International comfort products NXA6 User manual

Specifications subject to change without notice. 421 01 5501 02 9/29/15
INSTALLATION INSTRUCTIONS
R−410A Split System Air Conditioners
NXA6, N4A6, N4A5, R4A5, WCA5, NXA4,
N4A4, R4A4, WCA4, N4A3, R4A3, WCA3
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 current editions of the National Electrical
Code (NEC) NFPA 70. In Canada, refer to current editions of
the Canadian electrical code CSA 22.1.
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
would 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.
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
GENERAL
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. 1.)
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. 1.)
8. Ensure that tubing insulation is pliable and completely
surrounds vapor tube.
9. When necessary, use hanger straps which are 1 in.
(25.4 mm) wide and conform to shape of tubing
insulation. (See Fig. 1.)
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” (25.4 mm) MIN.
SUSPENSION
A94026
Fig. 1 −Piping Installation

Specifications subject to change without notice.
3421 01 5501 02
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 long line. Refer to Long
Line Application Guideline for further information.
IMPORTANT: Always install the factory−supplied liquid−line
filter drier. If replacing the filter drier, refer to Specification
Sheets for appropriate part number. Obtain replacement filter
driers from your distributor or branch.
INSTALLATION
IMPORTANT: Effective January 1, 2015, all split system and
packaged air conditioners must be installed pursuant to
applicable regional efficiency standards issued by the
Department of Energy.
CUT HAZARD
Failure to follow this caution may result in personal
injury.
Sheet metal parts may have sharp edges or burrs. Use
care and wear appropriate protective clothing and
gloves when handling parts.
CAUTION
!
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.
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. 2 to determine base pan size and knockout
hole location.
For hurricane tie downs, contact local distributor for details
and PE (Professional Engineer) certification, if required by
local authorities.
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 may require wind
baffles. Consult the Application Guideline and 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 ,.±9.5
mm/m) per compressor manufacturer specifications.
Clearance Requirements
When installing, allow sufficient space for airflow clearance,
wiring, refrigerant piping, and service. Allow 24 in. (609.6
mm) clearance to service end of unit and 48 in. (1219.2 mm)
(above unit. For proper airflow, a 6−in. (152.4 mm) clearance
on 1 side of unit and 12−in. (304.8 mm) on all remaining
sides must be maintained. Maintain a distance of 24 in.
(609.6 mm) between units or 18 in. (457.2 mm) if no
overhang within 12 ft. (3.66 m) Position so water, snow, or
ice from roof or eaves cannot fall directly on unit.
NOTE: 18” (457.2 mm) clearance option described
above is approved for outdoor units with wire grille coil
guard only. Units with louver panels require 24” (609.6
mm) between units.
On rooftop applications, locate unit at least 6 in. (152.4 mm)
above roof surface.
Operating Ambient
The minimum outdoor operating ambient in cooling mode
without accessory is 55_F (12.78_C), and the maximum
outdoor operating ambient in cooling mode is 125_F
(51.67_C).
Make Piping Connections
!WARNING
PERSONAL INJURY AND ENVIRONMENTAL
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. Use all service ports
and open all flow−control devices, including solenoid
valves.
Federal regulations require that you do not vent
refrigerant to the atmosphere. Recover during system
repair or final unit disposal.
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
(152.4 mm). vertical rise at service valve. Refrigerant
tubing lengths up to 36−in (914.4 mm). may be buried
without further special consideration. Do not bury
lines more than 36−in. (914.4 mm).
3/8-in. (9.53 mm) Dia.
Tiedown Knockouts in
Basepan(2) Places
View From Top
UNIT BASE PAN
Dimension in. (mm)
TIEDOWN KNOCKOUT LOCATIONS in. (mm)
A B C
23-1/2 X 23-1/2
(596.9 X 596.9) 7-13/16 (198.4) 4–7/16 (112.7) 18–1/16 (458.8)
26 X 26
(660.4 X 660.4) 9–1/8 (231.8) 4–7/16 (112.7) 21–1/4 (539.8)
31–1/2 X 31–1/2
(800.1 X 800.1) 9–1/8 (231.8) 6–9/16 (166.7) 24–11/16 (627.1)
35 X 35
(889 X 889) 9–1/8 (231.8) 6–9/16 (166.7) 28–7/16 (722.3)
A05177
Fig. 2 −Tiedown Knockout Locations
Outdoor units may be connected to indoor section using
accessory tubing package or field−supplied refrigerant grade
tubing of correct size and condition. Rated tubing diameters

Specifications subject to change without notice.
