. 1 — Typical Access Panel Locations
Fig. 2 — Blower Access Panel Location
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
Heating
• Heat exchanger flue passageways cleanliness
• Gas burner condition
• Gas manifold pressure
• Heating temperature rise
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 re-
placed 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. 3).
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. 3).
Filter Access Panel
Outdoor-Air Opening and
Indoor Coil Access Panel
Compressor
Access Panel
Blower
Access
Panel
Flue Opening
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
Fig. 3 — 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. 4).
Fig. 4 — 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
All low-voltage wiring should be routed through the provided
raceway built into the corner post of the unit or secured to the
unit control box with the electrical conduit in order to provide
UL-required clearance between high and low-voltage wiring.
Supply Fan (Direct-Drive)
All JC units have the EcoBlue™ direct drive vane axial fan
system. The fan is driven by an ECM motor with speed that is
user set through the Unit Control Board (UCB). Speeds are ful-
ly configurable from 40% to 100% of motor’s maximum speed
(see Fig. 5 and 6).
Fig. 5 — Direct-Drive Supply Fan Assembly
Fig. 6 — ECM Motor Plug Connectors
17-1/4"
Divider
Barometric
Relief
Cleanable
Aluminum
Filter Filter
Hood
Filter
Clip
Outside
Air
Screws
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.
Motor
Plug
Fan
Rotor
ECM
Motor
321
654
987
BLUE
YELLOW
BLACK
GRN/YEL
ORANGE
GRAY
Power L3 (3 phase only)
Power L2
Power L1
Earth Ground
WHITE CTL Signal Common
10 vdc Source
0–10 vdc Signal

5
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
specification CFM (cubic feet per minute) and ESP (external
static pressure) required, and per the Fan speed set up label in-
cluded 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 voltage setting was filled in and if so, set
fan speed to that voltage. Otherwise see the following detailed
instructions.
NOTE: Fan Speed Set-Up 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 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. 7), 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 the label.
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. 7). 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 48JC-04-06 Series Single Package
Rooftop Units with SystemVu Controller Controls, Start-up,
Operation and Troubleshooting manual.
NOTE: Values in the Field Accessories section are RPM adders.
Fig. 7 — Example of Fan Speed Set Up Labels for SystemVu™ Controls
Field Accessories:
2500
Economizer
ESP in. wg
RPM Calculator
CFM
0.2
1425
1512
1601
1692
1784
1878
1973
2069
2166
1500
1625
1750
1875
2000
2125
2250
2375
65
0.4
1609
1688
1768
1850
1933
2018
2104
2192
2282
65
0.6
1764
1839
1916
1994
2073
2153
2235
2317
0.8
1902
1974
2047
2123
2200
2277
2356
65
1.0
2028
2097
2168
2241
2316
65
1.2
2147
2212
2280
2351
65
1.4
2260
2322
2387
65
1.6 1.8 2.0
2367
65 65
UNIT MODEL NUMBER
FAN SPEED SETUP (RPM)
MAIN MENU:
DETERMINE RPM FROM BELOW
UNIT CONFIGURATIONS
INDOOR FAN
IDF VENT SPD -RPM
IDF HEAT SPD -RPM
IDF LOW COOL SPD -RPM
IDF HIGH COOL SPD -RPM
IDF FREE COOL SPD -RPM
SETTINGS
48TC003136 REV. A

