Refrigeration - Geostar ASTON SERIES Installation Manual

ASTON INDOOR SPLIT SERIES INSTALLATION MANUAL

Refrigeration

The indoor split series comes with a holding charge. The charge
must be adjusted in the field based on performance. Refrigeration
piping on the split consists of installing a brazed copper line
set between the blower coil unit and the unit's split compressor
section. To select the proper tube diameters for the installation,
refer to the Line Set Sizes table. Line sets over 60 feet long are not
recommended because of oil return and pressure drop problems.
The suction line must always be insulated. Handle and route the
line sets carefully to avoid kinking or bending the tubes. If the line
set is kinked or distorted and it cannot be formed back into its
original shape, the bad portion of the pipe should be replaced. A
restricted line set will affect the performance of the system.
Fasten the copper line set to the blower coil unit as instructed
by the coil installation instructions shown in Figure 14. Nitrogen
should be bled through the system at 2 to 3 PSI to prevent
oxidation inside the refrigerant tubing. Use a low silver phos-
copper braze alloy on all brazed connections.
Figure 13: Typical Split System Refrigerant Line Connections
Service ports for
attaching refrigerant
gauges
Replace caps after
opening system
ccw
Position
CW - Full In
CCW - Full Out 1/2 turn CW
CCW - Full Out
Insulated
Suction Line
ccw
Braze
Connection
Liquid
Line
Description System
Shipping Position Closed
Service Position Open
Operation Position Open
The indoor split service valves are recessed in the unit's corner post
and protected by a cover. Remove the protective cover and braze
the line set to the service valve stubs as shown in Figure 13. Care
should be used when brazing the service valves as to not scorch the
paint. Nitrogen should be bled through the system at 2 to 3 psi to
prevent oxidation contamination. Use a low silver phos-copper braze
alloy on all brazed connections. Indoor split units are shipped with a
factory charge and service valves are not to be opened until the line
set has been leak tested, purged, and evacuated. Schrader cores
should be removed before brazing, and replaced after the valves
have cooled. A heat sink should be used on the service valve and
TXV to prevent damage caused by excessive heat. When brazing is
completed, reinstall the protective cover.
Figure 14: Attaching the Air Coil
TXV ("IN" toward condensing unit)
TXV has internal check valve
Service
Port
Open
Open
Closed
28
Equalizer Bulb
Suction
Liquid