Bryant CHS072 User manual

506 01 2303 01 10/2019
Specifications are subject to change without notice.
INSTALLATION INSTRUCTIONS
R--410A Split System Heat Pump
CHS072 -- 121
NOTE: Read the entire instruction manual before starting
the installation
TABLE OF CONTENTS
SAFETY CONSIDERATIONS 2....................
INSTALLATION GUIDELINES 3..................
Rated Indoor Airflow (cfm) 3.....................
INSTALLATION 7 -- 14...........................
Jobsite Survey 7................................
Step 1 -- Plan for Unit Location 7..................
Step 2 -- Complete Pre--Installation Checks 8.........
Step3–PrepareUnitMounting Support 8...........
Step 4 -- Rig and Mount the Unit 8.................
Step 5 -- Complete Refrigerant Piping Connections 8...
Step 6 -- Install Accessories 12....................
Step 7 -- Complete Electrical Connections 12.........
Step 8 -- Wind Baffles for Low Ambient Control 14...
PRE-START-UP 16...............................
System Checks 16..............................
Turn On Crankcase Heaters 16....................
Preliminary Charge 16...........................
START--UP 16 -- 25..............................
CHS Units 16..................................
OPERATING SEQUENCE 26......................
Indoor (Supply) Fan 26..........................
Cooling Unit Without Economizer 26...............
Cooling Unit With Economizer 27.................
Heating 27....................................
Defrost Cycle 27...............................
Supplemental Heating/Emergency Heating 28........
Cooling and Heating Shutdown 28.................
ROUTINE SYSTEM MAINTENANCE 28............
Quarterly Inspection
(and 30 days after initial start) 28..................
SERVICE 29 - 42................................
Refrigeration System 29.........................
Compressor Oil 29..............................
Servicing Systems on Roofs
with Synthetic Materials 29.......................
Liquid Line Filter Driers 29.......................
Filed Refrigerant Access Ports 29..................
Outdoor Coil Metering Devices 29.................
Refrigerant System Pressure Access Ports 30.........
Compressor Protection 30........................
Crankcase Heater 30............................
Commercial Defrost Board 30.....................
Comfort Alert Diagnostic Module 38...............
Lubrication 40.................................
Outdoor Coil Maintenance and
Cleaning Recommendations 40....................
Fastener Torque Values 42........................
TROUBLESHOOTING 43.........................
APPENDIX A
Air Conditioner and Heat Pump with R--410A –
Quick Reference Guide 44........................
APPENDIX B
Wiring Diagram List 45..........................
APPENDIX C
Low Ambient Option — Factory Installed 46.........
START--UP CHECKLIST 51 -- 52...................

2506 01 2303 01
Specifications are subject to change without notice.
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service,
maintenance, or use can cause explosion, fire, electrical
shock or other conditions which may cause 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 and work
gloves. Use quenching cloths for brazing operations and
have a fire extinguisher available. Read these instructions
thoroughly and follow all warnings or cautions attached to
the unit. Consult local building codes and appropriate
national electrical codes (in USA, ANSI/NFPA 70,
National Electrical Code (NEC); in Canada, CSA C22.1)
for special requirements.
It is important to 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 the signal words DANGER, WARNING,
CAUTION, and NOTE. 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.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could cause personal
injury or death.
Before performing service or maintenance operations
on unit, turn off main power switch to unit and install
lock(s) and lockout tag(s). Ensure electrical service to
rooftop unit agrees with voltage and amperage listed
on the unit rating plate. Unit may have more than one
power switch.
!WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal
injury, death and/or equipment damage.
R--410A refrigerant systems operate at higher
pressures than standard R--22 systems. Do not use
R--22 service equipment or components on R--410A
refrigerant equipment.
!WARNING
PERSONAL INJURY AND ENVIRONMENTAL
HAZARD
Failure to follow this warning could cause personal
injury or death.
Relieve pressure and recover all refrigerant before
system repair or final unit disposal.
Wear safety glasses and gloves when handling
refrigerants. Keep torches and other ignition sources
away from refrigerants and oils.
!WARNING
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, safety
glasses and gloves when handling parts and servicing
air conditioning equipment.
CAUTION
!

506 01 2303 01 3
Specifications are subject to change without notice.
