Carrier 48TC 04 Series Installation and user guide

Service and Maintenance Instructions
48TC**04 --- 16
Nominal 3 to 15 Tons
with Puron(R---410A) Refrigerant
TABLE OF CONTENTS
SAFETY CONSIDERATIONS 1....................
UNIT ARRANGEMENT AND ACCESS 3...........
ROUTINE MAINTENANCE 3.....................
SUPPLY FAN (BLOWER) SECTION 6..............
STAGED AIR VOLUME CONTROL (SAV) -- 2 SPEED
FAN WITH VARIABLE FREQUENCY
DRIVE (VFD) 7.................................
ADDITIONAL VARIABLE FREQUENCY DRIVE
(VFD) INSTALLATION AND TROUBLESHOOTING. 8
SUPPLY FAN MOTOR 8..........................
COOLING 10...................................
EVAPORATOR COIL METERING DEVICES 13......
PURONR(R--410A) REFRIGERANT 16.............
COOLING CHARGING CHARTS 21................
COMPRESSOR 34...............................
CONVENIENCE OUTLETS 36....................
SMOKE DETECTORS 37.........................
SENSOR AND CONTROLLER TESTS 41...........
INDICATORS 43................................
PROTECTIVE DEVICES 44.......................
GAS HEATING SYSTEM 45......................
PREMIERLINKCONTROL 62...................
RTU--OPEN CONTROL SYSTEM 62................
SENSORY/ACCESSORY INSTALLATION 63........
HUMIDI--MIZER ADAPTIVE DEHUMIDIFICATION
SYSTEM 64....................................
ECONOMIZER SYSTEMS 78.....................
PRE--START--UP 87..............................
START--UP, GENERAL 87........................
START--UP, PREMIERLINKCONTROLS 90.......
START--UP, RTU--OPEN CONTROLS 90............
FASTENER TORQUE VALUES 90.................
APPENDIX I. PHYSICAL DATA 91................
APPENDIX II. FAN PERFORMANCE 97............
APPENDIX III. WIRING DIAGRAMS 111...........
APPENDIX IV. MOTORMASTER SENSOR
LOCATIONS 149................................
UNIT START-UP CHECKLIST 151.................
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 perform the basic
maintenance functions of replacing filters. Trained service
personnel should perform all other operations.
When working on air-conditioning equipment, observe
precautions in the literature, tags and labels attached to
the unit, and other safety precautions that can 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 warnings 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
CAUTION. 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 indicates a hazardous
situation which, if not avoided, could result in death or
personal injury. CAUTION indicates a hazardous
situation which, if not avoided, could result in minor to
moderate injury or product and property damage.
NOTICE is used to address practices not related to

2
physical injury. NOTE is used to highlight suggestions
which will result in enhanced installation, reliability, or
operation.
IMPORTANT:Lockout/Tagout 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.
CUT HAZARD
Failure to follow this caution can result in personal
injury.
Sheet metal parts can have sharp edges or burrs. Use
care and wear appropriate protective clothing, safety
glasses and gloves when handling parts and servicing
air conditioning units.
CAUTION
!
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal
injury or death.
Before performing service or maintenance operations
on unit, LOCK--OUT/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. LOCK--OUT/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
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
!
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
Disconnect gas piping from unit when pressure testing
at pressure greater than 0.5 psig. Pressures greater
than 0.5 psig will cause gas valve damage resulting in
hazardous condition. If gas valve is subjected to
pressure greater than 0.5 psig, it must be replaced
before use. When pressure testing field-supplied gas
piping at pressures of 0.5 psig 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 personal
injury, death 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 personal
injury, death 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.
!WARNING
48TC

3
UNIT ARRANGEMENT AND ACCESS
General
Fig. 1 and Fig. 2 show the general unit arrangement and
access locations.