421 01 5501 02 4
shown in Table 1 are recommended up to 80 ft. (24.38 m).
See Specification Sheets for acceptable alternate vapor
diameters and associated capacity losses. For tubing
requirements beyond 80 ft. (24.38 m), substantial capacity
and performance losses can occur. Following the
recommendations in the Long Line Application Guideline
will reduce these losses. Refer to Table 1 for field tubing
diameters. Refer to Table 5 for accessory requirements.
There are no buried−line applications greater than 36−in.
(914.4 mm) allowed.
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.
Outdoor Unit Connected to Factory Approved
Indoor Unit
Outdoor unit contains correct system refrigerant charge for
operation with factory approved AHRI rated indoor unit when
connected by 15 ft. (4.57 m) of field−supplied or
factory−accessory tubing, and factory supplied filter drier.
Check refrigerant charge for maximum efficiency.
NOTE: Some units may require additional charge amounts
for 15 ft (4.57 m) line sets. Refer to the chart in the Check
Charge section for further instructions.
Refrigerant Tubing Connection Outdoor
Connect vapor and liquid tubes to fittings on vapor and liquid
service valves (see Table 1.) Use refrigerant grade tubing
Sweat Connection
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Service valves must be wrapped in a heat−sinking
material such as a wet cloth while brazing.
Use refrigeration grade tubing. Service valves are closed
from factory and ready for brazing. After wrapping service
valve with a wet cloth, braze sweat connections using
industry accepted methods and materials. Consult local code
requirements. Refrigerant tubing and indoor coil are now
ready for leak testing. This check should include all field and
factory joints.
Table 1 – Refrigerant Connections and Recommended
Liquid and Vapor Tube Diameters (In.)
UNIT SIZE
LIQUID RATED VAPOR*
Connection
& Max. Tube
Diameter
Connection
Diameter
Tube
Diameter
18, 24 3/8 3/4 3/4
30 3/8 3/4 3/4
36 3/8 7/8 7/8
42, 48 3/8 7/8 7/8
60 3/8 7/8 1-1/8
* Units are rated with 25 ft. (7.6 m) of lineset. See Specification sheet for
performance data when using different size and length linesets.
Notes:
1. Do not apply capillary tube or fixed orifice indoor coils to these units.
2. For Tubing Set lengths between 50 and 200 ft. (15.2 and 61.0 m)
horizontal or 20 ft. (6.1 m) vertical differential 250 ft. (76.2 m) Total
Equivalent Length), refer to the Long Line Application Guideline
3. For alternate liquid line options on 18−42 size units, see Specification
Sheet or
Long Line Application Guideline
Install Liquid−Line Filter Drier Indoor
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
1. Installation of filter drier in liquid line is required.
2. Filter drier must be wrapped in a heat−sinking
material such as a wet cloth while brazing.
Refer to Fig. 3 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 above 5−in. (127 mm) liquid tube.
Flow arrow must point towards indoor coil.
4. Connect and braze liquid refrigerant tube to the filter
drier.
A05178
Fig. 3 −Liquid Line Filter Drier
Evacuate Refrigerant Tubing and Indoor Coil
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Never use the system compressor as a vacuum
pump.
Refrigerant tubes and indoor coil should be evacuated using
the recommended deep vacuum method of 500 microns.
The alternate triple evacuation method may be used (see
triple evacuation procedure in service manual). Always
break a vacuum with dry nitrogen.
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. A tight dry system will
hold a vacuum of 1000 microns after approximately 7
minutes. See Fig. 4.
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. 4 −Deep Vacuum Graph

Specifications subject to change without notice.
5421 01 5501 02
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 or wires. Pay close attention to feeder tubes,
making sure wire ties on feeder tubes are secure and tight.