INSTALLATION GUIDELINE
Replacement /Retrofit – R22 to R--410A
Split system heat pumps are intended to be installed with
matching indoor sections only. The CHS heat pump
outdoor units are matched only with same-size FHS
indoor sections. Existing R-22 indoor coils cannot be
converted to R-410A heat pump duty. Only the existing
refrigerant piping is a candidate for retrofit use.
Acid test – If the existing system is being replaced
because of a compressor electrical failure, assume acid is
in system. If system is being replaced for any other
reason, use an approved acid test kit to determine acid
level. If even low levels of acid are detected, install a 100
percent activated alumina suction line filter drier in
addition to the replacement liquid-line filter drier. Operate
this system in COOLING ONLY. Remove the suction line
filter drier as soon as possible, with a maximum of 72 hr
of operation.
Recommendation: Install a ball valve in the liquid line at
the filter drier location when installing a suction filter in
the suction line.
Evaluate existing refrigerant piping – Reuse of existing
refrigerant piping involves three issues: quality (strength) of
existing tubing, cleanliness and tube size. R--410A operates
at pressures that are 50 to 70% higher than the operating
pressures in R--22 systems. It is important that the existing
piping set be in excellent physical condition to be considered
suitable for re--use with R--410A. If the physical condition of
the existing piping set is not excellent, then remove the
existing piping and replace with new piping. Refer to Step 5
for a discussion on selecting pipe sizes for these CHS heat
pumps; refer to Table 2 for recommended pipe sizes.
If the existing piping set is suitable for re--use with
R--410A based on its condition, determine the relative
locations and elevation differences between outdoor
section (CHS) and indoor section (FHS) and then check
the sizes of the existing lines against the recommended
pipe sizes in Table 2 and the MAXIMUM vapor riser pipe
size use data in Table 3. Do not use pipe sizes that exceed
these maximum vapor riser sizes as oil return at part load
conditions in vertical rises may be an issue. Replace any
riser sections with reduced pipe sizes if existing pipe sizes
exceed these maximum tube size limits.
Installation –
1. Remove the existing evaporator coil or fan coil and
install the replacement coil.
2. Drain oil from low points and traps in vapor line
tubing if they were not replaced.
3. Remove the existing outdoor unit. Install the new out-
door unit according to these installation instructions.
4. Flush the interconnection piping system with dry
Nitrogen to eliminate as much trace of mineral oil as
possible.
5. Install the factory-supplied liquid-line filter drier at
the indoor coil just upstream of the TXV.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Never install suction--line filter drier in the liquid--line
of a R--410A refrigerant system.
CAUTION
!
6. If required, install a 100% activated alumina suction
line filter drier at the outdoor unit.
7. Evacuate and charge the system according to the in-
structions in this installation manual.
8. Operate the system for 10 hr. In COOLING MODE
ONLY. Monitor the pressure drop across the suction
line filter drier. If pressure drop exceeds 3 psig
(21kPa), replace suction-line and liquid-line filter
driers. Be sure to purge system with dry nitrogen and
evacuate when replacing filter driers. Continue to
monitor the pressure drop across suction-line filter
drier. Repeat filter changes is necessary. Never leave
suction-line filter drier in system longer than 72 hr
(actual time).
Rated Indoor Airflow (cfm)
The table below lists the rated indoor airflow used for the
AHRI efficiency rating for the units covered in this
document.
CHSwithFHS
Model Numbers Full Load Airflow (cfm)
CHS072*A/B --- FHS072 2400
CHS072*G/H --- FHS072 2400
CHS091 --- FHS090 3000
CHS121*A/B --- FHS120 3000
CHS121*G/H --- FhS120 3000

4506 01 2303 01
Specifications are subject to change without notice.
UNIT
Standard
Weight
Corner
A
Corner
B
Corner
C
Corner
DCenter of Gravity Unit Height
CHS072
444 201 134 61 97 44 90 41 123 56 22
[559]
25
[635]
13
[330]
42-3/8
[1076]
CHS091
483 219 162 74 110 50 85 39 125 57 20
[508]
24
[610]
21
[533]
42-3/8
[1076]
CHS121
575 261 186 84 126 57 106 48 157 71 21
[533]
24
[610]
23
[584]
50-3/8
[1280]
lbs. kg. lbs. kg. lbs. kg. lbs. kg. lbs. kg. X Y Z H
C150355
Fig. 1 -- CHS072--121 Unit Dimensions

506 01 2303 01 5
Specifications are subject to change without notice.