OUTDOOR-AIR OPENING
AND INDOOR COIL
ACCESS PANEL
COMPRESSOR
ACCESS PANEL
(04 - 07 only)
FILTER ACCESS
PANEL
C08449
Fig. 1 -- Typical Access Panel Locations
BLOWER
ACCESS
PANEL
FLUE
OPENING
CONTROL
BOX
COMPRESSOR
(08-12 only)
C08450
Fig. 2 -- Blower Access Panel Location
ROUTINE MAINTENANCE
The following items should be part of a routine
maintenance program and should to be checked every
month until a specific schedule for each can be identified
for this installation:
Quarterly Inspection (& 30 days after initial start)
SReplace return air filter
SClean outdoor hood inlet filters
SCheck belt tension
SCheck belt condition
SCheck pulley alignment
SCheck fan shaft bearing locking collar tightness
SCheck condenser coil for cleanliness
SCheck condensate drain
Seasonal Maintenance
The following items should be checked at the beginning
of each season (or more often if local conditions and
usage patterns dictate):
Air Conditioning
SEnsure condenser fan motor mounting bolts are tight
SEnsure compressor mounting bolts are tight
SCondenser fan blade positioning
SInspect control box for cleanliness and wiring condition
SEnsure wire terminal are tight
SCheck refrigerant charge level
SClean evaporator coil
SCheck evaporator blower motor amperage
Heating
SEnsure heat exchanger flue passageways are clean
SInspect gas burner condition
SCheck gas manifold pressure
SHeating temperature rise
Economizer or Outside Air Damper
SInspect condition of inlet filters
SCheck damper travel (economizer)
SCheck gear and dampers for debris and dirt
Air Filters and Screens
Each unit is equipped with return air filters. If the unit has
an economizer, it will also have an outside air screen. If a
manual outside air damper is added, an inlet air screen
will also be present.
All filters and screens will need to be periodically cleaned
or replaced.
Return Air Filters
Return air filters are a 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. 1.
48TC

4
PERSONAL INJURY HAZARD
Failure to follow this caution may result in premature
wear and damage to equipment.
Dirt and debris can collect on heat exchangers and
coils and can cause excessive current used resulting in
motor failure.
CAUTION
!
IMPORTANT: DO NOT OPERATE THE UNIT
WITHOUT THESE FILTERS!
Removing the Return Air Filters:
1. Grasp the bottom flange of the upper panel.
2. Lift up and swing the bottom out until the panel dis-
engages and pulls out.
3. Reach inside and remove the filters from the filter
rack.
4. Replace these filters, as required, with filters of
same size and media type.
Reinstalling the Access Panel:
1. Slide the top of the panel up under the unit’s top
panel.
2. Slide the bottom flange 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 screens for cleanliness. Remove
the screens when cleaning is required. Clean by washing
with hot low--pressure water and soft detergent. Replace
all screens before restarting the unit. Observe the flow
direction arrows on the side of each filter frame when
installing.
Economizer Inlet Air Screen
This air screen is retained by filter clips under the top
edge of the hood. See Fig. 3.
CLEANABLE
ALUMINUM
SCREEN
HOOD
FILTER
CLIP
OUTSIDE
AIR
BAROMETRIC
RELIEF
DIVIDER
17 1/4”
(438 mm)
C06027
Fig. 3 -- Inlet Air Screen Installation
Remove the screen by opening the filter clips. Re--install
the filter by placing the screen 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.
Remove the screen by loosening the screws in the top
retainer and sliding the retainer up until the filter can be
removed. Reinstall by placing the frame in its track,
rotating the retainer back down and tightening all screws.