Installing with Indoor Piston
Air Conditioner Matched with Factory Approved Piston
Indoor
Air conditioners may be installed with piston fan coils as a
system when the air conditioner and fan coil are listed as a
system in the AHRI directory. All rated piston fan coils are
shipped with the appropriate size piston for the equal
tonnage air conditioner. Matching air conditioners with piston
indoors of larger tonnage size requires a TXV.
Air Conditioner Applied as Replacement Component
If the air conditioner is installed as a replacement component
in an existing piston indoor system, the piston size in the
indoor unit should be changed to the size required for the air
conditioner which can be found in the Specification Sheet.
CAUTION
!
PRODUCT OPERATION HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
If using a TXV in conjunction with a single−phase
reciprocating compressor, a compressor start
capacitor and relay are required.
Units with Cooling Mode TXV
Units installed with cooling mode TXV require charging by
the subcooling method.
1. Operate unit a minimum of 15 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 2 −Rating Plate (required) Subcooling
Temperature. 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 ("1.7_C).
Units with Indoor Piston
Units installed with indoor pistons require charging by the
superheat method.
The following procedure is valid when indoor airflow is within
"21 percent of its rated CFM.
1. Operate unit a minimum of 15 minutes before
checking charge.
2. Measure suction pressure by attaching an accurate
gage to suction valve service port.
3. Measure suction temperature by attaching an accurate
thermistor type or electronic thermometer to suction
line at service valve.
4. Measure outdoor air dry bulb temperature with
thermometer.
5. Measure indoor air (entering indoor coil) wet−bulb
temperature with a sling psychrometer.
6. Refer to Table 3 −Superheat Charging −AC Only.
Find outdoor temperature and evaporator entering air
wet−bulb temperature. At this intersection, note
superheat. Where a dash (−−) appears on the table,
do not attempt to charge system under these
conditions or refrigerant slugging may occur. Charge
must be weighted in, adding or removing 0.6 oz/ft of
3/8 liquid line above or below 15 feet (4.6m)
respectively.
7. Refer to Table 4 −Required Suction−Line
Temperature. Find superheat temperature (from #6
above) and suction pressure. At this intersection, note
suction line temperature.
8. If unit has a higher suction line temperature than
charted temperature, add refrigerant until charted
temperature is reached.
9. If unit has a lower suction line temperature than
charted temperature, reclaim refrigerant until charted
temperature is reached.
10. When adding refrigerant, charge in liquid form into
suction service port using a flow−restricting device.
11. If outdoor air temperature or pressure at suction valve
changes, charge to new suction line temperature
indicated on chart.
12. Optimum performance will be achieved when the
operating charge produces 10_F suction superheat at
suction service valve with 95_F (35_C) outdoor
ambient and 80_F (27_C) dry bulb (67_F / 19_C) wet
bulb) indoor temperature (DOE “A” test conditions) at
rated airflow.

Specifications subject to change without notice.
421 01 5501 02 6
Table 2 – Rating Plate (required) Subcooling Temperatures
Measure
Liquid Pressure
(psig)
R-410A Required Liquid Line Temperature _F (_C)
_F (_C) _F (_C) _F (_C) _F (_C) _F (_C) _F (_C)
6 3 8 4 10 6 12 7 14 8 16 9
251 78 26 76 24 74 23 72 22 70 21 68 20
259 80 27 78 26 76 24 74 23 72 22 70 21
266 82 28 80 27 78 26 76 24 74 23 72 22