6
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. For temperature related faults the motor re-
quires a line voltage reset to continue operation. For all others,
the motor will resume operation automatically as soon as the
fault condition is cleared. See Table 1 for a complete list.
Table 1 — Fault Condition/Reset Trigger
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 IFM on Unit Control Board (UCB) (see Fig. 8).
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 assembly
and replace the motor with one having the same part number.
Do not substitute with an alternate design motor as the volt-
age/speed programming will not be the same as that on an
original factory motor.
Fig. 8 — Supply Fan Control Wiring Diagram
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. 9.
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 two 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. 9 — Fan Assembly Removal
Disassembling Motor and Fan Assembly
See Fig. 10.
1. Remove six screws from retaining rings in the top of the
fan rotor.
2. Remove rotor from motor.
3. Remove four screws connecting motor to stator flange.
4. Remove stator from motor.
5. If required, remove stator limit switch on aluminum stator.
6. Remove three screws from the heat shield. Retain the heat
shield if a new heat shield has not been ordered.
Fault
Condition
Reset
Trigger Description
Phase Failure Automatic
One phase is missing or imbalanced. In
this case the motor will come to a stop
and then automatically restart when all
phases are present.
Locked/
Blocked Rotor Automatic
The rotor is blocked. Once the locking
mechanism has been removed, the
motor will automatically restart.
Motor Over
Heated Manual
The motor will stop in the event the
motor over heats. In this case there has
to be a manual restart.
Power Module
Over Heated Manual
The motor will stop in the event the
electronics over heat. In this case there
has to be a manual restart.
Line under-
voltage Automatic
Once the line voltage returns within
permitted operating range, the fan will
automatically restart.
Communication
Error Automatic
Internal communication error of the
fan’s electronics. The fan will restart
automatically, if error is cleared.
48JC Unit Voltage Motor Voltage Min-Max Volts
208/230 230 187-253
460 460 414-506
4
2
1
3

7
Fig. 10 — Disassembling Motor and Fan Assembly
Reassembly of Motor and Fan Assembly
See Fig.11.
1. Install heat shield on motor with three #8-32 x 3/8-in.
thread cutting screws (P/N: AK92AB100). Tighten to
30 in.-lb (3.39 Nm).
2. Place motor on flat surface.
3. If required, install stator limit switch on aluminum stator with
two #10 x 5/8-in. hex head screws (P/N: AL48AM217).
Tighten to 50 in.-lb (5.65 Nm).
4. If required, insert composite ring into aluminum stator
where pegs match up with holes.
5. Line up rectangle key way in the center of stator with rect-
angle feature on motor and set stator onto motor.
6. Install four #10-32 x 1/2-in. hex head machine screws
(P/N: AD07AB126) to connect aluminum stator to
motor. Tighten to 23 in.-lb (2.6 Nm).
7. Fit grommet on motor wire harness into keyhole feature on
the side of the stator and pull wire harness out through
grommet.
8. Install rotor on motor by lining up one of 9 holes on com-
posite rotor with one of 9 holes on motor flange. This can
be done by adjusting motor and the top of the motor hub
and aligning using a 3/16-in. Allen key or similar pin.
Press fan rotor down until it is flush with the motor flange.
9. Set retaining rings (x3) into composite rotor and install
6 #10-32 x 1/2-in. hex head machine screws (P/N:
AD07AB126) through the holes in retaining rings. Tighten
to 23 in.-lbs (2.6 Nm). It is recommended this screw
installation be done in a star pattern.
10. Align tabs of composite casing with rectangular cutouts on
top of aluminum stator and snap into place.
11. Final assembly should have a small clearance between top of
plastic rotor and underside of casing lip. Spin rotor by hand to
ensure no contact or rubbing between these two parts.
Fig. 11 — Fan System Re-Assembly
1
2
3
4
6
5
2
10
8
6
3
9
4
1
77
5

8
Reinstalling Motor and Fan Assembly
See Fig. 12.
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 2 #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. 12 — Fan Assembly Installation
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 water rinse.
PERIODIC CLEAN WATER RINSE
A periodic clean water rinse is very beneficial for coils that are
applied in coastal or industrial environments. However, it is very
important that the water rinse is made with a very low velocity
water stream to avoid damaging the fin edges. Monthly cleaning
as described below is recommended. Rinsing coils in the oppo-
site direction 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.
WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury,
death and/or equipment damage.
This system uses R-410A 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 R-410A
refrigerant. If unsure about equipment, consult the equipment
manufacturer.
1
3
4
2

9
Two-Row Condenser Coils
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. 13).
Fig. 13 — Location of Screws and Coil Corner Post
3. Lift and rotate the top panel at the condenser fan end and
rotate the panel 90 degrees. Support the top panel so it
remains level while resting on the condenser fan as shown
in Fig. 14.
Fig. 14 — Top Panel Position
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 upper and lower
coil retaining clips on the hairpin end of the coil tube
sheets (see Fig. 15).
6. Remove the upper and lower retaining clips.
Fig. 15 — 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. 16).
9. Clean the outer coil surface to remove surface loaded fibers
or dirt. See “Remove Surface Loaded Fibers” on page 8 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 lower
and upper coil clips. Reinstall the top panel and replace all
screws.
Fig. 16 — Separating Coil Sections
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
Top Panel
Center
Baffle
Compressor
Access
Panel
Support
(Field-
Supplied)
Coil Clips
4" max.
(102 mm)
Inner
Coil
Section
Outer
Coil
Section
Condenser
Coil
Center Baffle
Hairpin
End
Top View
Spacer
(Field-Supplied)

