Lennox HS27-024 User manual

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504,669M
*P504669M*
02/04
*2P0204*
2000 Lennox Industries Inc.
Dallas, Texas, USA

HS27 Outdoor Unit
HS27 outdoor units are designed for expansion valve sys-
tems only. They are not designed for RFC systems. Refer to
Lennox engineering handbook for expansion valve kits
which must be ordered separately.
Shipping & Packing List
1 − Assembled HS27 outdoor unit
2 − Grommets (for liquid and vapor lines)
1 − Bushing (for low voltage wiring)
Check equipment for shipping damage. If you find any
damage, immediately contact the last carrier.
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, person-
al injury or loss of life. Installation and service must
be performed by a qualified installer or service
agency.
IMPORTANT
The Clean Air Act of 1990 bans the intentional vent-
ing of refrigerant (CFC’s and HCFC’s) as of July 1,
1992. Approved methods of recovery, recycling or
reclaiming must be followed. Fines and/or incarcera-
tion may be levied for noncompliance.
INSTALLATION
INSTRUCTIONS
HS27 SERIES UNITS
CONDENSING UNITS
504,669M
02/04
Supersedes 12/02
Table of Contents
HS27 Outdoor Unit 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shipping & Packing List 1. . . . . . . . . . . . . . . . . . . . . . . . .
General Information 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unit Dimensions 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Arrangement 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting the Unit 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Refrigerant Piping 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Refrigerant Metering Device 9. . . . . . . . . . . . . . . . . . . . .
Manifold Gauge Set 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Valves 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Leak Testing 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Evacuation 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Start−Up 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Charging 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
System Operation 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Accessories 14. . . . . . . . . . . . . . . . . . . . . . . . . .
Start−up & Performance Check List 15. . . . . . . . . . . . . . .
RETAIN THESE INSTRUCTIONS
FOR FUTURE REFERENCE
General Information
These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.
WARNING
This product and/or the indoor unit it is matched with
may contain fiberglass wool.
Disturbing the insulation during installation, mainte-
nance, or repair will expose you to fiberglass wool
dust. Breathing this may cause lung cancer. (Fiber-
glass wool is known to the State of California to
cause cancer.)
Fiberglass wool may also cause respiratory, skin,
and eye irritation.
To reduce exposure to this substance or for further
information, consult material safety data sheets
available from address shown below, or contact your
supervisor.
Lennox Industries Inc.
P.O. Box 799900
Dallas, TX 75379−9900
Litho U.S.A.

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Unit Dimensions − inches (mm)
electrical
inlets
vapor line
inlet
liquid
line inlet
DISCHARGE AIR
inlet
air
COMPRESSOR
B
Top View
Side ViewAccess View
4-1/2 (114)
2-3/4 (70) 4
(102)
6-1/16
(154)
1-3/8
(35)
A
4-7/8 (22) 4
(102)
2-9/16
(65)
18-5/8
(473)
26-5/8 (676)
34-1/16 (865)
2
(51)
28-1/8 (714)
7-1/2
(191) 7-1/2
(191)
3-7/8
(98)
3-7/8
(98)
airinlet
airinlet
2
(51)
32-1/8 (816)
Model No. A B
HS27-024 in. 30-7/8 12-3/4
HS27-024
HS27-030 mm 784 324
HS27-036 in. 40-7/8 19-3/4
HS27-036
HS27-042 mm 1038 502

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Parts Arrangement
Figure 1
outdoor fan
(not shown)
top of cabinet
contactor
run capacitor
terminal box
liquid line
service valve
and gauge port
vapor valve
and gauge port
compressor
low pressure
switch
high pressure
switch
ground lug
Setting the Unit
CAUTION
In order to avoid injury, take proper precaution when
lifting heavy objects.
CAUTION
Danger of sharp metallic edges. Can cause injury.
Take care when servicing unit to avoid accidental
contact with sharp edges.
Refer to unit dimensions for sizing mounting slab, platform-
s, or supports. Refer to figure 2 for installation clearances.
36"
(914 mm)
36"
(914 mm)
*36"
(914 mm)
*36"
(914 mm)
Installation Clearances
Figure 2
NOTE − A service access
clearance of 30" (762 mm)
must be maintained in front
of the service access panel.
Clearance to one side must
be 36" (914 mm). Clearance
to one of the remaining two
sides may be 12" (304 mm)
and the final side may be 6"
(152 mm).
NOTE − A clearance of 24" (610 mm)
must be maintained between two units.
NOTE − 48" (1219 mm) clearance required on top
of unit. Maximum soffit overhang is 36" (914 mm).