Table 1A — Physical Data — CHS072--121 Units — 60 Hz English
UNIT CHS072*A/B CHS072*G/H CHS091*A/B CHS121*A/B CHS121*G/H
NOMINAL CAPACITY (tons) 6 6 7.5 10 10
OPERATING WEIGHTS (lb)
Aluminum-Fin Coils 444 444 483 575 575
REFRIGERANT TYPE‡R-410A R-410A R-410A R-410A
Operating Charge (w/ fan coil), Typical (lb)†18.0 18.0 21.0 27.0 27.0
Shipping Charge (lb) 9.0 9.0 9.0 9.0 9.0
COMPRESSOR
Qty...Type 1...Scroll 1...2 Stage Scroll 1...Scroll 1...Scroll 2...Scroll
OUTDOOR FANS
Qty...Rpm 2...1100 2...1100 2...1100 2...1100 2...1100
Motor Hp 1/41/41/41/41/4
Diameter (in) 22 22 22 22 22
Nominal Airflow (Cfm Total) 6,000 6,000 6,000 6,000 6,000
Watts (Total) 610 610 610 610 610
OUTDOOR COIL (Qty) 1...Round Tube/Plate Fin (RTPF)
Face Area (sq ft total) 17.5 17.5 23.0 28.1 28.1
Rows/Fins per inch (FPI) 2/17 2/17 2/17 2/17 2/17
CONTROLS
Pressurestat Settings (psig)
High Cutout 630 10 630 10 630 10 630 10 630 10
Cut-in 505 20 505 20 505 20 505 20 505 20
Low Cutout 27 327 327 327 327 3
Cut-in 44 544 544 544 544 5
PIPING CONNECTIONS (in. ODS)
Qty...Vapor 1...11/81...11/81...11/81...13/81...13/8
Qty...Liquid 1...3/81...3/81...1/21...1/21...1/2
LEGEND
ODS — Outside Diameter Sweat (socket)
‡ Unit is factory-supplied with partial charge only.
† Typical operating charge with 25 ft of interconnecting piping.

6506 01 2303 01
Specifications are subject to change without notice.
Table 1B — Physical Data — CHS072--121 Units — 60 Hz SI
UNIT CHS072*A/B CHS072*G/H CHS091*A/B CHS121*A/B CHS121*G/H
NOMINAL CAPACITY (kW) 21.1 21.1 26.4 35.1 35.1
OPERATING WEIGHT (kg)
Aluminum-Fin Coils 201 201 219 261 261
REFRIGERANT TYPE‡R-410A R-410A R-410A R-410A R-410A
Operating Charge (w/ fan coil), Typical (kg)†8.2 8.2 9.5 12.2 12.2
Shipping Charge (kg) 4.1 4.1 4.1 4.1 4.1
COMPRESSOR
Qty...Type 1...Scroll 1...2 Stage Scroll 1...Scroll 1...Scroll 2...Scroll
OUTDOOR FANS
Qty...r/s 2...18 2...18 2...18 2...18 2...18
Motor Hp NEMA 1/41/41/41/41/4
Diameter (mm) 560 560 560 560 560
Nominal Airflow (L/s) 2832 2832 2832 2832 2832
Watts (Total) 610 610 610 610 610
OUTDOOR COIL (Qty) 1...Round Tube/Plate Fin (RTPF)
Face Area (sq m total) 1.6 1.6 2.1 2.6 2.6
Rows/Fins per Meter (Fins/m) 2/670 2/670 2/670 2/670 2/670
CONTROLS
Pressurestat Settings (kPa)
High Cutout 4344 70 4344 70 4344 70 4344 70 4344 70
Cut-in 3482 138 3482 138 3482 138 3482 138 3482 138
Low Cutout 186 21 186 21 186 21 186 21 186 21
Cut-in 303 35 303 35 303 35 303 35 303 35
PIPING CONNECTIONS (in. ODS)
Qty...Vapor 1...11/81...11/81...11/81...13/81...13/8
Qty...Liquid 1...3/81...3/81...1/21...1/21...1/2
LEGEND
NEMA — National Electrical Manufacturers Association
ODS — Outside Diameter Sweat (socket)
‡ Unit is factory-supplied with partial charge only.
† Typical operating charge with 7.62 m of interconnecting piping.

506 01 2303 01 7
Specifications are subject to change without notice.