C07156
Fig. 4 -- Screens Installed on Outdoor--Air Hood
(Sizes 7--1/2 to 15 Tons Shown)
48TC

5
MODEL NOMENCLATURE
Coil Options For Round Tube/Plate Fin Condenser Coil Models Only (outdoor-
indoor-hailguard)
A = Al/Cu - Al/Cu
B = Precoat Al/Cu - Al/Cu
C = E-coat Al/Cu - Al/Cu
D = E-coat Al/Cu - E-coat Al/Cu
E = Cu/Cu - Al/Cu
F = Cu/Cu - Cu/Cu
M = Al/Cu - Al/Cu – Louvered Hail Guards
N = Precoat Al/Cu - Al/Cu – Louvered Hail Guards
P = E-coat Al/Cu - Al/Cu – Louvered Hail Guards
Q = E-coat Al/Cu - E-coat Al/Cu – Louvered Hail Guards
R = Cu/Cu - Al/Cu – Louvered Hail Guards
S = Cu/Cu - Cu/Cu – Louvered Hail Guards
Coil Options For All Aluminum – Novation Condenser Coil Models Only
(outdoor-indoor-hailguard)
G = Al/Al – Al/Cu
H = Al/Al – Cu/Cu
J = Al/Al – E-coat Al/Cu
K = E-coat Al/Al – Al/Cu
L = E-coat Al/Al – E-coat Al/Cu
T = Al/Al – Al/Cu, Louvered Hail Guards
U = Al/Al – Cu/Cu, Louvered Hail Guards
V = Al/Al – E-coat Al/Cu, Louvered Hail Guards
W = E-coat Al/Al – Al/Cu, Louvered Hail Guards
X = E-coat Al/Al – E-coat Al/Cu, Louvered Hail Guards
4 8 T C D A 0 4 A 1 A 5 - 0 A 0 A 0
Unit Heat Type
48 – Gas Heat
Packaged
Rooftop
Series/Model
TC – Standard Efficiency
Heat Size
D – Low heat
E – Medium Heat
F – High Heat
L – Low NO
x
, Low Heat
M – Low NO
x
, Medium Heat
N – Low NO
x
, High Heat
S – Stainless Steel, Low Heat
R – Stainless Steel, Medium Heat
T – Stainless Steel, High Heat
Refrig. Systems Options
A - Standard One Stage Cooling Models
B – Standard One Stage Cooling Models
with Humidi-MiZer (04-07 models only)
D – Two Stage Cooling Models 08-16
E – Two Stage Cooling Models 08-16
with Al/Cu condenser Coils and
with Humidi-MiZer
Cooling Tons
04 - 3 ton 08 – 7.5 ton 16 – 15 Tons
05 - 4 ton 09 – 8.5 ton
06 - 5 ton 12 – 10 ton
07 - 6 ton 14 – 12.5 ton
Packaging and Seismic Compliant
0 = Standard
1 = LTL
3 = CA Seismic Compliant
4 = LTL and CA Seismic Compliant Label
Electrical Options
A = None
C = Non-Fused Disconnect
D = Thru-The-Base Connections
F = Non-Fused Disconnect and Thru-The-Base Connections
G = 2-Speed Indoor Fan (VFD) Controller
J = 2 Speed Fan Controller (VFD) and Non-Fused Disconnect
K = 2 Speed Fan Controller (VFD) and Thru-The Base Connections
M = 2 Speed Fan Controller (VFD) with Non-Fused Disconnect and
Thru-The Base Connections
Service Options
0 = None
1 = Unpowered Convenience Outlet
2 = Powered Convenience Outlet
3 = Hinged Panels
4 = Hinged Panels, Unpowered Convenience Outlet
5 = Hinged Panels, Powered Convenience Outlet
Intake / Exhaust Options
A = None
B = Temperature Economizer w/ Barometric Relief
F = Enthalpy Economizer w/ Barometric Relief
K = 2-Position Damper
U = Temp Ultra Low Leak Economizer w/Baro Relief
W = Enthalpy Ultra Low Leak Econo w/Baro Relief
Base unit controls
0 = Electromechanical Controls. Can be used with W7212 EconoMi$er IV
(factory or field installed)
1 = PremierLink Controller
2 = RTU Open Multi-Protocol Controller
6 = Electromechanical Controls. Can be used with W7220 EconoMi$er X
(factory or field installed)
Sensor Options
A = None
B = RA Smoke Detector
C = SA Smoke Detector
D = RA + SA Smoke Detector
E = CO2 Sensor
F = RA Smoke Detector and CO2 Sensor
G = SA Smoke Detector and CO2 Sensor
H = RA + SA Smoke Detector and CO2 Sensor
Indoor Fan Options
1 = Standard Static Option
2 = Medium Static Option
3 = High Static Option
C = High Static Option w/ High Effy Motor (Size 16 Only)
Design Revision
Factory Assigned
Voltage
1 = 575/3/60 5 = 208-230/3/60
3 = 208-230/1/60 6 = 460/3/60
123456789101112131415161718
Note: On single phase (-3 voltage code) models, the following
are not available as a factory installed option:
- Humidi-Mizer
- Coated Coils or Cu Fin Coils
- Louvered Hail Guards
- Economizer or 2 Position Damper
- Powered 115 Volt Convenience Outlet
Not all possible options can be displayed above.