10
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 tempera-
ture is 100°F.
NOTE: DO NOT USE water in excess of 130°F, as the enzy-
matic activity will be destroyed.
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
nozzle. 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.
THERMOSTATIC EXPANSION VALVE (TXV)
All 48JC(G/H) units include a factory-installed, non-adjustable
thermostatic expansion valve (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®refriger-
ant. 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 de-
pendent 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
underside of the diaphragm.
3. The pin is spring loaded, which exerts pressure on the
underside 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 tem-
perature 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 negligible change in superheat.
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.
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 environmentally balanced coil
cleaner.
1. Third-party trademarks and logos are the property of their respective
owners.

11
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 addi-
tional 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. 17).
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.
Fig. 17 — TXV Valve and Sensing Bulb Location
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 receptacle
base brazed to the tubing and an integral spring-closed check
valve core screwed into the base (see Fig. 18). This check valve is
permanently assembled into this core body and cannot be serviced
separately; replace the entire core body if necessary. Service tools
are available from RCD that allow the replacement of the check
valve core without having to recover the entire system refrigerant
charge. Apply compressor refrigerant oil to the check valve core’s
bottom o-ring. Install the fitting body with 96 ± 10 in.-lb
(10.85 ± 1.10 Nm) of torque; do not over-tighten.
Fig. 18 — CoreMax™1Access Port Assembly
TXV Sensing Bulb
Clamp
Thermostatic
Expansion
Valve (TXV)
NOTE: Sensing bulb insulation removed for clarity.
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)

12
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. 19-24, 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 48JC(G/H)*B04
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.
COOLING CHARGING CHARTS
Fig. 19 — Cooling Charging Chart - 3 Ton
Fig. 20 — Cooling Charging Chart - 3 Ton with
Humidi-MiZer®System Option
48JC(G/H) SIZE
DESIGNATION NOMINAL TONS REFERENCE
04 3
05 4
06 5
Outdoor Coil Leaving Temperature, [°C/°F]
1034 1379 1723 2068 2413 2758 3102 3447 3792 4136
-6.6
4.5
15.6
26.7
37.8
48.9
60.0
20
40
60
80
100
120
140
150 200 250 300 350 400 450 500 550 600
Compressor Discharge Pressure, [psig/Kpa]
48TC004277 REV -
Add Charge if Above the Curve
3 Ton JC
R-410A Refrigerant Charging Chart
(Unit must be put in Test Mode and set the Cooling test
compressor speed to 4400)
Remove Charge if Below the
Curve
1034 1379 1723 2068 2413 2758 3102 3447 3792 4136
-6.6
4.5
15.6
26.7
37.8
48.9
60.0
20
40
60
80
100
120
140
150 200 250 300 350 400 450 500 550 600
Compressor Discharge Pressure, [psig/Kpa]
3 Ton JC Humidimizer
R-410A Refrigerant Charging Chart
(Unit must be put in Test Mode and set the Humidimizer test
compressor speed to 4400)
Remove Charge if Below the
Curve
48TC004274 REV -
Add Charge if Above the Curve
Outdoor Coil Leaving Temperature, [°C/°F]

