Sharp AF-S100RX, Service Manual

Page: 40 / 62

Section 5 Sealed System
5 -14
Follow the numbered sequence for all products:
1. Disconnect electrical supply to unit.
2. Remove all components necessary to access the
compressor assembly in the unit.
3. Attach an approved self tapping line tap valve to the
process tube. Connect refrigerant recovery system
to tap valve. Turn on recovery system, open the
line tap valve, and allow refrigerant to flow into an
approved tank.
4. Remove leads from compressor motor terminals.
5. Remove mounting nuts and washers.
6. After refrigerant is completely recovered, cut suction
and discharge lines as close to compressor as
possible. Leave only enough tubing to pinch off and
seal defective compressor. Plug or tape any open
system tubing to avoid entrance of moisture and air
into system. Remove inoperable compressor and
transfer mounting parts to new compressor.
7. Release holding charge (release slowly to avoid oil
discharge) on new compressor to ensure there is
no leak in seam or tubing. Reinstall rubber plug.
8. Install new compressor in exact same manner as
original compressor.
9. Reform both suction and discharge lines to align with
new compressor. If they are too short, use
additional lengths of tubing. Joints should overlap
Clean and mark area where tubing should be cut.
Cut tubing with tubing cutter. Work quickly to avoid
letting moisture and air into system.
10. Solder all connections according to soldering
procedure.
DO NOT OPERATE RECIPROCATING
COMPRESSORS WHEN CHARGING LIQUID
REFRIGERANT INTO SYSTEM THROUGH ITS
PROCESS TUBE.
ÒÑÌÛ
If low-side process tube is too short, silver solder four
inch piece of tubing onto process tube at this time.
On R-410A systems, compressor must NOT
be left open to atmosphere for more than 10
minutes to prevent moisture contamination of
oil.
Installing a New Compressor
Manufacturers have redesigned their compressors with
increased wall thickness due to the higher pressure
associated with R-410A. The internal pressure relief
for R-410A will open at 550-625 psi. Suction and
discharged pressure are 40% to 70% greater than R-22
and the discharge temperature of R-410A is lower due to
its higher vapor heat capacity.
Replacement of the compressor must be done in a
continuous sequence so the system is exposed to the
atmosphere no longer than necessary.
All replacement compressors are shipped with rubber
plugs in the suction and discharge tubes and contain the
correct oil charge and a holding charge of inert gas.
Before installing the replacement compressor, remove
the discharge plug and check for the pop sound of the
inert gas leaving the compressor.
If the compressor checks OK, reinstall the plug. Do not
remove any of the plugs again until the compressor is in
position and you are ready to braze the lines.
A new compressor which is cold (e.g. after having been
kept in a cold service van) should be left to warm to
the surrounding temperature before the plugs on the
compressor connections are removed. This will help
prevent condensation from forming in the oil and the
compressor. Also, avoid opening the system when any
of the components or lines are cold.
A process tube is connected onto the high-side process
tube where the line splits into capillary tubes. The other
process tube is connected to the tubing prior to entering
the accumulator.
ÝßËÌ×ÑÒ
Entirely new compressors have been developed
for use with R-410A refrigeration systems.
Both compressor and electric motor have been
modified. Old compressors intended for R-22
refrigerant must not be used for new systems
charged with R-410A.
DO NOT use compressor if you do not hear this
sound.