MODEL SERIES CHS0 9 1HGA0A0 0 A
Position Number
12345678910111213
14
Type
Voltage
Refrigerant Options
Coil Options
A = None
C = Non-Fused Disconnect
0 = Electro-Mechanical Controls (standard)
0 = Not Used
Base Unit Controls
A = Cu/Al
B = Precoat Cu/Al
C = E−Coat Cu/Al
M = Cu/Al with Louvered Hail Guards
M = Precoat Cu/Al with Louvered Hail Guards
P = E−Coat Cu/Al with Louvered Hail Guards
Not Used
A = Original Design Sales Code
Efficiency
072 = 6 Tons
091 = 7.5 Tons
121 = 10 Tons
H = 208/230−3−60
L = 460−3−60
S = 575−3−60
0 = None
1 = Un-powered Convenience Outlet
A = Single Circuit
B = Single Circuit with Low Ambient Controller
G = Single Circuit / 2-Stage (072 and 121 units only)
H = Single Circuit / 2-Stage with Low Ambient Controller (072 and 121 units only)
C = R-410A Condensing Unit
H = Heat Pump
S= Standard Efficiency
Nominal Cooling Capacity
Service Options
Electrical Options
C150356
Fig. 2 -- Model Number Nomenclature
DESIGNATESPOSITION
Week of manufacture (fiscal calander)
Manufacturing location5
Sequence number
Year of manufacture (”15” = 2015)
1−2
6−10
3−4
POSITION NUMBER
TYPICAL
12345678910
0515C12345
C150336
Fig. 3 -- Serial Number Nomenclature
.INSTALLATION
Jobsite Survey
Complete the following checks before installation.
1. Consult local building codes and the NEC (National
Electrical Code) ANSI/NFPA 70 for special installa-
tion requirements.
2. Determine unit location (from project plans) or select
unit location.
3. Check for possible overhead obstructions which may
interfere with unit lifting or rigging.
Step 1 — Plan for Unit Location
Select a location for the unit and its support system (pad,
rails or other) that provides for the minimum clearances
required for safety. This includes the clearance to
combustible surfaces, unit performance and service access
below, around and above unit as specified in unit
drawings. See Fig. 4.
Select a unit mounting system that provides adequate
height to allow for removal and disposal of frost and ice
that will form during the heating-defrost mode.
NOTE: Consider also the effect of adjacent units on
airflow performance and control box safety clearance.

8506 01 2303 01
Specifications are subject to change without notice.
Do not install the outdoor unit in an area where fresh air
supply to the outdoor coil may be restricted or when
recirculation from the condenser fan discharge is possible.
Do not locate the unit in a well or next to high walls.
Evaluate the path and required line length for
interconnecting refrigeration piping, including vapor riser
requirements and liquid line lift; a heat pump system will
have one of each type in opposite modes. Relocate
sections to minimize the length of interconnecting tubing.
DO NOT BURY REFRIGERATION LINES.
Although unit is weatherproof, avoid locations that permit
water from higher level runoff and overhangs to fall onto
the unit.
REAR:
Min 18” (457 mm)
requried for service
Note: Observe requirements for 39” (914 mm) operating clearance
on either Left or Rear coil opening.
RIGHT:
Min 18” (457 mm)
requried for service
LEFT:
Min 18” (457 mm)
requried for service FRONT:
42” (1067 mm)
C11035
Fig. 4 -- Service Clearance Dimensional Drawing
Step 2 — Complete Pre-Installation Checks
Check Unit Electric Characteristic —
Confirm before installation of unit that voltage, amperage
and circuit protection requirements listed on unit data
plate agree with power supply provided.
Un--crate Unit —
Remove unit packaging except for the top skid assembly,
which should be left in place until after the unit is rigged
into its final location.
Inspect Shipment —
File a claim with shipping company if the shipment is
damaged or incomplete.
Consider System Requirements —
SConsult local building codes and National Electrical
Code (NEC, U.S.A.) for special installation
requirements.
SAllow sufficient space for airflow clearance, wiring,
refrigerant piping, and servicing unit. See Fig. 1 for unit
dimensions and weight distribution data.
SLocate the unit so that the outdoor coil (condenser)
airflow is unrestricted on all sides and above.
SThe unit may be mounted on a level pad directly on the
base channels or mounted on raised pads at support
points. See Tables 1A and 1B for unit operating
weights. See Fig. 1 for weight distribution based on
recommended support points.
NOTE: If vibration isolators are required for a particular
installation, use the data in Fig. 1 to make the proper
selection.
