Brazing Connections - Lennox Merit Series13HPD Units Installation Instructions Manual

NOTE − The CTXV can be installed internally in coil
blowers, or external or internal to indoor coil only
applications.
Table 4. CTXV Indoor Kits
Model
13HPD−018, −024, −030, −036
13HPD−042, −048
13HPD−060
IMPORTANT
Failure to remove a fixed orifice when installing an
expansion valve on the indoor coil will result in
improper operation and damage to the system.

Brazing Connections

WARNING
Polyol ester (POE) oils used with HFC−410A
refrigerant absorb moisture very quickly. It is very
important that the refrigerant system be kept
closed as much as possible. DO NOT remove line
set caps or service valve stub caps until you are
ready to make connections.
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).
Use the following procedure to braze the line set to the new
outdoor unit. Figure 17 is provided as a general guide for
preparing to braze the line set to the outdoor unit.
Before brazing the line set, remove the service port core
from both of the outdoor unit's service valves as illustrated
in figure 16.
Kit Number
LB−85759F
LB−85759G
100188−01
or air conditioning
OUTDOOR UNIT
SERVICE VALVE
Figure 16. Typical Service Valve Port Core Removal
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.
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 vapor and
liquid line service ports.
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
connection on the liquid line service valve and out of
the valve stem port connection on the vapor service
valve. The CTXV metering device at the indoor unit
coil will allow low pressure nitrogen to flow through the
system.)
NOTE − The TXV metering device at the indoor unit coil 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.
Page 9
REMOVE SERVICE
PORT CAP
REMOVE PORT CORE
WARNING
of fire. Bleeding
suction tubing
the
being
13HPD SERIES