C13211B
48TC

6
SUPPLY FAN (BLOWER) SECTION
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could cause personal
injury or death.
Before performing service or maintenance operations
on the fan system, shut off all unit power and
lock--out the unit disconnect switch. Place tag on
switch to notify others maintenance is being done.
Do not reach into the fan section with power still
applied to unit.
!WARNING
Supply Fan (Belt--Drive)
The supply fan system consists of a forward--curved
centrifugal blower wheel on a solid shaft with two
concentric type bearings, one on each side of the blower
housing. A fixed--pitch driven pulley is attached to the fan
shaft and an adjustable--pitch driver pulley is on the
motor. The pulleys are connected using a “V” type belt.
See Fig. 5.
BLOWER PULLEY
V-BELT
MOTOR
PULLEY
MOTOR
MOTOR MOUNTING
PLATE
MOUNTING
BOLTS (4)
C11504
Fig. 5 -- Belt Drive Motor Mounting
Belt
Check the belt condition and tension quarterly.
BROWNING BELT
TENSION CHECKER
STRAIGHTEDGE
1/2”
(1.3 cm)
BELT
DEFLECTION
C12093
Fig. 6 -- Checking Blower Motor Belt Tension
Changing Fan Speed:
1. Shut off unit power supply.
2. Loosen belt by loosening fan motor mounting nuts.
See Fig. 5.
3. Loosen movable pulley flange setscrew. See Fig. 7.
4. Screw movable flange toward fixed flange to in-
crease speed and away from fixed flange to decrease
speed. Increasing fan speed increases load on motor.
Do not exceed maximum speed specified.
5. Set movable flange at nearest keyway of pulley hub
and tighten setscrew to torque specifications.
Align fan and motor pulleys:
1. Loosen fan pulley setscrews.
2. Slide fan pulley along fan shaft. Make angular align-
ment by loosening motor from mounting.
3. Tighten fan pulley setscrews and motor mounting
bolts to torque specifications.
4. Recheck belt tension.
Inspect the belt for signs of cracking, fraying or glazing
along the inside surfaces. Check belt tension by using a
spring--force tool such as Browning’s “Belt Tension
Checker” (p/n: 1302546 or equivalent tool). Tension
should be 6--lbs at a ⅝--in. (1.6cm) deflection when
measured at the centerline of the belt span. This point is at
the center of the belt when measuring the distance
between the motor shaft and the blower shaft. See Fig. 6.
1. Place a straightedge along the belt between the two
pulleys.
2. Set the tension checker to the desired tension. Place
the large O--ring at that point.
3. Press the tension checker downward on the belt until
the large O--ring is at the bottom of the straightedge.
4. Adjust the belt tension as needed.
NOTE: Without the spring--tension tool, place a straight
edge across the belt surface at the pulleys, then deflect the
belt at mid--span using one finger to a ½--in. deflection.
Adjust belt tension by loosening the motor mounting plate
front bolts and rear bolt and sliding the plate toward the
fan (to reduce tension) or away from fan (to increase
tension). Ensure the blower shaft and the motor shaft are
parallel to each other (pulleys aligned). Tighten all bolts
securely when finished.
Replacing the belt:
1. Use a belt with same section type or similar size. Do
not substitute a “FHP” type belt. When installing the
new belt, do not use a tool (screwdriver or pry--bar)
to force the belt over the pulley flanges, this will
stress the belt and cause a reduction in belt life.
2. Loosen the motor mounting plate front bolts and rear
bolts.
3. Push the motor and its mounting plate towards the
blower housing as close as possible to reduce the
center distance between fan shaft and motor shaft.
4. Remove the belt by gently lifting the old belt over
one of the pulleys.
