Carrier 25hba User manual

1
Installation Instructions
25HBA
BASETSERIES PURONRREFRIGERANT HEAT PUMPS
SIZES 018 TO 060
1 1/2 TO 5 NOMINAL TONS
A05341
Fig. 1 -- 25HBA Standard Grille Unit
NOTE:Read the entire instruction manual before starting the
installation.
TABLE OF CONTENTS
Page
Safety Considerations 2...............................
Installation Recommendations 2........................
Installation 3--12....................................
Step 1 -- Check Equipment & Jobsite 3...............
Step 2 -- Install on Solid Pad 3......................
Step 3 -- Clearance Requirements 3..................
Step 4 -- Operating Ambient 3......................
Step 5 -- Elevate Unit 3...........................
Step 6 -- Install TXV 3 -- 4.........................
Step 7 -- Check Defrost Thermostat 4.................
Step 8 -- Make Piping Connections 5 -- 8..............
Step 9 -- Make Electrical Connections 8 -- 9............
Step 10 -- Compressor Crankcase Heater 9.............
Step 11 -- Install Electrical Accessories 9..............
Step 12 -- Start--Up 9 -- 11..........................
Step 13 -- Check Charge 12.........................
Step 14 -- Final Checks 12..........................
Care and Maintenance 12.............................

2
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service,
maintenance, or use can cause explosion, fire, electrical shock, or
other conditions which may cause death, personal injury, or
property damage. Consult a qualified installer, service agency, or
your distributor or branch for information or assistance. The
qualified installer or agency must use factory--authorized kits or
accessories when modifying this product. Refer to the individual
instructions packaged with the kits or accessories when installing.
Follow all safety codes. Wear safety glasses, protective clothing,
and work gloves. Use quenching cloth for brazing operations.
Have fire extinguisher available. Read these instructions
thoroughly and follow all warnings or cautions included in
literature and attached to the unit. Consult local building codes
and National Electrical Code (NEC) for special requirements.
Recognize safety information. This is the safety--alert symbol
!
!
.
When you see this symbol on the unit and in instructions or
manuals, be alert to the potential for personal injury.
Understand these signal words; DANGER, WARNING, and
CAUTION. These words are used with the safety--alert symbol.
DANGER identifies the most serious hazards which will result in
severe personal injury or death.
WARNING signifies hazards which could result in personal
injury or death. CAUTION is used to identify unsafe practices
which may result in minor personal injury or product and
property damage. NOTE is used to highlight suggestions which
will result in enhanced installation, reliability, or operation.
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing, modifying, or servicing system, main
electrical disconnect switch must be in the OFF position.
There may be more than 1 disconnect switch. Lock out
and tag switch with a suitable warning label.
INSTALLATION RECOMMENDATIONS
NOTE: In some cases noise in the living area has been traced to
gas pulsations from improper installation of equipment.
1. Locate unit away from windows, patios, decks, etc. where unit
operation sound may disturb customer.
2. Ensure that vapor and liquid tube diameters are appropriate for
unit capacity.
3. Run refrigerant tubes as directly as possible by avoiding
unnecessary turns and bends.
4. Leave some slack between structure and unit to absorb
vibration.
5. When passing refrigerant tubes through the wall, seal opening
with RTV or other pliable silicon--based caulk. (See Fig. 2.)
6. Avoid direct tubing contact with water pipes, duct work, floor
joists, wall studs, floors, and walls.
7. Do not suspend refrigerant tubing from joists and studs with a
rigid wire or strap which comes in direct contact with tubing. (See
Fig. 2.)
8. Ensure that tubing insulation is pliable and completely
surrounds vapor tube.
9. When necessary, use hanger straps which are 1 in. wide and
conform to shape of tubing insulation. (See Fig. 2.)
10. Isolate hanger straps from insulation by using metal sleeves
bent to conform to shape of insulation.
INSULATION
VAPOR TUBE
LIQUID TUBE
OUTDOOR WALL INDOOR WALL
LIQUID TUBE
VAPOR TUBE
INSULATION
CAULK
Avoid contact between tubing and structureNOTE:
THROUGH THE WALL
HANGER STRAP
(AROUND VAPOR
TUBE ONLY)
JOIST
1″MIN.
SUSPENSION
A94028
Fig. 2 -- Connecting Tubing Installation
When outdoor unit is connected to factory--approved indoor unit,
outdoor unit contains system refrigerant charge for operation with
ARI rated indoor unit when connected by 15 ft of field--supplied
or factory accessory tubing. For proper unit operation, check
refrigerant charge using charging information located on control
box cover and/or in the Check Charge section of this instruction.
IMPORTANT:Maximum liquid--line size is 3/8--in. OD for all
residential applications including line line.