13
Fig. 21 — Cooling Charging Chart - 4 Ton
Fig. 22 — Cooling Charging Chart - 4 Ton with
Humidi-MiZer®System Option
Fig. 23 — Cooling Charging Chart - 5 Ton
Fig. 24 — Cooling Charging Chart - 5 Ton with
Humidi-MiZer®System Option
1034 1379 1723 2068 2413 2758 3102 3447 3792 4136
-6.6
4.5
15.6
26.7
37.8
48.9
60.0
20
40
60
80
100
120
140
150 200 250 300 350 400 450 500 550 600
Compressor Discharge Pressure, [psig/Kpa]
4 Ton JC
R-410A Refrigerant Charging Chart
(Unit must be put in Test Mode and set the Cooling test compressor
speed to 4500)
Remove Charge if Below the
Curve
48TC004276 REV -
Add Charge if Above the Curve
Outdoor Coil Leaving Temperature, [°C/°F]
1034 1379 1723 2068 2413 2758 3102 3447 3792 4136
-6.6
4.5
15.6
26.7
37.8
48.9
60.0
20
40
60
80
100
120
140
150 200 250 300 350 400 450 500 550 600
Compressor Discharge Pressure, [psig/Kpa]
4 Ton JC Humidimizer
R-410A Refrigerant Charging Chart
(Unit must be put in Test Mode and set the Humidimizer test
compressor speed to 4500)
Remove Charge if Below the
Curve
48TC004273 REV -
Add Charge if Above the Curve
Outdoor Coil Leaving Temperature, [°C/°F]
1034 1379 1723 2068 2413 2758 3102 3447 3792 4136
-6.6
4.5
15.6
26.7
37.8
48.9
60.0
20
40
60
80
100
120
140
150 200 250 300 350 400 450 500 550 600
Compressor Discharge Pressure, [psig/Kpa]
5 Ton JC
R-410A Refrigerant Charging Chart
(Unit must be put in Test Mode and set the Cooling test compressor
speed to 4100)
Remove Charge if Below the
Curve
48TC004275 REV -
Add Charge if Above the Curve
Outdoor Coil Leaving Temperature, [°C/°F]
1034 1379 1723 2068 2413 2758 3102 3447 3792 4136
-6.6
4.5
15.6
26.7
37.8
48.9
60.0
20
40
60
80
100
120
140
150 200 250 300 350 400 450 500 550 600
Compressor Discharge Pressure, [psig/Kpa]
5 Ton JC Humidimizer
R-410A Refrigerant Charging Chart
(Unit must be put in Test Mode and set the Humidimizer test
compressor speed to 4100)
Remove Charge if Below the
Curve
48TC004272 REV -
Add Charge if Above the Curve
Outdoor Coil Leaving Temperature, [°C/°F]

14
COMPRESSOR
Lubrication
The compressor is charged with the correct amount of oil at the
factory.
Replacing Compressor
NOTE: Only factory-trained service technicians should remove
and replace compressor units.
Compressor Rotation
NOTE: When the compressor is rotating in the wrong direc-
tion, the unit makes an elevated level of noise and does not
provide cooling.
On 3-phase units with scroll compressors, it is important to be cer-
tain compressor is rotating in the proper direction. To determine
whether or not compressor is rotating in the proper direction:
1. Connect service gauges to suction and discharge pressure
fittings.
2. Energize the compressor.
3. The suction pressure should drop and the discharge pres-
sure should rise, as is normal on any start-up.
NOTE: If the suction pressure does not drop and the dis-
charge pressure does not rise to normal levels, the evaporator
fan is probably also rotating in the wrong direction.
4. Turn off power to the unit.
5. Reverse any two of the three unit power leads.
6. Reapply electrical power to the compressor. The suction
pressure should drop and the discharge pressure should
rise which is normal for scroll compressors on start-up.
7. Replace compressor if suction/discharge pressures are not
within specifications for the specific compressor.
The suction and discharge pressure levels should now move to
their normal start-up levels.
Filter Drier
Replace whenever refrigerant system is exposed to atmosphere.
Only use factory specified liquid-line filter driers with working
pressures no less than 650 psig. Do not install a suction-line filter
drier in liquid line. A liquid-line filter drier designed for use with
Puron refrigerant is required on every unit.
Condenser-Fan Adjustment
1. Shut off unit power supply. Install lockout tag.
2. Remove condenser-fan assembly (grille, motor, and fan)
(see Fig. 25).
3. Loosen fan hub setscrews.
4. Adjust fan height by pushing fan until it stops on the fan
shaft.
5. Tighten set screw to 60 in.-lb (6.78 Nm).
6. Replace condenser-fan assembly. When replacing the con-
denser-fan assembly follow the screw pattern sequence
shown in Fig. 26. The screws must be replaced in the
sequence shown in the figure.
Fig. 25 — Condenser Fan Adjustment
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in damage to
components.
The compressor is in a R-410A refrigerant system and uses a
polyolester (POE) oil. This oil is extremely hygroscopic,
meaning it absorbs water readily. POE oils can absorb
15 times as much water as other oils designed for HCFC and
CFC refrigerants. Avoid exposure of the oil to the atmosphere.
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
INSTALLATION SITE DAMAGE
Failure to follow this caution can result in damage to
equipment location site.
R-410A refrigerant contains polyolester (POE) oil that can
damage the roof membrane. Caution should be taken to
prevent POE oil from spilling onto the roof surface.
The factory also recommends that the suction and discharge
lines be cut with a tubing cutter instead of using a torch to
remove brazed fittings.
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution can result in premature wear and
damage to equipment.
Scroll compressors can only compress refrigerant if
rotating in the right direction. Reverse rotation for
extended times can result in internal damage to the
compressor. Scroll compressors are sealed units and
cannot be repaired on site location.

