Lennox 14HPX Unit Information page 15

A − Plumbing
Field refrigerant piping consists of liquid and vapor lines
from the outdoor unit (sweat connections). Use Lennox
L15 (sweat) series line sets as shown in table 4.
TABLE 4
Refrigerant Line Sets
Field
Model
Connections
−018
3/8 in. 3/4 in
−024
(10 mm) (19 mm)
−030
−036
3/8 in. 7/8 in
−042
(10 mm) (22 mm)
−048
3/8 in. 1−1/8 in.
−060
(10 mm) (29 mm)
B − Service Valves
IMPORTANT
Only use Allen wrenches of sufficient hardness
(50Rc − Rockwell Harness Scale min). Fully in-
sert the wrench into the valve stem recess.
Service valve stems are factory torqued (from 9
ft lbs for small valves, to 25 ft lbs for large
valves) to prevent refrigerant loss during ship-
ping and handling. Using an Allen wrench rated
at less than 50Rc risks rounding or breaking off
the wrench, or stripping the valve stem recess.
The liquid and vapor line service valves (figures 16 and 17)
and gauge ports are accessible from outside the unit.
Each valve is equipped with a service port. The service ports
are used for leak testing, evacuating, charging and checking
charge. A schrader valve is factory installed. A service port cap
is supplied to protect the schrader valve from contamination
and serve as the primary leak seal.
NOTE-Always keep valve stem caps clean.
To Access Schrader Port:
1 − Remove service port cap with an adjustable 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 Liquid or Vapor Line Service Valve:
1 − Remove stem cap with an adjustable wrench.
2 − Using service wrench and hex head extension (5/16 for
vapor line and 3/16 for liquid line), back the stem out coun-
terclockwise until the valve stem just touches the retaining
ring.
3 − Replace stem cap and tighten finger tight, then tighten an
additional 1/6 turn.
Recommended Line Set
3/8 in. L15−41
3/4 in
(10 15 ft. − 50 ft.
(19 mm)
mm) (4.6 m − 15 m)
3/8 in. L15−65
7/8 in
(10 15 ft. − 50 ft.
(22 mm)
mm) (4.6 m − 15 m)
3/8 in.
1−1/8 in. Field
(10
(29 mm) Fabricated
mm)
Do not attempt to backseat this valve. Attempts to
backseat this valve will cause snap ring to explode
from valve body under pressure of refrigerant.
Personal injury and unit damage will result.
To Close Liquid or Vapor Line Service Valve:
1 − Remove stem cap with an adjustable wrench.
2 − Using service wrench and hex head extension (5/16 for
vapor line and 3/16 for liquid line), turn stem clockwise to
seat the valve. Tighten firmly.
3 − Replace stem cap. Tighten finger tight, then tighten an
additional 1/6 turn.
LIQUID LINE SERVICE VALVE (VALVE OPEN)
INSERT HEX
WRENCH HERE
SERVICE
PORT
TO COMPRESSOR
SERVICE
PORT
CAP
SCHRADER
VALVE
LIQUID LINE SERVICE VALVE (VALVE CLOSED)
SERVICE
PORT
TO
COMPRESSOR
SERVICE
PORT
CAP
SCHRADER VALVE OPEN
TO LINE SET WHEN VALVE IS
CLOSED (FRONT SEATED)
Page 15
DANGER
STEM CAP
TO INDOOR COIL
RETAINING RING
STEM CAP
INSERT HEX
WRENCH HERE
TO INDOOR COIL
VALVE FRONT
SEATED
FIGURE 16