IMPORTANT: Always install the factory--supplied liquid--line
filter drier. If replacing the filter drier, refer to Product Data Digest
for appropriate part number. Obtain replacement filter driers from
your distributor or branch.
25HBA

3
INSTALLATION
Step 1.—Check Equipment and Job Site
UNPACK UNIT
Move to final location. Remove carton taking care not to damage
unit.
INSPECT EQUIPMENT
File claim with shipping company prior to installation if shipment
is damaged or incomplete. Locate unit rating plate on unit corner
panel. It contains information needed to properly install unit.
Check rating plate to be sure unit matches job specifications.
Step 2.—Install on a Solid, Level Mounting Pad
If conditions or local codes require the unit be attached to pad, tie
down bolts should be used and fastened through knockouts
provided in unit base pan. Refer to unit mounting pattern in Fig.
3 to determine base pan size and knockout hole location.
For hurricane tie downs, contact distributor for details and PE
Certification (Professional Engineer), if required.
On rooftop applications, mount on level platform or frame. Place
unit above a load--bearing wall and isolate unit and tubing set
from structure. Arrange supporting members to adequately
support unit and minimize transmission of vibration to building.
Consult local codes governing rooftop applications.
Roof mounted units exposed to winds above 5 mph may require
wind baffles. Consult the Service Manual -- Residential Split
System Air Conditioners and Heat Pumps for wind baffle
construction.
NOTE: Unit must be level to within ±2°(±3/8 in./ft) per
compressor manufacturer specifications.
Step 3.—Clearance Requirements
When installing, allow sufficient space for airflow clearance,
wiring, refrigerant piping, and service. Allow 30--in. clearance to
service end of unit and 48 in. above unit. For proper airflow, a
6--in. clearance on 1 side of unit and 12 in. on all remaining sides
must be maintained. Maintain a distance of 24 in. between units.
Position so water, snow, or ice from roof or eaves cannot fall
directly on unit.
3/8 ---in. Dia. Tiedown
Knockouts in Basepan
(2) Places
View From Top
UNIT BASE PAN
DIMENSIONS
TIEDOWN KNOCKOUT LOCATIONS
A B C
26 X 26 9–1/8 4–7/16 21–1/4
31–1/2 X 31–1/2 9–1/8 6–9/16 24–11/16
35 X 35 9–1/8 6–9/16 28–7/16
A05177
Fig. 3 -- Tiedown Knockout Requirements
On rooftop applications, locate unit at least 6 in. above roof
surface.
Step 4.—Operating Ambient
The minimum outdoor operating ambient in cooling mode is
55°F, and the maximum outdoor operating ambient in cooling
mode is 125°F. The maximum outdoor operating ambient in
heating mode is 66 °F.
Step 5.—Elevate Unit
CAUTION
!
UNIT OPERATION HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
To avoid improper performance and possible
equipment failure, unit must be kept free of an
accumulation of water and/or ice in the basepan.
Elevate unit per local climate and code requirements to provide
clearance above estimated snowfall level and ensure adequate
drainage of unit. If using accessory support feet, use installation
instructions from kit for installation.
CAUTION
!
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
To prevent damage to the unit, ensure that it is located
with the supports such that the unit is stable in all
circumstances including adverse conditions.
Step 6.—Install TXV
NOTE: Applies to non--TXV indoor units only. If installing a
rated and approved indoor coil without a factory installed
PuronRTXV, remove and replace the fixed orifice or R--22
TXV expansion device with a hard shutoff Puron TXV.
The thermostatic expansion valve is specifically designed to
operate with Puron Refrigerant. Do not use an R--22 TXV. An
existing R--22 TXV must be replaced with a factory approved
TXV specifically designed for Puron Refrigerant. Refer to
Product Data Digest for the appropriate TXV kit number.
CAUTION
!
UNIT OPERATION HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
To avoid improper performanceand possibleequipment
failure, all indoor coil units must be installed with a hard
shutoff Puron TXV metering device.
IMPORTANT: If not factory installed, the TXV should be
mounted as close to the indoor coil as possible and in a vertical,
upright position. Avoid mounting the inlet tube vertically down.
25HBA

4
Valve is more susceptible to malfunction due to debris if inlet tube
is facing down. A factory--approved filter drier must be installed in
the liquid line.
INSTALLING TXV IN PLACE OF PISTON
1. Pump system down to 2 psig and recover refrigerant.
2. Remove hex nut from piston body. Use backup wrench on fan
coils.
3. Remove and discard factory--installed piston. Be sure TeflonR
seal is in place.
4. Reinstall hex nut. Finger tighten nut plus 1/2 turn.
NOTE:If the piston is not removed from the body, TXV will not
function properly.
CAUTION
!
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
To prevent damage to the unit, use a brazing shield and
wrap TXV with wet cloth or use heat sink material.