48TC

7
5. Install the new belt by gently sliding the belt over
both pulleys and then sliding the motor and plate
away from the fan housing until proper tension is
achieved.
6. Check the alignment of the pulleys, adjust if neces-
sary.
7. Tighten all bolts.
8. Check the tension after a few hours of runtime and
re--adjust as required.
Adjustable--Pitch Pulley on Motor
The motor pulley is an adjustable--pitch type that allows a
servicer to implement changes in the fan wheel speed to
match as--installed ductwork systems. The pulley consists
of a fixed flange side that faces the motor (secured to the
motor shaft) and a movable flange side that can be rotated
around the fixed flange side that increases or reduces the
pitch diameter of this driver pulley. See Fig. 7.
As the pitch diameter is changed by adjusting the position
of the movable flange, the centerline on this pulley shifts
laterally (along the motor shaft). This creates a
requirement for a realignment of the pulleys after any
adjustment of the movable flange. Also reset the belt
tension after each realignment.
Check the condition of the motor pulley for signs of wear.
Glazing of the belt contact surfaces and erosion on these
surfaces are signs of improper belt tension and/or belt
slippage. Pulley replacement can be necessary.
STRAIGHT EDGE
MUST BE PARALLEL
WITH BELT
SETSCREWS
MOTOR AND
FANSHAFTS
MUST BE
PARALLEL
FIXED FLANGE
MOVABLE
FLANGE
SINGLE - GROOVE
FAN PULLEY
MOTOR PULLEY
C07075
Fig. 7 -- Supply--Fan Pulley Adjustment
Bearings
This fan system uses bearings featuring concentric split
locking collars. The collars are tightened through a cap
screw bridging the split portion of the collar. The cap
screw has a Torx T25 socket head. To tighten the locking
collar: Hold the locking collar tightly against the inner
race of the bearing and torque the cap screw to 55--60
in--lb (6.2--6.8 Nm). See Fig. 8.
LOCKING COLLAR
T-25 TORX SOCKET
HEAD CAP SCREW
C11505
Fig. 8 -- Tightening Locking Collar
STAGED AIR VOLUME CONTROL (SAV) --
2 SPEED FAN WITH VARIABLE
FREQUENCY DRIVE (VFD)
Staged Air Volume (SAV) Indoor Fan Speed
System
The Staged Air Volume (SAV) system utilizes a fan speed
control board and Variable Frequency Drive (VFD) to
automatically adjust the indoor fan motor speed in
sequence with the unit’s ventilation, cooling and heating
operation. Per ASHRAE 90.1 2010standard section
6.4.3.10.b, during the first stage of cooling operation the
SAV system will adjust the fan motor to provide
two--thirds (2/3) of the design airflow rate for the unit.
When the call for the second stage of cooling is required,
the SAV system will allow the design airflow rate for the
unit established (100%). During the heating mode, the
SAV system will allow total design airflow rate (100%)
operation. During ventilation mode, the SAV system will
operate the fan motor at 2/3 speed.
Identifying Factory Option
This supplement only applies to units that meet the
criteria detailed in Table 1. If the unit does not meet that
criteria, discard this document.
Table 1 – Model--Size / VFD option Indicator
Model / Sizes Position in
Model Number
VFD FIOP
Indicator
48TC / 08---30 17 G, J
Unit Installation with SAV Option
Refer to the base unit installation instructions for standard
required operating and service clearances.
NOTICE: The remote VFD keypad is a field--installed
option. It is not included as part of the factory--installed
VFD option. See Figs. 9, 10 and 11 for locations of the
Variable Frequency Drive (VFD) as mounted on the
various 48TC models.
48TC

8
See “Variable Frequency Drive (VFD) Installation, Setup
and Troubleshooting Supplement” for wiring schematics
and performance charts and configuration.