274 84 29 82 28 80 27 78 26 76 24 74 23
283 86 30 84 29 82 28 80 27 78 26 76 24
291 88 31 86 30 84 29 82 28 80 27 78 26
299 90 32 88 31 86 30 84 29 82 28 80 27
308 92 33 90 32 88 31 86 30 84 29 82 28
317 94 34 92 33 90 32 88 31 86 30 84 29
326 96 36 94 34 92 33 90 32 88 31 86 30
335 98 37 96 36 94 34 92 33 90 32 88 31
345 100 38 98 37 96 36 94 34 92 33 90 32
364 104 40 102 39 100 38 98 37 96 36 94 34
374 106 41 104 40 102 39 100 38 98 37 96 36
384 108 42 106 41 104 40 102 39 100 38 98 37
395 110 43 108 42 106 41 104 40 102 39 100 38
406 112 44 110 43 108 42 106 41 104 40 102 39
416 114 46 112 44 110 43 108 42 106 41 104 40
427 116 47 114 46 112 44 110 43 108 42 106 41
439 118 48 116 47 114 46 112 44 110 43 108 42
450 120 49 118 48 116 47 114 46 112 44 110 43
462 122 50 120 49 118 48 116 47 114 46 112 44
474 124 51 122 50 120 49 118 48 116 47 114 46
Table 3 – Superheat Charging −AC Only
OUTDOOR TEMP (_F)
EVAPORATOR ENTERING AIR TEMPERATURE (_F WB)
50 52 54 56 58 60 62 64 67 68 70 72 74 76
55 9 12 14 17 20 23 26 29 32 35 37 40 42 45
60 7 10 12 15 18 21 24 27 30 33 35 38 40 43
65 — 6 10 13 16 19 21 24 27 30 33 36 38 41
70 — — 7 10 13 16 19 21 24 27 30 33 36 39
75 — — — 6 9 12 15 18 21 24 28 31 34 37
80 — — — — 5 8 12 15 18 21 25 28 31 35
85 — — — — — — 8 11 15 19 22 26 30 33
90 — — — — — — 5 9 13 16 20 24 27 31
95 — — — — — — — 6 10 14 18 22 25 29
100 — — — — — — — — 8 12 15 20 23 27
105 — — — — — — — — 5 9 13 17 22 26
110 — — — — — — — — — 6 11 15 20 25
115 — — — — — — — — — — 8 14 18 23
*Optimum performance point, 95_F (35_C) outdoor ambient and (80_F / 27_C dry bulb), (67_F / 19_C wet bulb) indoor conditions. (DOE A Test Conditions)
Where a dash (−−) appears do not attempt to charge system under these conditions or refrigerant slugging may occur. Charge must be weighed in.
Note: Superheat _F is at low−side service port, Allow a tolerance of "3_F ("1.7_C)
Note: Indoor dry bulb between 70_F and 80_F (21_C and 27_C)

Specifications subject to change without notice.
7421 01 5501 02
Table 4 – Required Suction−Line Temperature
SUPERHEAT TEMP (_F)
SUCTION PRESSURE AT SERVICE PORT (PSIG)
107.8 112.2 116.8 121.2 126 130.8 138.8 140.8 145.8
035 37 39 41 43 45 47 49 51
237 39 41 43 45 47 49 51 53
439 41 43 45 47 49 51 53 55
641 43 45 47 49 51 53 55 57
843 45 47 49 51 53 55 57 59
10 45 47 49 51 53 55 57 59 61
12 47 49 51 53 55 57 59 61 63
14 49 51 53 55 57 59 61 63 65
16 51 53 55 57 59 61 63 65 67
18 53 55 57 59 61 63 65 67 69
20 55 57 59 61 63 65 67 69 71
22 57 59 61 63 65 67 69 71 73
24 59 61 63 65 67 69 71 73 75
26 61 63 65 67 69 71 73 75 77
28 63 65 67 69 71 73 75 77 79
30 65 67 69 71 73 75 77 79 81
32 67 69 71 73 75 77 79 81 83
34 69 71 73 75 77 79 81 83 85
36 71 73 75 77 79 81 83 85 87
38 73 75 77 79 81 83 85 87 89
40 75 77 79 81 83 85 87 89 91
Make Electrical Connections
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 unit in 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.
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. 5.
DISCONNECT
PER N.E.C. AND/OR
LOCAL CODES
CONTACTOR
GROUND
LUG
FIELD GROUND
WIRING
FIELD POWER
WIRING
BLUE
3 PHASE ONLY
A94025
Fig. 5 −Line Connections
Connect Control Wiring
Route 24−v control wires through control wiring grommet and
connect leads to control wiring (See Fig. 7). Refer to
Installation Instructions packaged with thermostat.
Use No. 18 AWG color−coded, insulated (35_C minimum)
wire. If thermostat is located more than 100 ft. (30.48 m)
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 2 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.

Specifications subject to change without notice.
