International comfort products N4H3: C4H3 Installation Instructions Manual page 8

INSTALLATION INSTRUCTIONS
F. SERVICE VALVES
Service valves are closed and plugged from the factory.
Outdoor units are shipped with a refrigerant charge
sealed in the unit. Leave the service valves closed until all
other refrigerant system work is complete or the charge
will be lost. Leave the plugs in place until line set tubing is
ready to be inserted.
Heat pumps require a piston metering device in the liquid
service valve for proper heating operation. Piston is
shipped in the piston body of the liquid service valve,
temporarily held in place with a plastic cap. Do not remove
the plastic cap until line set tubing is ready to be installed.
Refer to Figure 7 and follow these steps for piston
installation:
1. Remove plastic cap holding piston in piston body of
liquid service valve.
2. Check that piston size (stamped on side of piston)
matches with number listed on unit rating plate.
Return piston to piston body of liquid service valve
(either direction).
3. Find plastic bag taped to unit containing copper
adapter tube, brass nut, and plastic washer.
4. Install plastic washer in the seat inside piston body.
5. Fit brass nut onto adapter tube and install tube
onto liquid service valve. Tighten nut finger tight,
then wrench additional ½ turn only. Over tightening
may damage the plastic washer.
Service valve bodies are brass and suction tube stub is
copper.
Liquid Service Valve with Heating
Figure 7
Piston and Adapter Tube
BRASS NUT
ADAPTER TUBE
PISTON
PISTON BODY
LIQUID SERVICE VALVE
Vapor Service Valve
VALVE CORE
8
PLASTIC WASHER
SERVICE VALVE
R−410A Split System Heat Pump
G. BRAZING CONNECTIONS
NOTE:
For Liquid Service Valve − Braze lineset to adapter tube
BEFORE bolting adapter to valve. This helps prevent
overheating and damage to plastic washer or o−ring.
For Vapor Service Valve − remove valve core from
schrader port on Service Valve BEFORE brazing. This
helps prevent overheating and damage to valve seals
(refer to Figure 7). Replace valve core when brazing is
completed.
WARNING
!
FIRE HAZARD
Failure to remove refrigerant and oil charge before
brazing could result in personal injury, death, and/
or property damage.
Refrigerant and oil mixture could ignite and burn
as it escapes and contacts brazing torch. Make
sure the refrigerant charge is properly removed
from both the high and low sides of the system be-
fore brazing any component or lines.
Clean line set tube ends with emery cloth or steel brush.
Remove any grit or debris.
Insert line set tube ends into service valve tube stubs.
Apply heat absorbing paste or heat sink product between
service valve and joint. Wrap service valves with a heat
sinking material such as a wet cloth.
Braze joints using a Sil−Fos or Phos−copper alloy.
CAUTION
!
PRODUCT DAMAGE HAZARD
Failure to follow this caution may result in product
damage.
Braze with Sil−Fos or Phos−copper alloy on cop-
per−to−copper joints and wrap a wet cloth around
rear of fitting to prevent damage to TXV.
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