5. Install TXV on indoor coil liquid line. Sweat swivel adapter to
inlet of indoor coil and attach to TXV outlet. Use backup wrench
to avoid damage to tubing or valve. Sweat inlet of TXV, marked
“IN” to liquid line. Avoid excessive heat which could damage
valve.
6. Install vapor elbow with equalizer adapter to suction tube
of line set and suction connection to indoor coil. Adapter has a
1/4--in. male connector for attaching equalizer tube.
7. Connect equalizer tube of TXV to 1/4--in. equalizer fitting on
vapor line adapter.
8. Attach TXV bulb to horizontal section of suction line using
clamps provided. Insulate bulb with field--supplied insulation
tape. See Fig. 4 for correct positioning of sensing bulb.
9. Proceed with remainder of unit installation.
2 O'CLOCK
10 O'CLOCK
SENSING BULB
STRAP
SUCTION TUBE
8 O'CLOCK 4 O'CLOCK
7
⁄
8
IN. OD & SMALLER LARGER THAN
7
⁄
8
IN. OD
A81032
Fig. 4 -- Position of Sensing Bulb
REPLACING TXV ON R--22 INDOOR COIL
1. Pump system down to 2 psig and recover refrigerant.
2. Remove coil access panel and fitting panel from front of
cabinet.
3. Remove TXV support clamp using a 5/16--in. nut driver. Save
the clamp.
4. Remove R--22 TXV using a backup wrench on flare
connections to prevent damage to tubing.
5. Using wire cutters, cut equalizer tube off flush with vapor tube
inside cabinet.
6. Remove bulb from vapor tube inside cabinet.
7. Braze equalizer stub--tube closed. Use protective barrier as
necessary to prevent damage to drain pan.
IMPORTANT: Route the equalizer tube of Puron TXV through
suction line connection opening in fitting panel prior to replacing
fitting panel around tubing.
8. Install TXV with 3/8--in. copper tubing through small hole in
service panel. Use wrench and backup wrench, to avoid damage
to tubing or valve, to attach TXV to distributor.
9. Reinstall TXV support clamp (removed in item 3).
10. Attach TXV bulb to vapor tube inside cabinet, in same
location as original was when removed, using supplied bulb
clamps (nylon or copper). See Fig. 4 for correct positioning of
sensing bulb.
11. Route equalizer tube through suction connection opening
(large hole) in fitting panel and install fitting panel in place.
12. Sweat inlet of TXV, marked IN to liquid line. Avoid
excessive heat which could damage valve.
13. Install vapor elbow with equalizer adapter to vapor line of
line set and vapor connection to indoor coil. Adapter has a
1/4--in. male connector for attaching equalizer tube.
14. Connect equalizer tube of TXV to 1/4--in. equalizer fitting on
vapor line adapter. Use backup wrench to prevent damage to
equalizer fitting.
15. Proceed with remainder of unit installation.
A05226
Fig. 5 -- Liquid Service Valve with Sweat Adapter Tube
25HBR25HBA25HBA

5
Step 7.—Check Defrost Thermostat
Check defrost thermostat to ensure it is properly located and
securely attached. There is a liquid header with a brass distributor
and feeder tube going into outdoor coil. At the end of the one of
the feeder tubes, there is a 3/8 in. O.D. stub tube approximately 2
in. long. (See Fig. 6.) The defrost thermostat should be located on
stub tube. Note that there is only one stub tube used with liquid
header, and on most units it is the bottom circuit.
FEEDER TUBE
DEFROST
THERMOSTAT
STUB TUBE
A97517
Fig. 6 -- Defrost Thermostat Location
Step 8.—Make Piping Connections
!
WARNING
PERSONAL INJURY AND UNIT DAMAGE
HAZARD
Failure to follow this warning could result in personal
injury or death.
Relieve pressure and recover all refrigerant before
system repair or final unit disposal to avoid personal
injury or death. Use all service ports and open all
flow--control devices, including solenoid valves.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
or improper operation.
If ANY refrigerant tubing is buried, provide a 6--in. vertical
rise at service valve. Refrigerant tubing lengths up to 36--in.
may be buried without further special consideration. Do not
bury lines longer than 36 in.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
To prevent damage to unit or service valves, observe the
following:
SUse a brazing shield
SWrap service valves with wet cloth or use a heat sink
material.
Outdoor units may be connected to indoor section using
accessory tubing package or field--supplied refrigerant grade
tubing of correct size and condition. For tubing requirements
beyond 80 ft., substantial capacity and performance losses can
occur. Following the recommendations in the Long Line
Guideline for Split--System Air Conditioners and Heat Pumps
will reduce these losses. Refer to Table 1 for accessory
requirements. Refer to Table 2 for field tubing diameters.