421 01 5501 02 8
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.
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. (24.38 m). Refer to the Long Line Application
Guideline.
Install Electrical Accessories
Refer to the individual instructions packaged with kits or
accessories when installing.
Start−Up
CAUTION
!
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this caution may result in personal injury,
equipment damage or improper operation.
SDo not overcharge system with refrigerant.
SDo not operate unit in a vacuum or at negative
pressure.
SCompressor dome temperatures may be hot.
CAUTION
!
PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal
injury.
Wear safety glasses, protective clothing, and gloves
when handling refrigerant and observe the following:
SFront seating service valves are equipped with
Schrader valves.
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) front seated (closed)
and caps installed. Replace stem caps after system is
opened to refrigerant flow. 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 COOL and fan control to ON or
AUTO mode, as desired. Operate unit for 15 minutes.
Check system refrigerant charge.
3−Phase Monitor
In 3−phase units a small circuit board is factory installed to
monitor line voltage. A small led will flash if a phase problem
exists. See code descriptions on monitor. If LED is flashing,
disconnect power to unit and interchange 2 field−wiring leads
on unit contactor.
A00010
Fig. 6 −3−Phase Monitor Control
(Applies to 3−Phase Units Only)
Table 5 – Three−Phase Monitor LED Indicators
LED STATUS
OFF No call for compressor operation
FLASHING Reversed phase
ON Normal
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Ensure compressor rotation is correct.
S3−phase scroll compressors are rotation sensitive.
SA flash LED on phase monitor indicates reverse
rotation. (See Table 3)
This will not allow contractor to be energized.
SDisconnect power to unit and interchange 2
field−wiring leads on unit contactor.
CAUTION
!
Sequence of Operation
Turn on power to indoor and outdoor units. Transformer is
energized.
On a call for cooling, thermostat makes circuits R−Y and
R−G. 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 stop.
If indoor unit is equipped with a time−delay relay circuit, the
indoor blower will run an additional 90 seconds to increase
system efficiency.
Check Charge
Factory charge amount and desired subcooling are shown
on unit rating plate. Charging method is shown on
information plate inside unit. To properly check or adjust
charge, conditions must be favorable for subcooling
charging. Favorable conditions exist when the outdoor
temperature is between 70_F and 100_F (21.11_C and
37.78_C), and the indoor temperature is between 70_F and
80_F (21.11_C and 26.67_C).
Follow the procedure below:
Adjust charge by adding or removing 0.6 oz/ft of 3/8 liquid
line above or below 15ft (4.57 m) respectively.

Specifications subject to change without notice.
9421 01 5501 02
Unit
Size
15 ft. (4.57 m) Line Set Charge lb (kg)
13 SEER 14 SEER
14 SEER
COASTAL
SOUTHWEST
14/15 SEER
SOUTHWEST/NORTH
16 SEER
SOUTHWEST
16 SEER
18 4.10 (1.86) 4.77 (2.16) 4.5 (2.04) 4.87 (2.21) 4.61 (2.09) 3.83 (1.74)
24 4.22 (1.91) 4.20 (1.91) 4.20 (1.91) 4.60 (2.09) 6.00 (2.72) 4.95 (2.25)
30 4.90 (2.22) 5.67 (2.57) 5.67 (2.57) 5.67 (2.57) 6.81 (3.09) 6.82 (3.09)
36 5.00 (2.27) 5.42 (2.46) 5.42 (2.46) 6.40 (2.90) 7.00 (3.18) 6.75 (3.06)
42 6.07 (2.75) 7.90 (3.58) 7.90 (3.58) 7.46 (3.38) 8.62 (3.91) 8.60 (3.90)
48 7.00 (3.18) 8.31 (3.77) 8.31 (3.77) 8.31 (3.77) 13.00 (5.90) 13.00 (5.90)
60 8.80 (3.99) 9.39 (4.26) 9.39 (4.26) 9.39 (4.26) 14.50 (6.58) 14.50 (6.58)
NOTE: For 15 ft (4.57 m) line set charge, refer to the table
above. some units may require additional charge depending
on size. Find model size in chart below, reference factory
charge on unit’s rating plate and add additional charge if
there is a difference. Additional charge will be needed for
longer line sets (charge unit to nameplate subcooling).