Step 3 — Prepare Unit Mounting Support
Slab Mount —
Provide a level concrete slab that extends a minimum of 6
in. (150 mm) beyond unit cabinet. Install a gravel apron in
front of condenser coil air inlet to prevent grass and
foliage from obstructing airflow.
Step 4 — Rig and Mount the Unit
Rigging —
These units are designed for overhead rigging. Refer to
the rigging label for preferred rigging method. Spreader
bars are not required if top crating is left on the unit. All
panels must be in place when rigging. As further
protection for coil faces, plywood sheets may be placed
against the sides of the unit, behind cables. Run cables to
a central suspension point so that the angle from the
horizontal is not less than 45 degrees. Raise and set the
unit down carefully.
If it is necessary to roll the unit into position, mount the
unit on longitudinal rails, using a minimum of 3 rollers.
Apply force to the rails, not the unit. If the unit is to be
skidded into position, place it on a large pad and drag it
by the pad. Do not apply any force to the unit.
Raise from above to lift the unit from the rails or pad
when unit is in its final position.
After the unit is in position, remove all shipping materials
and top crating.
Step 5 — Complete Refrigerant Piping Connections
Refrigerant lines must be carefully designed and
constructed to ensure equipment reliability and efficiency.
Line length, pressure drop, compressor oil return, and
vertical separation are several of the design criteria that
must be evaluated. See Table 2.
IMPORTANT: Do not bury refrigerant piping
underground.
IMPORTANT: A refrigerant receiver is not
provided with the unit. Do not install a receiver.

506 01 2303 01 9
Specifications are subject to change without notice.
Table 2 – CHS072--121 Piping Recommendations (Single-Circuit Unit)
R-410A Equivalent Length
Ft 0-38 38-75 75-113 113-150
Model
Nominal Capacity
Length Linear
Length Equiiv
0-25
0-38
25-50
38-75
50-75
75-113
75-100
113-115
CHS072 Liquid Line 3/83/83/81/23/81/2
Max Lift
Cool
Heat
25
25
50
50
48
46
75
60
39
31
100
60
Vapor Line 7/87/81-1/81-1/8
Charge (lbs) 17.8 18.8 20.3 22.6 21.4 24.5
CHS091 Liquid Line 1/21/21/21/2
Max Lift
Cool
Heat
25
25
50
50
75
60
100
60
Vapor Line 7/81-1/81-1/81-1/81-1/8
Charge (lbs) 20.9 23.0 24.9 26.8
CHS121 Liquid Line 1/21/21/21/25/8
Max Lift
Cool
Heat
25
25
50
50
75
60
85
60
100
60
Vapor Line 7/81-1/81-1/81-1/81-1/81-3/8
Charge (lbs) 26.8 28.8 30.7 33.4 37.2
Legend:
Length Equiv Equivalent tubing length, including effects of refrigeration specialties devices
Liquid Line Tubing size, inches OD.
Max Lift
Cooling
Heating
Maximum liquid lift at maximum permitted liquid line pressure drop
SIndoor unit ABOVE outdoor unit
SIndoor unit BELOW outdoor unit
Vapor Line Tube size, inches OD
Charge Charge Quantity, lbs. Calculated for both liquid line sizes (where applicable), but only with large
suction line size (where applicable)
NOTE: For applications with linear length greater than 100 ft (30.5 m), contact your local ICP
representative.
Check Vertical Separation —
If there is any vertical separation between the indoor and
outdoor units, check to ensure that the separation is within
allowable limits. Relocate equipment if necessary.
Provide Safety Relief —
If local codes dictate an additional safety relief device,
purchase locally and install locally. Installation will
require the recovery of the factory shipping charge before
the factory tubing can be cut and the supplemental relief
device is installed.
Refrigerant Line Sizing —
Consider the length of the piping required between the
outdoor and indoor units. The maximum allowable line
length is 100 ft (30.5 m). See Table 2. Refrigerant vapor
piping should be insulated.
Risers in Heat Pump Piping Systems —
Elevation differences between the outdoor unit and the
indoor unit in heat pump systems will create two riser line
conditions – one in the liquid line in one mode and one in
the vapor line in the opposite mode. See the following
table to identify which lines are risers in this installation.
