Brazing Connections - Lennox Merit Series13ACD Installation Instructions Manual

1
CUT AND DEBUR
7
INSTALL CORE ONLY FOR
BOTH SERVICE PORTS AFTER
THEY HAVE COOLED.

Brazing Connections

Use the following procedure to braze the line set to the new
outdoor unit. Figure 13 is provided as a general guide for
preparing to braze the line set to the outdoor unit.
WARNING
Danger
refrigerant charge from only the high
side may result in the low side shell
and
pressurized. Application 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
When using a high pressure gas such
as dry nitrogen to pressurize a
refrigeration
system, use a regulator that can
control the pressure down to 1 or 2
psig (6.9 to 13.8 kPa).
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. Remove service cap and core from both the suction
and liquid line service ports.
505366M 01/08
2
REMOVE CAP AND CORE FROM
BOTH LIQUID AND SUCTION
SERVICE PORTS
SUCTION LINE
INDOOR UNIT
LIQUID LINE
6
BRAZE LINE SET
Figure 13. Brazing Connections
of fire. Bleeding
suction tubing
or air conditioning
3
ATTACH
GAUGES
SERVICE PORT MUST BE
OPEN TO ALLOW EXIT
SERVICE
POINT FOR NITROGEN
VALVE
SERVICE
VALVE
5
3. Connect gauge low pressure side to liquid line service
valve.
4. To protect components during brazing, wrap a wet
cloth around the liquid line service valve body and
copper tube stub and use another wet cloth
underneath the valve body to protect the base paint.
5. Flow regulated nitrogen (at 1 to 2 psig) through the
refrigeration gauge set into the valve stem port
the
connection on the liquid line service valve and out of
the valve stem port connection on the suction service
valve. The TXV metering device at the indoor unit coil
being
will allow low pressure nitrogen to flow through the
system.)
NOTE − The fixed orifice or TXV metering device at the
indoor unit will allow low pressure nitrogen to flow through
the system.)
NOTE − Use silver alloy brazing rods with five or six percent
minimum silver alloy for copper−to−copper brazing or 45
percent silver alloy for copper−to−brass or copper−to−steel
brazing.
6. Braze the line to the liquid line service valve. Turn off
nitrogen flow.
Repeat procedure starting at paragraph 4 for brazing the
suction line to service port valve.
7. 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.
Page 8
OUTDOOR
UNIT
4
FLOW NITROGEN
WRAP
NITROGEN
SERVICE
VALVE
IMPORTANT