For standard refrigerant line lengths (80 ft/24.38 m or less),
allow system to operate in cooling mode at least 15 minutes.
If conditions are favorable, check system charge by
subcooling method. If any adjustment is necessary, adjust
charge slowly and allow system to operate for 15 minutes to
stabilize before declaring a properly charged system.
If the indoor temperature is above 80_F (26.67_C), and the
outdoor temperature is in the favorable range, adjust system
charge by weight based on line length and allow the indoor
temperature to drop to 80_F (26.67_C) before attempting to
check system charge by subcooling method as described
above.
If the indoor temperature is below 70_F (21.11_C), or the
outdoor temperature is not in the favorable range, adjust
charge for line set length above or below 15ft (4.57 m) only.
Charge level should then be appropriate for the system to
achieve rated capacity. The charge level could then be
checked at another time when the both indoor and outdoor
temperatures are in a more favorable range.
NOTE: If line length is beyond 80 ft (24.38 m) or greater
than 20 ft (6.10 m) vertical separation, see Long Line
Application Guideline for special charging requirements.
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 Owner’s Manual with owner. Explain system
operation and periodic maintenance requirements
outlined in manual.
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
Owner’s Manual for information.
Table 6 – Accessory Usage
ACCESSORY
REQUIRED FOR LOW-AMBIENT
COOLING APPLICATIONS
(Below 55°F/12.8_C)
REQUIRED FOR LONG LINE
APPLICATIONS*
REQUIRED FOR
SEA COAST
APPLICATIONS
(Within 2 miles/3.22 km)
Compressor Start Assist Capacitor and Relay Ye s Ye s No
Crankcase Heater Ye s Ye s No
Evaporator Freeze Thermostat Ye s No No
Hard Shut-Off TXV Ye s Yes‡ No
Liquid Line Solenoid Valve No No No
Low-ambient Pressure Switch Ye s No No
Support Feet Recommended No Recommended
Winter Start Control Ye s No No
* For tubing line sets between 50 and 200 ft. (15.24 and 60.96 m) and/or 20 ft. (6.10 m) vertical differential, refer to Long Line Application Guideline.
‡TXV required beyond 20 ft. (6.1 m) vertical separation or 50 ft. (15.2 m) total length.

Specifications subject to change without notice.
421 01 5501 02 10
24 VAC HOT
24 VAC COM
R
C
G
W/W1
Y/Y2
R
C
C
A/C
THERMOSTAT
Typical
FAN COIL
AIR
CONDITIONER
G
W2
HEAT STAGE 1
COOL STAGE 1
INDOOR FAN
24 VAC HOT
24 VAC COM
R
C
G
W/W1
Y/Y2
R
C
C
A/C
THERMOSTAT
Typical
FURNACE
AIR
CONDITIONER
Y
G
W
HEAT STAGE 1
COOL STAGE 1
INDOOR FAN
A02326
LEGEND
24-V FACTORY WIRING
24-V FIELD WIRING
FIELD SPLICE CONNECTION
CONTACTOR
C
A97368
Fig. 7 −Generic Wiring Diagrams
(See Thermostat Installation Instruction
for specific unit combinations)
R−410A REFRIGERANT QUICK REFERENCE GUIDE
SR−410A refrigerant operates at 50−70 percent higher pressures than R−22. Be sure that servicing equipment and
replacement components are designed to operate with R−410A refrigerant
SR−410A refrigerant cylinders are rose colored.
SRecovery cylinder service pressure rating must be 400 psig, DOT 4BA400 or DOT BW400.
SR−410A refrigerant 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.
SR−410A refrigerant, as with other HFCs, is only compatible with POE oils.
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 R−410A 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.
SDo NOT use an R−22 TXV.
SIf indoor unit is equipped with an R−22 TXV or piston metering device, it must be changed to a hard shutoff R−410A
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.
SDo not vent R−410A refrigerant into the atmosphere.
SDo not use capillary tube coils.
SObserve all warnings, cautions, and bold text.
Copyright 2015 International Comfort Products
Lewisburg, TN 37091 USA