If refrigerant tubes or indoor coil are exposed to atmosphere, they
must be evacuated to 500 microns to eliminate contamination and
moisture in the system.
25HBA

6
Table 1—Accessory Usage
Accessory
REQUIRED FOR LOW---AMBI-
ENT APPLICATIONS
(Below 55 °F)
REQUIRED FOR LONG LINE
APPLICATIONS* (Over 80 Ft)
REQUIRED FOR SEA
COAST APPLICATIONS
(Within 2 miles)
Crankcase Heater Yes Yes No
Evaporator Freeze Thermostat Yes
No
No
Winter Start Control Yes
No
No
Accumulator No
No
No
Compressor Start Assist Capacitor
and Relay Yes
Yes
No
Motor Master®Control Yes{
No
No
Support Feet Recommended
No
Recommended
Liquid Line Solenoid Valve Yes See Long --- Line Application
Guideline No
Ball Bearing Fan Motor Yes
}No
No
* For Tubing Set lengths between 80 and 200 ft. horizontal or 20 ft. vertical differential (250 ft Total Equivalent Length), refer to the Long Line Guidelines for
Air Conditioners and Heat Pumps using R---22.
{Required for low---ambient controller (full modulation feature) and Motor Mastercontrol only.
Table 2—Refrigerant Connections and Recommended Liquid and Vapor Tube Diameters (In.)
UNIT SIZE LIQUID VAPOR (up to 80 ft)
Connection Diameter Tube Diameter Connection Diameter Rated Tube Diameter
018, 024 3/8 3/8 5/8 5/8
030, 036 3/8 3/8 3/4 3/4
042, 048 3/8 3/8 7/8 7/8
060 3/8 3/8 7/8 1--1/8
Notes:
1. Tube diameters are for total equivalent lengths up to 80 ft..
2. Do not apply capillary tube or fixed orifice indoor coils to these units.
* For Tubing Set lengths between 80 and 200 ft. horizontal or 20 ft. vertical differential (250 ft.Total Equivalent Length), refer to the Longline
G u i d e l i n e --- A i r C o n d i t i o n e r s a n d H e a t P u m p s u s i n g R --- 2 2
25HBA

7
OUTDOOR UNIT CONNECTED TO FACTORY APPROVED
INDOOR UNIT
These outdoor units are carefully evaluated and listed with
specific indoor coils for proper system performance.
IMPORTANT: Do not apply indoor coils which are not factory
approved to these units.
INSTALL ADAPTER TUBE
1. Remove plastic retainer holding outdoor piston in liquid
service valve.
2. Check outdoor piston size with matching number listed on unit
rating plate.
3. Locate plastic bag taped to unit containing adapter tube.
4. Remove Teflonwasher from bag and install on open end of
liquid service valve. (See Fig. 5.)
5. Remove adapter tube from bag and connect threaded nut to
liquid service valve. Tighten nut finger--tight and then with
wrence an additional 1/2 turn (15 ft--lb). DO NOT OVER
TIGHTEN!
REFRIGERANT TUBING AND SWEAT CONNECTIONS
Connect vapor tube to fitting on outdoor unit vapor service
valves (see Table 2). Connect liquid tubing to adapter tube on
liquid
service valve. Use refrigerant grade tubing.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
To avoid valve damage while brazing, service valves
must be wrapped in a heat--sinking material such as a wet
cloth.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
or improper operation.
To avoid performance loss and compressor failure, installation
of filter drier in liquid line is required.
INSTALL LIQUID LINE FILTER DRIER INDOOR
Refer to Fig. 7 and install filter drier as follows:
1. Braze 5 in. liquid tube to the indoor coil.
2. Wrap filter drier with damp cloth.
3. Braze filter drier to 5 in. long liquid tube from step 1.
4. Connect and braze liquid refrigerant tube to the filter drier.
A05227
Fig.7--LiquidLineFilterDrier
LEAK TESTING
Leak test all joints indoors, outdoors, and refrigerant tubing.
EVACUATE REFRIGERANT TUBING AND INDOOR COIL
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
To avoid compressor damage never use the system
compressor as a vacuum pump.
Refrigerant tubes and indoor coil should be evacuated using the
recommended the recommended deep vacuum method of 500
microns. The alternate triple evacuation method may be used if
the procedure outlined below is followed.
IMPORTANT: Always break a vacuum with dry nitrogen.
25HBA

8
DEEP VACUUM METHOD
The deep vacuum method requires a vacuum pump capable of
pulling a vacuum of 500 microns and a vacuum gage capable of
accurately measuring this vacuum depth. The deep vacuum
method is the most positive way of assuring a system is free of air
and liquid water. See Fig. 8.