15
Fig. 26 — Condenser-Fan Assembly — Screw Pattern Sequence
1
2
3
4
5
No Screw
(Blank Tab)

16
Troubleshooting Cooling System
Refer to Table 2 for additional troubleshooting topics.
Table 2 — Troubleshooting
SYMPTOM CAUSE SOLUTION
Compressor and Outdoor
Fan Will Not Start
Power failure. Call power company.
Fuse blown or circuit breaker tripped. Replace fuse or reset circuit breaker. Determine root cause.
Defective thermostat, contactor, transformer.
control relay, or capacitor. Replacement component.
Insufficient line voltage. Determine cause and correct.
Incorrect or faulty wiring. Check wiring diagram and rewire correctly.
Thermostat setting too high. Lower thermostat setting below room temperature.
High pressure switch tripped. See problem “Excessive head pressure.”
Low pressure switch tripped. Check system for leaks. Repair as necessary.
Freeze-up protection thermostat tripped. See problem “Suction pressure too low.”
Compressor Will Not Start
but Outdoor Fan Runs
Faulty wiring or loose connections in compressor
circuit. Check wiring and repair or replace.
Compressor motor burned out, seized, or internal
overload open.
Determine cause. Replace compressor or allow enough time for
internal overload to cool and reset.
Defective run/start capacitor, overload, start
relay.
Determine cause. Replace compressor or allow enough time for
internal overload to cool and reset.
One leg of 3-phase power dead. Replace fuse or reset circuit breaker. Determine cause.
Compressor Cycles (Other
Than Normally Satisfying
Thermostat)
Refrigerant overcharge or undercharge. Recover refrigerant, evacuate system, and recharge to nameplate.
Defective compressor. Replace and determine cause.
Insufficient line voltage. Determine cause and correct.
Blocked outdoor coil or dirty air filter. Determine cause and correct.
Defective Run/Start capacitor, overload, start
relay. Determine cause and correct.
Defective thermostat. Replace thermostat.
Faulty outdoor-fan (cooling) or indoor-fan
(heating) motor or capacitor. Replace faulty part.
Restriction in refrigerant system. Locate restriction and remove.
Defective loader plug. Determine cause and replace.
Compressor Operates
Continuously
Dirty air filter. Replaced filter.
Unit undersized for load. Decrease load or increase unit size.
Thermostat set too low (cooling). Reset thermostat.
Low refrigerant charge. Locate leak; repair and recharge.
Air in system. Recover refrigerant, evacuate system, and recharge.
Outdoor coil dirty or restricted. Clean coil or remove restriction.
Compressor Makes
Excessive Noise Compressor rotating in the wrong direction. Reverse the 3-phase power leads as described in Start-Up.
Excessive Head Pressure
Dirty outside. Replace filter.
Dirty outdoor coil (cooling). Clean coil.
Refrigerant overcharged. Recover excess refrigerant.
Air in system. Recover refrigerant, evacuate system, and recharge.
Condensing air restricted or air short-cycling. Determine cause and correct.
Head Pressure Too Low
Low refrigerant charge. Check for leaks; repair and recharge
Compressor scroll plates defective. Replace compressor
Restriction in liquid tube. Remove restriction.
Excessive Suction Pressure
High heat load. Check for source and eliminate.
Compressor scroll plates defective. Replace compressor.
Refrigerant overcharge. Recover excess refrigerant.
Suction Pressure Too Low
Dirty air filter (cooling). Replace filter.
Dirt or heavily iced outdoor coil (heating). Clean outdoor coil. Check defrost cycle operation.
Low refrigerant charge. Check for leaks; repair and recharge.
Metering device or low side restricted Remove source of restriction.
Insufficient indoor airflow (cooling mode). Increase air quantity. Check filter and replace if necessary.
Temperature too low in conditioned area. Reset thermostat.
Field-installed filter drier restricted. Replace.
Outdoor ambient temperature below 40°F
(cooling). Install low-ambient kit.
Outdoor fan motor(s) not operating (heating). Check fan motor operation.