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A − Slab Mounting
When you install the unit at grade level, the top of the slab
should be high enough above the grade so that water from
higher ground will not collect around the unit. See figure 3.
Slab should have a slope tolerance away from the building
of 2 degrees or 2 inches per 5 feet (51 mm per 1.5 m).
2 degrees or
2 in. per 5 foot
(51 mm per 1.5 m)
slope tolerance away
from building structure
Slab Mounting
ground level
mounting
slab
building
structure
discharge air
Figure 3
B − Roof Mounting
Install unit at a minimum of 4 inches above surface of the roof.
Care must be taken to ensure weight of unit is properly distrib-
uted over roof joists and rafters. Either redwood or steel sup-
ports are recommended.
Electrical
In the U.S.A., wiring must conform with current local codes
and the current National Electric Code (NEC). In Canada,
wiring must conform with current local codes and the current
Canadian Electrical Code (CEC).
Refer to the furnace or blower coil installation instructions
for additional wiring application diagrams and refer to unit
nameplate for minimum circuit ampacity and maximum
overcurrent protection size.
WARNING
Unit must be grounded in accordance with
national and local codes.
Electric Shock Hazard.
Can cause injury or death.
1. Install line voltage power supply to unit from a properly
sized disconnect switch.
2. Ground unit at unit disconnect switch or to an earth
ground.
NOTE − To facilitate conduit, a hole is in the bottom of
the control box. Connect conduit to the control box us
ing a proper conduit fitting.
NOTE − Units are approved for use only with copper
conductors.
24V, Class II circuit connections are made in the low
voltage junction box. Refer to figure 4 for field wiring
diagram.
NOTE − A complete unit wiring diagram is located in
side the unit control box cover.
3. Install room thermostat (ordered separately) on an in-
side wall approximately in the center of the conditioned
area and 5 feet (1.5 m) from the floor. It should not be
installed on an outside wall or where it can be effected
by sunlight, drafts or vibrations.
4. Install low voltage wiring from outdoor to indoor unit
and from thermostat to indoor unit. See figure 5.

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Outdoor Unit
Field Wiring Diagram
YELLOW
(LEADLESS)
Figure 4
Thermostat Designations
R
W1
Y
G
C
R
W
Y
G
C
Thermostat Furnace
Outdoor Unit
Y1 Outdoor Unit
C Outdoor Unit
power
heat
cooling
indoor blower
common
NOTE − see unit wiring diagram for
power supply connections.
NOTE − If the indoor unit is not equipped with blower relay, it must be field−provided and installed (P−8−3251 or equivalent).
Figure 5

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Refrigerant Piping
Field refrigerant piping consists of liquid and vapor lines
from the outdoor unit (sweat connections) to the indoor coil
(flare or sweat connections). Use Lennox L15 (sweat, non-
flare) series line sets as shown in table 1 or use field-fabri-
cated refrigerant lines. Refer to Refrigerant Piping Guide
(Corp. 9351−L9) for proper size, type, and application of
field−fabricated lines. Valve sizes are also listed in table 1.
Table 1
Refrigerant Line Sets
HS27
Field Valve Size
Connections Recommended Line Set
HS27 Liquid
Line
Vapor
Line Liquid
Line
Vapor
Line
L15
Line Sets
−024
−030
3/8 in
(10 mm)
3/4 in.
(19 mm)
3/8 in
(10 mm)
3/4 in.
(19 mm)
L15−41
15 ft. − 50 ft.
(4.6 m − 15 m)
−036
−042
3/8 in
(10 mm)
7/8 in.
(22 mm)
3/8 in
(10 mm)
7/8 in.
(22 mm)
L15−65
15 ft. − 50 ft.
(4.6 m − 15 m)
NOTE − Units are designed for line sets of up to 50 feet (15
m). For applications longer than 50 feet, consult the Len-
nox Refrigerant Piping Guide (Corp. 9351−L9).Select line
set diameters from table 1 to ensure that oil returns to the
compressor.
Installing Refrigerant Line
During the installation of any heat pump or a/c system, it is
important to properly isolate the refrigerant lines to prevent
unnecessary vibration. Line set contact with the structure
(wall, ceiling or floor) causes some objectionable noise
when vibration is translated into sound. As a result, more
energy or vibration can be expected. Closer attention to
line set isolation must be observed.
Following are some points to consider when placing and
installing a high−efficiency outdoor unit:
1- Placement −Be aware some localities are adopting
sound ordinances based on how noisy the unit is from
the adjacent property not at the original installation.
Install the unit as far as possible from the property line.
When possible, do not install the unit directly outside a
window. Glass has a very high level of sound transmis-
sion.
2- Line Set Isolation − The following illustrations demon-
strate procedures which ensure proper refrigerant line
set isolation. Figure 6 shows how to install line sets on
vertical runs. Figure 7 shows how to install line sets on
horizontal runs. Figure 8 shows how to make a transition
from horizontal to vertical. Finally, figure 9 shows how to
place the outdoor unit and line set.