500
MINUTES
01234567
1000
1500
LEAK IN
SYSTEM
VACUUM TIGH
T
TOO WET
TIGHT
DRY SYSTEM
2000
MICRONS
2500
3000
3500
4000
4500
5000
A95424
Fig. 8 -- Deep Vacuum Graph
CHECK FOR TIGHT, DRY SYSTEM 
(IF IT HOLDS DEEP VACUUM)
EVACUATE
BREAK VACUUM WITH DRY NITROGEN
WAIT
EVACUATE
CHARGE SYSTEM
BREAK VACUUM WITH DRY NITROGEN
EVACUATE
WAIT
A95425
Fig. 9 -- Triple Evacuation Method
TRIPLE EVACUATION METHOD
The triple evacuation method should only be used when vacuum
pump is only capable of pumping down to 28 in. of mercury
vacuum, and system does not contain any liquid water. Refer to
Fig. 9 and proceed as follows:
1. Pump system down to 28 in. of mercury and allow pump to
continue operating for an additional 15 minutes.
2. Close service valves and shut off vacuum pump.
3. Connect a nitrogen cylinder and regulator to system and open
until system pressure is 2 psig.
4. Close service valve and allow system to stand for 1 hour.
During this time, dry nitrogen will be able to diffuse throughout
the system absorbing moisture.
5. Repeat this procedure as indicated by Fig. 9. System will then
be free of any contaminants and water vapor.
FINAL TUBING CHECK
IMPORTANT: Check to be certain factory tubing on both indoor
and outdoor unit has not shifted during shipment. Ensure tubes are
not rubbing against each other or any sheet metal. Pay close
attention to feeder tubes, makings sure wire ties on feeder tubes are
secure and tight.
Step 9.—Make Electrical Connections
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
To avoid personal injury or death, do not supply power to
unit with compressor terminal box cover removed.
Be sure field wiring complies with local and national fire, safety,
and electrical codes, and voltage to system is within limits shown
on unit rating plate. Contact local power company for correction
of improper voltage. See unit rating plate for recommended
circuit protection device.
NOTE: Operation of unit on improper line voltage constitutes
abuse and could affect unit reliability. See unit rating plate. Do
not install system where voltage may fluctuate above or below
permissible limits.
NOTE: Use copper wire only between disconnect switch and
unit.
NOTE: Install branch circuit disconnect of adequate size per
NEC to handle unit starting current. Locate disconnect within
sight from and readily accessible from unit, per Section 440--14
of NEC.
ROUTE GROUND AND POWER WIRES
Remove access panel to gain access to unit wiring. Extend wires
from disconnect through power wiring hole provided and into
unit control box.
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
The unit cabinet must have an uninterrupted or unbroken
ground to minimize personal injury if an electrical fault
should occur. The ground may consist of electrical wire or
metal conduit when installed in accordance with existing
electrical codes. Failure to follow this warning can result in an
electric shock, fire, or death.
25HBA

9
CONNECT GROUND AND POWER WIRES
Connect ground wire to ground connection in control box for
safety. Connect power wiring to contactor as shown in Fig. 10.
DISCONNECT
PER N. E. C. AND/OR
LOCAL CODES
CONTACTOR
GROUND
LUG
FIELD GROUND
WIRING
FIELD POWER
WIRING
A91056
Fig. 10 -- Line Connections
CONNECT CONTROL WIRING
Route 24v control wires through control wiring grommet and
connect leads to control wiring. See Thermostat Installation
Instructions for wiring specific unit combinations. (See Fig. 11.)
Use No. 18 AWG color--coded, insulated (35°C minimum) wire.
If thermostat is located more than 100 ft from unit, as measured
along the control voltage wires, use No. 16 AWG color--coded
wire to avoid excessive voltage drop.
All wiring must be NEC Class 1 and must be separated from
incoming power leads.
Use furnace transformer, fan coil transformer, or accessory
transformer for control power, 24v/40va minimum.
NOTE: Use of available 24v accessories may exceed the
minimum 40va power requirement. Determine total transformer
loading and increase the transformer capacity or split the load
with an accessory transformer as required.
FINAL WIRING CHECK
IMPORTANT: Check factory wiring and field wire connections
to ensure terminations are secured properly. Check wire routing to
ensure wires are not in contact with tubing, sheet metal, etc.
Step 10.—Compressor Crankcase Heater
When equipped with a crankcase heater, furnish power to heater a
minimum of 24 hr before starting unit. To furnish power to heater
only, set thermostat to OFF and close electrical disconnect to
outdoor unit.
A crankcase heater is required if refrigerant tubing is longer than
80 ft. Refer to the Long Line Guideline--Residential Split--System
Air Conditioners and Heat Pumps.
Step 11.—Install Electrical Accessories
Refer to the individual installation instructions packaged with kits
or accessories when installing.
Step 12.—Start--Up
CAUTION
!
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this caution may result in minor personal injury,
equipment damage or improper operation.