17
CONVENIENCE OUTLETS
Convenience Outlets
Two types of convenience outlets are offered on 48JC(G/H) mod-
els: non-powered and unit-powered. Both types provide a 125-vac
ground-fault circuit-interrupt (GFCI) duplex receptacle rated at
15A behind a hinged waterproof access cover, located on the end
panel of the unit (see Fig. 27).
Fig. 27 — Convenience Outlet Location
Installing Weatherproof Cover
A weatherproof while-in-use cover for the factory installed conve-
nience outlets is now required by UL standards. This cover cannot
be factory-mounted due to its depth. The cover must be installed at
unit installation. For shipment, the convenience outlet is covered
with a blank cover plate.
The weatherproof cover kit is shipped in the unit’s control box.
The kit includes the hinged cover, a backing plate and gasket.
NOTE: DISCONNECT ALL POWER TO UNIT AND CONVE-
NIENCE OUTLET. Use approved lockout/tag-out procedures.
1. Remove the blank cover plate at the convenience outlet;
discard the blank cover.
2. Loosen the two screws at the GFCI duplex outlet, until
approximately 1/2-in. (13 mm) under screw heads is
exposed.
3. Press the gasket over the screw heads. Slip the backing
plate over the screw heads at the keyhole slots and align
with the gasket; tighten the two screws until snug (do not
over-tighten).
4. Mount the weatherproof cover to the backing plate as
shown in Fig. 28.
5. Remove two slot fillers in the bottom of the cover to per-
mit service tool cords to exit the cover.
6. Check cover installation for full closing and latching.
Fig. 28 — Weatherproof Cover Installation
Non-Powered Type
This type requires the field installation of a general-purpose 125-v
15-A circuit powered from a source elsewhere in the building. Ob-
serve national and local codes when selecting wire size, fuse or
breaker requirements and disconnect switch size and location.
Route 125-v power supply conductors into the bottom of the utili-
ty box containing the duplex receptacle.
Unit-Powered Type
A unit-mounted transformer is factory-installed to step-down the
main power supply voltage to the unit to 115-v at the duplex re-
ceptacle. This option also includes a manual switch with fuse, lo-
cated in a utility box and mounted on a bracket behind the conve-
nience outlet; access is through the unit’s control box access panel
(see Fig. 27).
The primary leads to the convenience outlet transformer are not
factory-connected. Selection of primary power source is a custom-
er option. If local codes permit, the transformer primary leads can
be connected at the line-side terminals on a unit-mounted non-
fused disconnect or Heating, Air Conditioning and Refrigeration
(HACR) breaker switch; this will provide service power to the
unit when the unit disconnect switch or HACR switch is open.
Other connection methods will result in the convenience outlet cir-
cuit being de-energized when the unit disconnect or HACR switch
is open (see Fig. 29).
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injury or
death.
Units with convenience outlet circuits may use multiple
disconnects. Check convenience outlet for power status before
opening unit for service. Locate its disconnect switch, if
appropriate, and open it. Lock-out and tag-out this switch, if
necessary.
Convenience
Outlet GFCI PWD-CO Fuse
Switch
PWD-CO
Transformer
Cover — While-In-Use
Weatherproof
Baseplate For
GFCI Receptacle
Gasket
GFCI Receptacle
Not Included
TOP
TOP
TOP
WET LOCA
TIONS
WETLOCATIONS