VARIABLE
FREQUENCY
DRIVE (VFD)
C11528
Fig. 9 -- VFD Location for 48TC 08 -- 09 Units
VARIABLE
FREQUENCY
DRIVE (VFD)
C11529
Fig. 10 -- VFD Location for 48TC 12--14 Units
VARIABLE
FREQUENCY
DRIVE (VFD)
C11530
Fig. 11 -- VFD Location for 48TC 16 Unit
Additional Variable Frequency Drive (VFD)
Installation and Troubleshooting
Additional installation, wiring and troubleshooting
information for the Variable Frequency Drive can be
found in the following manual: “Variable Frequency
Drive (VFD) Installation, Setup and Troubleshooting
Supplement.” Have a copy of this manual on hand at
start--up.
SUPPLY FAN MOTOR
Replacing the Motor
When replacing the motor, also replace the external--tooth
lock washer (star washer) under the motor mounting base;
this is part of the motor grounding system. Ensure the
teeth on the lock washer are in contact with the motor’s
painted base. Tighten motor mounting bolts to 120 12
in--lbs.
BLOWER PULLEY
V-BELT
MOTOR
PULLEY
MOTOR
MOTOR MOUNTING
PLATE
MOUNTING
BOLTS (4)
C11504
Fig. 12 -- Replacing Belt Driven Motor
Use the following steps to replace the belt--driven motor.
1. Turn off all electrical power to the unit. Use
approved lockout/tagout procedures on all electrical
power sources.
2. Remove cover on motor connection box.
3. Disconnect all electrical leads to the motor.
4. Loosen four mounting plate bolts.
5. Move motor assembly toward blower assembly.
6. Remove V--belt from blower pulley and motor
pulley.
7. Remove four bolts, four flat washers, four lock
washers and four nuts attaching the motor mounting
plate to the unit. Discard all lock washers.
8. Remove motor and motor mounting plate from unit.
9. Remove four bolts, four flat washers, four lock
washers and one external--tooth lock washer
attaching motor to the motor mounting plate. Discard
all lock washers and external--tooth lock washer.
10. Lift motor from motor mounting plate and set aside.
11. Slide motor mounting band from old motor.
12. Slide motor mounting band onto new motor and set
motor onto the motor mounting plate.
48TC

9
13. Inspect variable pitch pulley on old motor for cracks
and wear.
14. Remove variable pitch pulley from old motor and
attach it to the new motor. Secure the pulley to the
motor by tightening the setscrew to the motor shaft.
15. Insert four bolts and flat washers through holes in
the motor mounting band into holes on the motor
mounting plate.
16. On one bolt, place a new external--tooth lock washer
between the motor and motor mounting plate.
17. Ensure the teeth of the external--tooth lock washer
make contact with the painted base of the motor.
This washer is essential for properly grounding
motor.
18. Install four new lock washers and four nuts on the
bolts on the bottom of the motor mounting plate.
19. Do Not tighten the mounting bolts at this time.
20. Install four bolts, four flat washers, four new lock
washers and four nuts attaching the motor assembly
to the unit.
21. Do Not tighten the mounting bolts at this time.
22. Install motor drive V--belt to motor pulley and
blower wheel pulley. See CAUTION below.
23. Align the motor pulley and blower wheel pulley
using a straight edge. See Fig. 7.
24. Adjust the V--belt tension using adjustment tool. See
Fig. 13.
BROWNING BELT
TENSION CHECKER
STRAIGHTEDGE
1/2”
(1.3 cm)
BELT
DEFLECTION
C12093
Fig. 13 -- Adjusting V--belt Tension
25. Tighten four bolts securing motor to motor mounting
plate. Torque four bolts to 120 12 in--lbs (14 1.4
Nm).
26. Tighten four bolts securing motor mounting plate to
unit. Torque four bolts to 120 12 in--lbs (14 1.4
Nm).
27. Remove cover on new motor connection box.
28. Re--connect all electrical leads to the motor and
replace the connection box cover.
29. Re--connect all electrical power to the unit. Remove
lockout tags on all electrical power sources.
30. Start unit and allow to run for a designated period.
31. Shut off unit and make any necessary adjustments to
the V--belt tension or the motor and blower wheel
pulley alignment.
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution can result in premature
wear and damage to equipment.
Do not use a screwdriver or a pry bar to place the new
V--belt in the pulley groove. This can cause stress on
the V--belt and the pulley resulting in premature wear
on the V--belt and damage to the pulley.