To prevent compressor damage or personal injury,
observe the following:
SDo not overcharge system with refrigerant.
SDo not operate unit in a vacuum or at negative pressure.
SDo not disable low pressure switch in scroll compressor
applications.
SDome temperatures may be hot.
CAUTION
!
PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal
injury.
To prevent personal injury wear safety glasses, protective
clothing, and gloves when handling refrigerant and observethe
following:
SBack seating service valves are not equipped with Schrader
valves. Fully back seat (counter clockwise) valve stem
before removing gage port cap.
SFront seating service valves are equipped with Schrader
valves.
CAUTION
!
ENVIRONMENTAL HAZARD
Failure to follow this caution may result in environmental
damage.
Federal regulations require that you do not vent refrigerant to the
atmosphere. Recover during system repair or final unit disposal.
25HBA

10
FOLLOW THESE STEPS TO PROPERLY START UP
SYSTEM:
1. After system is evacuated, fully open liquid and vapor service
valves.
2. Unit is shipped with valve stem(s) closed and caps installed.
Replace stem caps after system is opened to refrigerant flow (back
seated). Replace caps finger--tight and tighten with wrench an
additional 1/12 turn.
3. Close electrical disconnects to energize system.
4. Set room thermostat at desired temperature. Be sure set point
is below indoor ambient temperature.
5. Set room thermostat to HEAT or COOL and fan control to ON
or AUTO mode, as desired. Operate unit for 15 minutes. Check
system refrigerant charge.
CAUTION
!
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this caution may result in minor personal injury,
equipment damage or improper operation.
To prevent compressor damage or personal injury,
observe the following:
SDo not overcharge system with refrigerant.
SDo not operate unit in a vacuum or at negative pressure.
SDo not disable low pressure switch in scroll compressor
applications.
SDome temperatures may be hot.
SIn 3 phase applications, incorrect phasing will cause reverse
rotation, resulting in elevated noise levels, equalized
pressures and reduced current draw. Correct by reversing
power connection L1 and L2 on contactor.
24 VAC HOT R
C
W2
Y
G
R
C
RVS COOLING
C
W2
HP THERMOSTAT
TYPICAL
FAN COIL
HEAT
PUMP
G
O
E
W2
E
W3
R
Y
24 VAC COM
HEAT STAGE 2
COOL/HEAT
STAGE 1
INDOOR FAN
EMERGENCY
HEAT
O
*
*
*
IF AVAILABLE
*
LEGEND
24-V FACTORY WIRING
24-V FIELD WIRING
FIELD SPLICE CONNECTION
OUTDOOR THERMOSTAT
EMERGENCY HEAT RELAY
SUPPLEMENTAL HEAT RELAY
SHR
EHR
ODT
A02325 / A97413
Fig. 11 -- Generic Wiring Diagrams
(See Thermostat Installation Instructions for specific unit
combinations)
25HBA

11
SEQUENCE OF OPERATION
Turn on power to indoor and outdoor units. Transformer is
energized with power supplied.
COOLING
On a call for cooling, thermostat makes circuits R--O and R--Y,
and R--G. Circuit R--O energizes reversing valve, switching it to
cooling position. Circuit R--Y energizes contactor, starting
outdoor fan motor and compressor circuit. R--G energizes indoor
unit blower relay, starting indoor blower motor on high speed.
When thermostat is satisfied, its contacts open, de--energizing
contactor and blower relay. Compressor and motors should stop.
NOTE: If indoor unit is equipped with a time--delay relay
circuit, the indoor blower will run an additional 90 seconds to
increase system efficiency.
HEATING
On a call for heating, thermostat makes circuits R--Y and R--G.
Circuit R--Y energizes contactor, starting outdoor fan motor and
compressor. Circuit R--G energizes indoor blower relay, starting
blower motor on high speed.
Should temperature continue to fall, R--W2 is made through
second--stage room thermostat. Circuit R--W2 energizes a relay,
bringing on first bank of supplemental electric heat and providing
electrical potential to second heater relay (if used). If outdoor
temperature falls below setting of outdoor thermostat (field
installed option), contacts close to complete circuit and bring on
second bank of supplemental electric heat.
When thermostat is satisfied, its contacts open, de--energizing
contactor and relay. All heaters and motors should stop after all
fan off delays.
OUTDOOR FAN
RELAY
Y OUTPUT TO PRESSURE
SWITCHES AND CONTACTOR
THERMOSTAT INPUTS
T1 - ENABLES DEFROST
TIMER. MUST BE
ENERGIZED FOR
DEFROST TIMER
TO START
C - COMMON
O - REVERSING VALVE
SPEEDUP
HK32EA001
DEFROST THERMOSTAT
MUST BE CLOSED BEFORE
DEFROST TIMER BEGINS
A05332
Fig. 12 -- Defrost Control
DEFROST
The defrost control is a time/temperature control which includes a
field selectable time period of 30, 60, or 90 minutes, factory set
to 90 minutes. This is the time the defrost thermostat must be
closed before the defrost cycle begins.