18
Fig. 29 — Powered Convenience Outlet Wiring
Duty Cycle
The unit-powered convenience outlet has a duty cycle limitation.
The transformer is intended to provide power on an intermittent
basis for service tools, lamps, etc; it is not intended to provide 15A
loading for continuous duty loads (such as electric heaters for
overnight use). Observe a 50% limit on circuit loading above 8A
(i.e., limit loads exceeding 8A to 30 minutes of operation every
hour).
Maintenance
Periodically test the GFCI receptacle by pressing the TEST button
on the face of the receptacle. This should cause the internal circuit
of the receptacle to trip and open the receptacle. Check for proper
grounding wires and power line phasing if the GFCI receptacle
does not trip as required. Press the RESET button to clear the
tripped condition.
Fuse on Powered Type
The factory fuse is a Bussmann Fusetron1T-15, non-renewable
screw-in (Edison base) type plug fuse.
USING UNIT-MOUNTED CONVENIENCE OUTLETS
Units with unit-mounted convenience outlet circuits will often re-
quire that two disconnects be opened to de-energize all power to
the unit. Treat all units as electrically energized until the conve-
nience outlet power is also checked and de-energization is con-
firmed. Observe National Electrical Code Article 210, Branch Cir-
cuits, for use of convenience outlets.
SMOKE DETECTORS
Smoke detectors are available as factory-installed options on
48JC(G/H) models. Smoke detectors may be specified for sup-
ply air only, for return air without or with economizer, or in com-
bination of supply air and return air. Return air smoke detectors
are arranged for vertical return configurations only. All compo-
nents necessary for operation are factory-provided and mounted.
The unit is factory-configured for immediate smoke detector
shutdown operation; additional wiring or modifications to unit
terminal board may be necessary to complete the unit and smoke
detector configuration to meet project requirements.
System
The smoke detector system consists of a four-wire controller and
one or two sensors. Its primary function is to shut down the roof-
top unit in order to prevent smoke from circulating throughout
the building. It is not to be used as a life saving device.
Controller
The controller (see Fig. 30) includes a controller housing, a print-
ed circuit board, and a clear plastic cover. The controller can be
connected to one or two compatible duct smoke sensors. The clear
plastic cover is secured to the housing with a single captive screw
for easy access to the wiring terminals. The controller has three
LEDs (for Power, Trouble and Alarm) and a manual test/reset but-
ton (on the cover face).
Smoke Detector Sensor
The smoke detector sensor (see Fig. 31) includes a plastic housing,
a printed circuit board, a clear plastic cover, a sampling tube inlet
and an exhaust tube. The sampling tube (when used) and exhaust
tube are attached during installation. The sampling tube varies in
length depending on the size of the rooftop unit. The clear plastic
cover permits visual inspections without having to disassemble
the sensor. The cover attaches to the sensor housing using four
captive screws and forms an airtight chamber around the sensing
electronics. Each sensor includes a harness with an RJ45 terminal
for connecting to the controller. Each sensor has four LEDs (for
Power, Trouble, Alarm and Dirty) and a manual test/reset button
(on the left-side of the housing).
Fig. 30 — Controller Assembly
1. Third-party trademarks and logos are the property of their respective
owners.
UNIT
VOLTAGE
CONNECT
AS
PRIMARY
CONNECTIONS
TRANSFORMER
TERMINALS
208, 230 240 L1: RED +YEL
L2: BLU + GRA
H1 + H3
H2 + H4
460 480
L1: RED
Splice BLU + YEL
L2: GRA
H1
H2 + H3
H4
575 600 L1: RED
L2: GRA
H1
H2
Duct Smoke Sensor
Controller
Conduit Nuts
(Supplied by Installer)
Conduit Support Plate
Terminal Block Cover
Cover Gasket
(Ordering Option)
Controller
Cover
Fastener (x2)
Conduit Couplings
(Supplied by Installer)
Controller
Housing
and Electronics
Alarm
Trouble
Power
Test/Reset
Switch

