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Page 3

Setting the Unit

CAUTION

In order to avoid injury, take proper precaution when
lifting heavy objects.

CAUTION

Sharp sheet metal edges can cause injury. When
installing the unit, avoid accidental contact with
sharp edges.

Outdoor units operate under a wide range of weather con-
ditions; therefore, several factors must be considered
when positioning the outdoor unit. The unit must be posi-
tioned to give adequate clearances for sufficient airflow
and servicing. A minimum clearance of 24 inches (610 mm)
between multiple units must be maintained. Refer to figure
1 for installation clearances.

36

(914 mm)

Installation Clearances

Figure 1

36*

(914 mm)

*NOTE − A service clearance of 30" (762 mm) must be main-
tained on one of the sides adjacent to the control box. Clear-
ance to one of the other three sides 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).

36*

(914 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).

36

(914 mm)

1 − Place a sound-absorbing material, such as Isomode,

under the unit if it will be installed in a location or posi-
tion that will transmit sound or vibration to the living
area or adjacent buildings.

2 − Install the unit high enough above the ground or roof to

allow adequate drainage of defrost water and prevent
ice buildup.

3 − In heavy snow areas, do not locate the unit where drift-

ing will occur. The unit base should be elevated above
the depth of average snows.

NOTE − Elevation of the unit may be accomplished by
constructing a frame using suitable materials. If a sup-
port frame is constructed, it must not block drain holes
in unit base.

4 − When installed in areas where low ambient tempera-

tures exist, locate unit so winter prevailing winds do not
blow directly into outdoor coil.

5 − Locate unit away from overhanging roof lines which

would allow water or ice to drop on, or in front of, coil or
into unit.

Slab Mounting − Figure 2

When installing a 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 2.
Slab should have a slope tolerance away from the building
of 2 degrees or 2 inches per 5 feet (51 mm per 1524 mm).
This will prevent ice from building up under the unit during a
defrost cycle. Refer to the roof mounting section for barrier
construction if the unit must face prevailing winter winds.

Slab Mounting At Ground Leve

l

discharge air

Mounting slab must slope
away from building.

ground level

structure

Figure 2

Roof Mounting − Figure 3

Install the unit a minimum of 6 inches (152 mm) above the
roof surface to avoid ice build−up around the unit. Locate
the unit above a load bearing wall or area of the roof that
can adequately support the unit. Consult local codes for
rooftop applications.

Summary of Contents for 12HPB Series

Page 1: ...4 532M 06 04 Supersedes 04 04 Table of Contents 12HPB Outdoor Units 1 Shipping Packing List 1 General Information 1 Unit Dimensions 2 Setting the Unit 3 Electrical 4 Refrigerant Piping 6 Refrigerant M...

Page 2: ...tion 4 3 8 111 4 3 8 111 4 3 8 111 4 3 8 111 4 3 8 111 compressor coil drain outlets around perimeter of base optional unit stand off kit 4 field installed B C A optional unit stand off kit 4 field in...

Page 3: ...to allow adequate drainage of defrost water and prevent ice buildup 3 In heavy snow areas do not locate the unit where drift ing will occur The unit base should be elevated above the depth of average...

Page 4: ...G 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...

Page 5: ...power power common common 1st stage aux heat 1st stage aux heat indoor blower compressor Figure 5 R C W1 Y1 O G R C W1 W2 W3 G Outdoor Unit and Blower Unit Thermostat Designations with emergency heat...

Page 6: ...o 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...

Page 7: ...Line IMPORTANT Refrigerant lines must not contact structure Outside Wall Inside Wall Liquid Line Vapor Line IMPORTANT Refrigerant lines must not contact wall Wood Block Between Studs Strap Sleeve Woo...

Page 8: ...ire 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 l...

Page 9: ...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 9 Out...

Page 10: ...d line at the indoor coil Refrigerant Metering Device 12HPB units are used in check expansion valve systems only See the Lennox Engineering Handbook for approved TXV match ups and application informat...

Page 11: ...e wrench 2 Connect gauge to the service port 3 When testing is completed replace service port cap Tighten finger tight then an additional 1 6 turn To Open Service Valve 1 Remove stem cap with an adjus...

Page 12: ...r use oxygen to pressurize a refrigera tion or air conditioning system Oxygen will explode on contact with oil and could cause personal injury WARNING Danger of explosion Can cause equipment damage in...

Page 13: ...r port hose from vacuum pump Attach the manifold center port hose to a nitrogen cylin der with pressure regulator set to 150 psig 1034 kPa and purge the hose Open the manifold gauge valves to break th...

Page 14: ...which charg ing method to use Proceed with the appropriate charg ing procedure Weighing in the Charge TXV Systems Outdoor Temp 65 F 18 C If the system is void of refrigerant or if the outdoor ambient...

Page 15: ...erature to check liquid line tempera ture Verify the unit charge using the approach method 5 The difference between the ambient and liquid temper atures should match values given in table 6 If the val...

Page 16: ...ts An amber indicating light simultaneously comes on to remind the homeowner that he is operating in the emergency heat mode Emergency heat is usually used during an outdoor shut down but it should al...

Page 17: ...mode If the jumper is removed before an addi tional 5 second period has elapsed 7 seconds total the unit will remain in defrost mode until the defrost thermostat opens or 14 minutes have passed If th...

Page 18: ...lubrication is needed 3 Adjust blower speed for cooling Measure the pressure drop over the coil to determine the correct blower CFM Refer to the unit information service manual for pressure drop tabl...

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