The electronic defrost timer sequence is enabled when the T1
input on the board is energized. The timer starts only when the
defrost thermostat is closed and the contactor is energized.
Defrost mode is identical to cooling mode except that outdoor fan
motor stops and second--stage heat is turned on to continue
warming conditioned spaces.
To initiate defrost, the defrost thermostat must be closed. This can
be accomplished as follows:
1. Turn off power to outdoor unit.
2. Disconnect outdoor fan motor lead from OF2 on control
board, see Fig. 12. Tape lead to prevent grounding.
3. Restart unit in heating mode, allowing frost to accumulate on
outdoor coil.
4. After a few minutes in heating mode, liquid line temperature
should drop below closing point of defrost thermostat
(approximately 30°F).
5. Short between speedup terminals with a flat--blade
screwdriver. This reduces the timing sequence to 1/256th of
original time. (See Table 3.)
6. When you hear reversing valve change position, remove
screwdriver immediately; otherwise, control will terminate
normal 10--minute defrost cycle in approximately 2 seconds.
NOTE: Length of defrost cycle is dependent upon length of time
it takes to remove screwdriver from test pins after reversing valve
has shifted.
7. Unit will remain in defrost for remainder of defrost cycle time
or until defrost thermostat reopens at approximately 65°Fcoil
temperature of liquid line.
8. Turn off power to outdoor unit and reconnect fan motor lead
to OF2 on control board.
Table 3—Defrost Control Speedup--Timing Sequence
PARAMETER
MINIMUM
(MINUTES)
MAXIMUM
(MINUTES)
SPEEDUP
(NOMINAL)
30--minute cycle 27 33 7sec
50--minute cycle 45 55 12 sec
90--minute cycle 81 99 21 sec
10--minute cycle 911 2sec
5 minutes 4.5 5.5 1sec
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12
Step 13.—Check Charge
Factory charge and charging method are shown on unit rating
plate. To check charge in cooling mode, refer to Cooling Only
Procedure. To check charge in heating mode, refer to Heating
Check Chart Procedure.
With unit operating, charge Puron units with liquid using a
commercial type metering device in manifold hose. Charge
refrigerant into suction line. Some refrigerant cylinders may
contain a dip tube that allows liquid refrigerant to flow from
cylinder in upright position. Check cylinder label for correct
position to allow liquid flow.
COOLING ONLY PROCEDURE
NOTE: If subcooling charging conditions are not favorable,
charge must be weighed in accordance with unit rating plate,
±0.6 oz/ft of 3/8 in. liquid line above or below 15 ft,
respectively. Favorable conditions fall within the ranges given on
the charging chart on the outdoor unit plate.
EXAMPLE:
To calculate additional charge required for a 25---ft. line set:
25 ft. --- 15 ft. = 10 ft. X 0.6 oz/ft. = 6 oz. of additional
charge.
Units installed with cooling mode TXV require charging with the
subcooling method.
1. Operate unit a minimum of 10 minutes before checking
charge.
2. Measure liquid service valve pressure by attaching an accurate
gage to service port.
3. Measure liquid line temperature by attaching an accurate
thermistor type or electronic thermometer to liquid line near
outdoor coil.
4. Refer to unit rating plate for required subcooling temperature.
5. Refer to Table 4. Find the point where required subcooling
temperature intersects measured liquid service valve pressure.
6. To obtain required subcooling temperature at a specific liquid
line pressure, add refrigerant if liquid line temperature is higher
than indicated or reclaim refrigerant if temperature is lower.
Allow a tolerance of ±3°F.
HEATING CHECK CHART PROCEDURE
To check system operation during heating cycle, refer to the
Heating Check Chart on outdoor unit. This chart indicates
whether a correct relationship exists between system operating
pressure and air temperature entering indoor and outdoor units. If
pressure and temperature do not match on chart, system
refrigerant charge may not be correct. Do not use chart to adjust
refrigerant charge.
NOTE: In heating mode, check refrigerant charge only when
pressures are stable. If in doubt, remove charge and weigh in
correct refrigerant charge.
NOTE: When charging is necessary during heating season,
charge must be weight in accordance with unit rating plate ±0.6
oz/ft of 3/8 in. liquid line above or below 15 ft, respectively.
EXAMPLE:
To calculate additional charge required for a 25---ft. line set:
25 ft. --- 15 ft. = 10 ft. X 0.6 oz/ft. = 6 oz. of additional
charge.
