Sharp AF-S100RX, Service Manual

Page: 34 / 62

Section 5 Sealed System
5 -8
If dry nitrogen or carbon dioxide is not available.
Follow instructions 1 through 3, then use 4 and 5 listed
below as an alternative method.
4. Connect gauges to charging hose fittings. Pull a
vacuum on each side of the system.
5. Leave the vacuum on each side of the system for 24
hours. Any loss of vacuum is an indication of a leak.
Compressor Oil Contamination
Before installing new compressor, check for possible
system contamination by obtaining an oil sample from
the old compressor. On R-410A systems use an oil test
kit to check for contamination. If oil has a burned odor
or shows contamination (dark color), the system should
be flushed to remove as much of the contamination as
possible before installing a new compressor. If this
contamination is allowed to remain in the system it will
mix with the new oil causing it to become contaminated
and damage the new compressor or cause a restriction
in the cap tube.
Flushing The System With Nitrogen
It is recommended that system be flushed with dry
Nitrogen. However, if refrigerant is used to flush the
system you must look at the serial plate to see what
type of refrigerant is used in the system. This is the only
refrigerant that can be used to flush the system and it
must be recovered.
NEVER PRESSURIZE WITH OXYGEN. NEVER
OPEN A HIGH PRESSURE TANK UNLESS IT IS
EQUIPPED WITH A PRESSURE REGULATOR.
NEVER PUT HIGH PRESSURE ON THE DOME OF
THE COMPRESSOR - IT MIGHT EXPLODE.
MAKE SURE GAUGE FITTINGS ARE IN GOOD
CONDITION AND DO NOT LEAK. Use extreme care when using Dry Nitrogen to
flush systems. Pressure in nitrogen cylinder
could be as high as 2500 psi. Nitrogen cylinder
must be equipped with approved pressure
regulator and pressure relief valve. Ensure that
your hoses have adequate ratings for pressure
involved and that all of your equipment is in
good condition.
When flushing with nitrogen there MUST Be
a pressure regulator on the tank with the
maximum pressure on the low side of the sealed
system (evaporator) at 150 PSI and at the High
side, 300 PSI.
The end of the flushing hose on this tank
regulator must be equipped with a hand shut-
off valve (Robinair No. 40380). Close hand
shut-off valve and adjust nitrogen regulator to
correct pressure before proceeding with flushing
procedure.
1. Remove compressor. Connect process coupling to
outlet tube of condenser.
2. Fasten cloth over other end of coil to prevent old oil
from spraying over room.
3. Connect hand shut-off valve on flushing hose to
process coupling.
4. Slowly open hand shut-off valve and allow nitrogen
to flow through condenser until discharge is clear.
5. Disconnect cap tube from evaporator. Flush
evaporator in same manner as condenser.
6. Flush cap tube. This is only possible if you have a
proper service valve adapter.
7. Reassemble system.
DO NOT EXCEED 300 PSIG.
DO NOT EXCEED 300 PSIG.
DO NOT EXCEED 150 PSIG.