19
Air is introduced to the duct smoke detector sensor’s sensing
chamber through a sampling tube that extends into the HVAC duct
and is directed back into the ventilation system through a (shorter)
exhaust tube.
The difference in air pressure between the two tubes pulls the sam-
pled air through the sensing chamber. When a sufficient amount of
smoke is detected in the sensing chamber, the sensor signals an
alarm state and the controller automatically takes the appropriate
action to shut down fans and blowers, change over air handling
systems, notify the fire alarm control panel, etc.
The sensor uses a process called differential sensing to prevent
gradual environmental changes from triggering false alarms. A
rapid change in environmental conditions, such as smoke from a
fire, causes the sensor to signal an alarm state but dust and debris
accumulated over time does not.
The difference in air pressure between the two tubes pulls the sam-
pled air through the sensing chamber. When a sufficient amount of
smoke is detected in the sensing chamber, the sensor signals an
alarm state and the controller automatically takes the appropriate
action to shut down fans and blowers, change over air handling
systems, notify the fire alarm control panel, etc.
For installations using two sensors, the duct smoke detector
does not differentiate which sensor signals an alarm or trouble
condition.
Fig. 31 — Smoke Detector Sensor
Smoke Detector Locations
SUPPLY AIR
The supply air smoke detector sensor is located to the right of
the unit’s indoor (supply) fan (see Fig. 32). Access is through
the fan access panel. The sampling tube inlet extends through
the fan deck (into a high pressure area). The controller is locat-
ed on a bracket to the right of the return filter, accessed through
the lift-off filter panel.
Fig. 32 — Typical Supply Air Smoke Detector Sensor
Location
RETURN AIR SMOKE DETECTOR SENSOR WITHOUT
ECONOMIZER
The sampling tube is located across the return air opening on the
unit basepan (see Fig. 33). The holes in the sampling tube face
downward, into the return air stream. The sampling tube is con-
nected through tubing to the return air sensor that is mounted on
a bracket high on the partition between return filter and control-
ler location. The sensor is shipped in a flat-mounting location.
Installation requires that this sensor be relocated to its operating
location and the tubing to the sampling tube be connected. See
“Completing Installation of Return Air Smoke Detector” on
page 20.
Fig. 33 — Typical Return Air Smoke Detector
Location
See
Detail A
Detail A
Plug
Sampling Tube
(Covered Separately)
Coupling
Magnetic
Test/Reset
Switch
Alarm
Trouble
Power
Dirty
Sensor
Cover
Cover Gasket
(Ordering Option)
Sensor Housing and Electronics
Exhaust Gasket
Exhaust Tube
Duct Smoke Sensor
Intake
Gasket
TSD-CO2
(Ordering Option)
Supply Air
Smoke Detector
Return Air
Smoke Detector
(As Shipped)

20
RETURN AIR SMOKE DETECTOR SENSOR WITH
ECONOMIZER
The sampling tube is inserted through the side plates of the econo-
mizer housing, placing it across the return air opening on the unit
basepan (see Fig. 34). The holes in the sampling tube face down-
ward, into the return air stream. The sampling tube is connected
using tubing to the return air sensor mounted on a bracket high on
the partition between return filter and controller location. The sen-
sor is shipped in a flat-mounting location. Installation requires the
sensor be relocated to its operating location and the tubing to the
sampling tube be connected. See “Completing Installation of Re-
turn Air Smoke Detector” below.
Fig. 34 — Return Air Sampling Tube Location (View
reoriented to show opposite side for clarity.)
Completing Installation of Return Air Smoke
Detector
Use the following steps to complete the installation of the return
air smoke detector.
1. Unscrew the two screws holding the return air sensor detector
plate (see Fig. 35). Save the screws.
2. Remove the return air smoke sensor module and its detector
plate.
Fig. 35 — Return Air Smoke Detector
Shipping Position
Fig. 36 — Return Air Smoke Detector
Operating Position
3. Rotate the detector plate so the sensor is facing outwards
and the sampling tube connection is on the bottom (see
Fig. 36).
4. Screw the sensor and detector plate into its operating position
using screws from Step 1. Ensure the sampling tube connec-
tion is on the bottom and the exhaust tube is on the top.
5. Connect the flexible tube on the sampling inlet to the sam-
pling tube on the basepan.
6. For units with an economizer, the sampling tube is inte-
grated into the economizer housing but connecting the
flexible tubing to the sampling tube is the same.
FIOP Smoke Detector Wiring and Response
SYSTEMVU™ UNITS
See Fig. 37 for typical SystemVu controller smoke detector wiring
Highlight A
Smoke detector NC contact set will open on smoke alarm condi-
tion, de-energizing the ORN conductor.
Highlight B – Using Remote Logic (SystemVu Controller)
Six conductors are provided for field use (see Highlight B) for ad-
ditional annunciation functions.
Fig. 37 — Typical Smoke Detector System Wiring,
SystemVu Control Units.
Return Air
Sampling Tube
Sample Tube
Screws
Flexible Exhaust Tubes
Return Air Smoke Detector
(Operating Position Shown)
Screws (2)
Sample Tube
Controller
Module
AA
B