Testing For Leaks - Lennox Merit Series13HPD Units Installation Instructions Manual

1
CUT AND DEBUR
INDOOR UNIT COIL
6
BRAZE LINE SET
6. Braze the line to the liquid line service valve. Turn off
nitrogen flow. Repeat procedure starting with
paragraph 4 for brazing the vapor line to vapor service
valve.
After all connections have been brazed, disconnect
manifold gauge set the from service ports and remove
wrapping. Reinstall the service port core for both of the
outdoor unit's service valves as illustrated in figure 18.
OUTDOOR UNIT
LIQUID AND VAPOR
SERVICE VALVES
Figure 18. Typical Service Valve Port Core
Installation

Testing for Leaks

After the line set has been connected to both the indoor
and outdoor units, check the line set connections at both
the indoor and outdoor units unit for leaks. Use the
following procedure to test for leaks:
IMPORTANT
Leak detector must be capable of sensing HFC
refrigerant.
1. Connect an HCFC−22 manifold gauge set high
pressure hose to the vapor valve service port.
505361M 09/07
2
REMOVE CAP AND CORE FROM
BOTH SERVICE PORTS
VAPOR LINE
LIQUID LINE
5
Figure 17. Brazing Connections
DO NOT INSTALL
CAPS AT THIS TIME
INSTALL SERVICE
PORT CORES
3
ATTACH
GAUGES
SERVICE
VALVE
SERVICE
VALVE
FLOW NITROGEN
NITROGEN
NOTE − Normally, the high pressure hose is connected to
the liquid line port; however, connecting it to the vapor port
better protects the manifold gauge set from high pressure
damage.
Refrigerant can be harmful if it is inhaled.
Refrigerant must
responsibly.
Failure to follow this warning may result in personal
injury or death.
Fire, Explosion and Personal Safety
Hazard.
Failure to follow this warning could
result in damage, personal injury or
death.
Never use oxygen to pressurize or
purge refrigeration lines. Oxygen,
when exposed to a spark or open
flame, can cause damage by fire and/
or an explosion, that could result in
personal injury or death.
2. With both manifold valves closed, connect the cylinder
of HCFC−22 refrigerant to the center port of the
manifold gauge set. Open the valve on the HCFC−22
cylinder (vapor only).
3. Open the high pressure side of the manifold to allow
HCFC−22 into the line set and indoor unit.
4. Weigh in a trace amount of HCFC−22. [A trace amount
is a maximum of two ounces (57 g) refrigerant or three
pounds (31 kPa) pressure].
Page 10
13HPD
UNIT
4
WRAP SERVICE
VALVE
WARNING
be used and
WARNING
recovered