Leak Testing - Lennox Merit 10HPB Series Installation Instructions Manual

The ball valve is equipped with a service port with a factory−
installed Schrader valve. A service port cap protects the
Schrader valve from contamination and assures a leak−
free seal.
Service Valve
(Valve Closed)
service
port
to outdoor coil
service
port cap
Schrader valve open
to line set when valve is
closed (front seated)
Service Valve
(Valve Open)
insert hex
wrench here
service
port
to outdoor coil
service port
cap
Schrader
valve
Figure 13
Vapor Line (Ball Type) Service Valve
(Valve Open)
To open: rotate stem counter-clockwise 90_.
To close: use adjustable wrench and
rotate stem clockwise 90_.
service port
Schrader
valve
service
port
ball
field side
(shown open)
Figure 14
stem cap
insert hex
wrench here
to indoor coil
(valve front seated)
stem cap
to indoor coil
cap
unit side
stem
stem cap
Page 12

Leak Testing

After the line set has been connected to the indoor and
outdoor units, check the line set connections and indoor
unit for leaks.
WARNING
Danger of fire. Bleeding the refrigerant
charge from only the high side may re-
sult in the low side shell and suction
tubing being pressurized. Appplication
of a brazing torch while pressurized
may result in ignition of the refrigerant
and oil mixture − check the high and low
pressures before unbrazing.
WARNING
Refrigerant can be harmful if it is inhaled. Refrigerant
must be used and recovered responsibly.
Failure to follow this warning may result in personal
injury or death.
WARNING
Danger of explosion: Can cause equip-
ment damage, injury or death. Never
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,
injury or death. When using a high pressure gas
such as dry nitrogen to pressurize a refrigeration or
air conditioning system, use a regulator that can
control the pressure down to 1 or 2 psig (6.9 to 13.8
kPa).
Using an Electronic Leak Detector or Halide
1 − Connect a cylinder of HCFC-22 to the center port of the
manifold gauge set.
2 − With both manifold valves closed, open the valve on
the HCFC-22 cylinder (vapor only).
3 − Open the high pressure side of the manifold to allow
the HCFC-22 into the line set and indoor unit. Weigh in
a trace amount of HCFC-22. [A trace amount is a maxi-
mum of 2 ounces (57 g) or 3 pounds (31 kPa) pres-
sure.] Close the valve on the HCFC-22 cylinder and the
valve on the high pressure side of the manifold gauge
set. Disconnect the HCFC-22 cylinder.
4 − Connect a cylinder of nitrogen with a pressure regulat-
ing valve to the center port of the manifold gauge set.