CAUTION
!
Changing Fan Wheel Speed by Changing Pulleys
The horsepower rating of the belt is primarily dictated by
the pitch diameter of the smaller pulley in the drive
system (typically the motor pulley in these units). Do not
install a replacement motor pulley with a smaller pitch
diameter than provided on the original factory pulley.
Change fan wheel speed by changing the fixed fan pulley
(larger pitch diameter to reduce wheel speed, smaller
pitch diameter to increase wheel speed) or select a new
system with both pulleys and matching belt(s).
Before changing pulleys to increase fan wheel speed,
check the fan performance at the target speed and airflow
rate to determine new motor loading (bhp). Use the fan
performance tables or use the Packaged Rooftop Builder
software program. Confirm that the motor in this unit is
capable of operating at the new operating condition. Fan
shaft loading increases dramatically as wheel speed is
increased.
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution can result in equipment
damage.
Drive packages cannot be changed in the field. For
example: a standard drive cannot be changed to a high
static drive. This type of change will alter the unit’s
certification and could require heavier wiring to
support the higher amperage draw of the drive
package.
CAUTION
!
To reduce vibration, replace the motor’s adjustable pitch
pulley with a fixed pitch pulley (after the final airflow
balance adjustment). This will reduce the amount of
vibration generated by the motor/belt--drive system.
To determine variable pitch pulley diameter perform the
following calculation:
1. Determine full open and full closed pulley diameter.
2. Subtract the full open diameter from the full closed
diameter.
3. Divide that number by the number of pulley turns
open from full closed
This number is the change in pitch datum per turn
open.
48TC

10
EXAMPLE
--Pulley dimensions 2.9 to 3.9 (full close to full open)
-- 3 . 9 -- 2 . 9 = 1
--1 divided by 5 (turns from full close to full open)
--0.2 change in pulley diameter per turn open
--2.9 + 0.2 = 3.1--in pulley diameter when pulley closed
one turn from full open
COOLING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal
injury, death and/or equipment damage.
This system uses PuronRrefrigerant which has
higher pressures than R--22 and other refrigerants. No
other refrigerant can 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.
!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.
!WARNING
Condenser Coils Size D08--D14
All 48TC units are available with Round Tube/Plate Fin
(RTPF) coil construction. 48TC units with size
designations D08, D12 and D14 are also available with
optional all--aluminum Novation coil construction. Check
position 11 on the unit’s infomative data plate for coil
construction code, then refer to Model Nomenclature on
page 5 to confirm this unit’s coil construction type.
Novation (MCHX) Condenser Coil
The condenser coil uses new NOVATIONHeat
Exchanger Technology or Microchannel Heat Exchanger.
Coil (MCHX). This is an all--aluminum construction with
louvered fins over single--depth crosstubes. The crosstubes
have multiple small passages (microchannels) through
which the refrigerant passes from header to header on
each end. Tubes and fins are made of aluminum.
Connection tube joints are made of copper. The coil can
be one--row or two--row. Two--row coils are spaced apart
to assist in cleaning. See Fig. 14.
Routine Cleaning of NOVATION Condenser Coil
Surfaces
DO NOT clean the NOVATION condenser coil with
chemicals. ONLY water is approved as the cleaning
solution. Only clean potable water is authorized for
cleaning NOVATION condensers. Carefully remove any
foreign objects or debris attached to the coil face or
trapped within the mounting frame and brackets. Using a
high pressure water sprayer, purge any soap or industrial
cleaners from hose and/or dilution tank prior to wetting
the coil.
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 operating
refrigerant compressors. Pressurized
mixtures of air or gases containing
oxygen can lead to an explosion.
!WARNING
TUBES
FINS
MANIFOLD
MICROCHANNELS
C07273B
Fig. 14 -- Novation (Microchannel) Coil
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution can result in equipment
damage.
DO NOT use Totalineenvironmentally sound coil
cleaner on the aluminum NOVATION condenser.
Damage to the coil can occur. Only clean potable
water is authorized for cleaning.
CAUTION
!
48TC