Step 14.—Final Checks
IMPORTANT: Before leaving job, be sure to do the following:
1. Ensure that all wiring is routed away from tubing and sheet
metal edges to prevent rub--through or wire pinching.
2. Ensure that all wiring and tubing is secure in unit before
adding panels and covers. Securely fasten all panels and covers.
3. Tighten service valve stem caps to 1/12--turn past finger tight.
4. Leave Users Manual with owner. Explain system operation
and periodic maintenance requirements outlined in manual.
5. Fill out Dealer Installation Checklist and place in customer
file.
CARE AND MAINTENANCE
For continuing high performance and to minimize possible
equipment failure, periodic maintenance must be performed on
this equipment.
Frequency of maintenance may vary depending upon geographic
areas, such as coastal applications. See Users Manual for
information.
25HBA

13
Table 4—Required Liquid--Line Temperature
Liquid
Pressure
at Service
Valve
Required Subcooling Temperature ( °F)
(PSIG) 510 15 20
174 56 51 46 41
181 58 53 48 43
188 61 56 51 46
195 63 58 53 48
202 65 60 55 50
209 67 62 57 52
216 69 64 59 54
223 71 66 61 56
230 73 68 63 58
237 75 70 65 60
244 77 72 67 62
251 79 74 69 64
258 81 76 71 66
265 82 77 72 67
272 84 79 74 69
279 86 81 76 71
286 88 83 78 73
293 89 84 79 74
300 91 86 81 76
307 93 88 83 78
314 94 89 84 79
321 96 91 86 81
328 97 92 87 82
335 99 94 89 84
342 100 95 90 85
349 102 97 92 87
356 103 98 93 88
363 105 100 95 90
370 106 101 96 91
377 107 102 97 92
384 109 104 99 94
391 110 105 100 95
398 112 107 102 97
405 113 108 103 98
412 114 109 104 99
419 115 110 105 100
426 117 112 107 102
433 118 113 108 103
440 119 114 109 104
447 120 115 110 105
454 122 117 112 107
461 123 118 113 108
468 124 119 114 109
475 125 120 115 110
482 126 121 116 111
Liquid
Pressure
at Service
Valve
Required Subcooling Temperature ( °F)
(PSIG) 510 15 20
489 127 122 117 112
496 129 124 119 114
503 130 125 120 115
510 131 126 121 116
517 132 127 122 117
524 133 128 123 118
531 134 129 124 119
538 135 130 125 120
545 136 131 126 121
552 137 132 127 122
559 138 133 128 123
566 139 134 129 124
573 140 135 130 125
580 141 136 131 126
587 142 137 132 127
594 143 138 133 128
601 144 139 134 129
608 145 140 135 130
25HBA

14
PURON(R---410A) QUICK REFERENCE GUIDE
SPuronrefrigerant operates at 50 ---70 percent higher pressures than R --- 22. Be sure that servicing equipment and replacement
components are designed to operate with Puron
SPuronrefrigerant cylinders are rose colored.
SRecovery cylinder service pressure rating must be 400 psig, DOT 4BA400 or DOT BW400.
SPuronsystems should be charged with liquid refrigerant. Use a commercial type metering device in the manifold hose when
charging into suction line with compressor operating
SManifold sets should be 700 psig high side and 180 psig low side with 550 psig low---side retard.
SUse hoses with 700 psig service pressure rating.
SLeak detectors should be designed to detect HFC refrigerant.
SPuron,aswithotherHFCs,isonlycompatiblewithPOEoils.
SVacuum pumps will not remove moisture from oil.
SDo not use liquid---line filter driers with rated working pressures less than 600 psig.
SDo not leave Puronsuction line filter driers in line longer than 72 hours.
SDo not install a suction---line filter drier in liquid line.
SPOE oils absorb moisture rapidly. Do not expose oil to atmosphere.
SPOE oils may cause damage to certain plastics and roofing materials.
SWrap all filter driers and service valves with wet cloth when brazing.
SA factory approved liquid---line filter drier is required on every unit.
SD o N O T u s e a n R --- 2 2 T X V.
SIf indoor unit is equipped with an R ---22 TXV or piston metering device, it must be changed to a hard shutoff PuronTXV.
SNever open system to atmosphere while it is under a vacuum.
SWhen system must be opened for service, recover refrigerant, evacuate then break vacuum with dry nitrogen and replace filter
driers. Evacuate to 500 microns prior to recharging.
SDonotventPuroninto the atmosphere.
SDo not use capillary tube coils.
SObserve all warnings,cautions,andbold text.
SAll indoor coils must be installed with a hard shutoff PuronTXV metering device.
Copyright 2005 Carrier Corp. S7310 W. Morris St. SIndianapolis, IN 46231
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations. Catalog No: 25HBA--- 1SI Replaces: NEW
Printed in U.S.A. Edition Date: 11/05
25HBA