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Refrigerant Line Sets
How To Install Vertical Runs
(new construction shown)
PVC Pipe Fiberglass
Insulation
Caulk
Outside Wall
Vapor Line
(wrapped with Armaflex)
Liquid Line
IMPORTANT - Refrigerant
lines must not contact
structure.
Outside Wall
Inside Wall
Liquid LineVapor Line
IMPORTANT - Refrigerant
lines must not contact wall.
Wood Block
Between Studs
Strap
Sleeve
Wood Block
Strap
Sleeve
Wire Tie
Wire Tie
Wire Tie
NOTE - Similar installation practices should be used if
line set is to be installed on exterior of outside wall.
Figure 6

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Refrigerant Line Sets:
Installing Horizontal Runs
8 feet
8 feet
Metal Sleeve
Strapping Material (around vapor line only)
Tape or Wire Tie
Wire Tie
(around vapor line only)
Floor Joist or
Roof Rafter
Tape or Wire Tie
Strap the vapor line to the joist or rafter at 8 ft.
intervals then strap the liquid line to the vapor line.
To hang line set from joist or rafter,
use either metal strapping material
or anchored heavy nylon wire ties.
Floor Joist or Roof Rafter
Figure 7

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Refrigerant Line Sets:
Transition From Vertical To Horizontal
Liquid Line
Vapor Line
Wrapped in
Armaflex
Strap Liquid Line
To Vapor Line
Metal
Sleeve
Anchored Heavy
Nylon Wire Tie
Automotive
Muffler-Type
Hanger
Wall
Stud
Wall
Stud
Liquid Line
Vapor Line
Wrapped in
Armaflex
Strap Liquid Line
To Vapor Line
Metal
Sleeve
Figure 8
Outside Unit Placement and Installation
Install unit away from windows.
Two 90° elbows
installed in line set
will reduce line set
vibration.
Figure 9

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Brazing Connection Procedure
1 − Cut ends of the refrigerant lines square (free from nicks
or dents). Debur the ends. The pipe must remain
round, do not pinch end of the line.
2 − Before making line set connections, use dry nitrogen to
purge the refrigerant piping. This will help to prevent
oxidation and the introduction of moisture into the sys-
tem.
3 − Use silver alloy brazing rods (5 or 6 percent minimum
silver alloy for copper−to−copper brazing or 45 percent
silver alloy for copper−to−brass or copper−to−steel braz-
ing) which are rated for use with HCFC−22 refrigerant.
Wrap a wet cloth around the valve body and the copper
tube stub. Braze the line set to the service valve.
4 − Wrap a wet cloth around the valve body and copper
tube stub to protect it from heat damage during braz-
ing. Wrap another wet cloth underneath the valve body
to protect the base paint.
NOTE − The tube end must stay bottomed in the fitting
during final assembly to ensure proper seating, sealing
and rigidity.
5 − Install a field−provided thermal expansion valve (ap-
proved for use with HCFC−22 refrigerant) in the liquid
line at the indoor coil.
Refrigerant Metering Device
H27 units are used in expansion valve systems only. See
the Lennox Engineering Handbook for approved TXV
match-ups and application information.
Expansion valves equipped with Chatleff fittings are avail-
able from Lennox. Refer to the Engineering Handbook for
applicable expansion valves for use with specific match-
ups.
If you install an expansion valve with an indoor coil that
includes a fixed orifice, remove the orifice before instal-
ling the expansion valve.
IMPORTANT
Failure to remove RFC orifice when installing an ex-
pansion valve on the indoor coil will result in improp-
er operation and damage to the system.
See figure 10 for installation of the check expansion valve.
Metering Device Installation
expansion
valve
o−ring
o−ring
strainer
liquid line
stub
distributor
Figure 10
Manifold Gauge Set
When checking the unit charge, use a manifold gauge set
that is equipped with low loss" hoses. Do not use a man-
ifold gauge set with anything other than a low loss" hose.
Service Valves
The liquid line and vapor line service valves (figures 11 and
12) and gauge ports are used for leak testing, evacuating,
charging and checking charge. See table 2 for torque re-
quirements.
Each valve is equipped with a service port which has a fac-
tory−installed Schrader valve. A service port cap protects
the Schrader valve from contamination and serves as the
primary leak seal.
Table 2
Torque Requirements
Part Recommended Torque
Service valve cap 8 ft.− lb. 11 NM
Sheet metal screws 16 in.− lb. 2 NM
Machine screws #10 28 in.− lb. 3 NM
Compressor bolts 90 in.− lb. 10 NM
Gauge port seal cap 8 ft.− lb. 11 NM
To Access Schrader Port:
1 − Remove the service port cap with an adjustable wrench.
2 − Connect gauge to the service port.
3 − When testing is complete, replace the service port cap.
Tighten finger tight, then an additional 1/6 turn.
To Open Service Valve:
1 − Remove stem cap with an adjustable wrench.
2 − Use a service wrench with a hex−head extension to
back the stem out counterclockwise as far as it will go.