Mode
CHS Unit
BELOW
ID Unit
CHS Unit
ABOVE
ID Unit
Riser in Riser in
Cooling Liquid Vapor
(Suction Gas)
Heating Vapor
(Discharge Gas) Liquid
Liquid Line Riser: Refer to Pipe Sizing Table, Table 2;
observe Max Lift limits for liquid line according to unit
mode, equivalent line length and pipe size.
VaporLineRiser:Refer to Table 3 for maximum pipe
size in single pipe vapor risers. All pipe size
recommendations in Pipe Sizing Table, Table 2, satisfy
these maximum vapor line sizes. If this installation is
re--using existing piping, check the vapor line sizes
against these maximum values; replace riser sections with
these pipe sizes if necessary.

10 506 01 2303 01
Specifications are subject to change without notice.
Table 3 – Maximum Vapor Line Sizes
CHS
Size
CHS Unit
BELOW
ID Unit
CHS Unit
ABOVE
ID Unit
Max Diameter, Single Pipe (in.)
072*A/B 1-1/81-5/8
072*G/H 1-1/81-1/8
091*A/B 1-3/81-5/8
121*A/B 1-5/81-5/8
121*G/H 1-3/81-3/8
Table 4 – R--410A-duty Filter Drier(s)
Model-Size Qty Liquid
Line OD
Desiccant
Volume
Part
Number Ref
CHS072 13/8-in 8cu.in. KH43LS088
CHS091 11/2-in 16 cu. in. KH43LS102
CHS121 11/2-in 16 cu. in. KH43LS102
Table 5 – Refrigerant Specialties Part Numbers
LIQUID LINE
SIZE (in.)
LIQUID LINE
SOLENOID VALVE (LLSV)
SOLENOID
COIL
SIGHT
GLASS
FILTER
DRIER
3/8EF680033 plus EF680039 biflow kit EF680037 KM680008
Provided with unit
See Table 4
1/2EF680035 plus EF680039 biflow kit EF680037 KM680004
5/8EF680036 plus EF680039 biflow kit EF680037 KM680005
Install Filter Drier and Moisture Indicator —
Every unit MUST have a bi-directional filter drier in the
liquid line. Locate the filter drier(s) at the indoor unit, close
to the indoor coil’s thermal expansion valve (TXV) inlets.
CHS units include one R--410A-duty filter drier, shipped
in cartons attached to the unit basepan. Remove the filter
drier and prepare to install in the liquid line at the indoor
coil. Do not remove connection fitting plugs until ready to
connect and braze the filter drier into the liquid line
position. See Table 4.
IMPORTANT: A refrigerant receiver is not
provided with the unit. Do not install a receiver.
Installation of liquid line moisture indicating sightglass in
each circuit is recommended. Locate the sightglass(es)
between the outlet of the filter drier and the TXV inlet.
Refer to Table 5 for recommendations on refrigeration
specialties.
Select the filter drier for maximum unit capacity and
minimum pressure drop. Complete the refrigerant piping
from the indoor unit to the outdoor unit before opening
the liquid and vapor service valves at the outdoor unit.
Install Liquid Line Solenoid Valves —
It is recommended that a bi-directional solenoid valve be
placed in the main liquid line (see Figs. 5 & 6) between
the outdoor unit and the indoor coil. Locate the solenoid
valve at the end of the liquid line, near the outdoor unit
connections, with flow direction arrow pointed at the
outdoor unit. Refer to Table 5. (A liquid line solenoid
valve is required when the liquid line length exceeds 75 ft
[23 m].) This valve prevents refrigerant migration (which
causes oil dilution) to the compressor during the off cycle,
at low outdoor ambient temperatures. Wire the solenoid
according to the unit label diagram.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage.
Failure to use a solenoid valve relay (SVR) PNO
HN61PC005 may cause overload of Comfort Alert
Diagnostic Module (CADM) and compressor alarm
lock out.
CAUTION
!
CAPACITY CONTROL LIQUID LINE SOLENOID
VALVE -- CHS units are single--stage only designs. DO
NOT USE a capacity control liquid line solenoid valve on
the indoor coil.
15 DIAMS
MIN 10
DIAMS
8 DIAMS
MIN
INDOOR
COIL CKT
AIRFLOW
TXV
SENSING
BULB
EQUALIZER LINE
SIGHT GLASS
A LOCATION
TXV
FILTER DRIER
A LOCATION
LEGEND
TXV — Thermostatic Expansion Valve
C11036
Fig. 5 -- Location of Sight Glass(es) and Filter Driers
(typical CHS size 072 & 091)