RXF ROTARY SCREW COMPRESSOR UNITS
MAINTENANCE
070.410-IOM (JAN 12)
Page 24
suction check valve bypass. Close disconnect switches for
the compressor and (if applicable) the oil pump motor start-
ers. Start the unit.
COALESCER OIL RETURN STRAINER
1. Push
[STOP]
key to shut down the unit. Open disconnect
switches for the compressor.
2. Isolate the package by closing all package valves to the
system. Tag all closed valves.
Open any sole noid valves or other
valves that may trap liquid between
the isolation valves and other pack-
age valves to prevent injury
or damage to components.
SLOWLY
vent separator to low-side system pressure using
the suction check valve bypass.
NOTE: Recover or transfer
all refrigerant vapor, in accor dance with local ordinances,
before opening to atmo sphere.
The separa tor
MUST
be
equal ized to atmo spher ic pres sure.
Oil entrained refriger ant may vapor-
ize, causing a separa tor pressure
increase. Repeat transfer and recov-
ery procedure, if neces sary.
3. Close strainer isolation valves. Remove the large plug
from the bottom of the strainer and remove the element
from the strainer.
4. Wash the element in solvent and blow clean with air.
5. Replace the cleaned element and removed plug. Open
strainer isolation valves.
6. Isolate the low pressure transducer, PE-4, to prevent dam-
age during pressurization and leak test.
7. Pressurize and leak test. Evacuate unit to 29.88" Hg (1000
microns).
8. Open the suction and discharge service valves, and the
low pressure transducer. Close discon nect switches for the
compressor. Start the unit.
LI Q UID INJECTION STRAINER
To clean the liq uid injection strainer the unit must be shut
down. The procedure is as follows:
1. Push
[STOP]
key to shut down the unit, then open discon-
nect switches for the compressor.
2. Close the liquid supply service valve located before the
liquid solenoid.
3.
Immediately screw in the manual solenoid valve stem
to relieve liquid refrigerant pressure trapped between the
solenoid and the service valve.
4. Close the service valve located between the compressor
and the liquid injection thermal expansion valve.
5. Carefully loosen capscrews securing the strainer cover to
the strainer. Allow pressure to relieve slowly.
6. When all entrapped refrigerant has been relieved, carefully
remove loosened capscrews (as liquid refrigerant is some times
caught in the strainer), strain er cover, and strainer basket.
7. Wash the strainer basket and cover in sol vent and blow
clean with air.
8. Reassemble the strainer.
9. Open the service valve between the compressor and the
liquid injection thermal expansion valve, purge entrained air,
and check for leakage.
10. Screw out the manual solenoid valve stem.
11. Carefully open the liquid supply service valve.
12. Leak test.
13. Close disconnect switches for compressor starter.
14. Start the unit.
OIL PUMP STRAINER (Optional)
To clean the full-lube oil pump strainer, the unit must be shut
down. The proce dure is as follows:
1. Push
[STOP]
key to shut down the unit, then open the
discon nect switches for the compressor and (if applicable)
the oil pump motor starters.
2. Close strainer service valves.
3. Open the drain valve located in the strainer cover and
drain the oil into a container.
4. Remove the capscrews securing the strainer cover, strainer
cover gasket, and element. Retain the gasket.
5. Wash the element in solvent and blow it clean with air.
6. Wipe the strainer body cavity clean with a lint-free clean cloth.
7. Replace the cleaned element and gasket, then reattach
the cover using the retained capscrews.
8. Reinstall the drain plug and open the strainer service valves.
9. Check for leakage.
10. Close the disconnect switches for the compressor and
(if applicable) the oil pump motor starters.
11. Start the unit.
SUCTION CHECK VALVE BYPASS
A 1/4" angle valve is installed between the compressor and
suction flange that can be used as a suction valve bypass.
This feature has several uses including reducing starting
torque, improving oil quality, and relieving the refrigerant
to low side for servicing.
In most cases, the valve should be left open approximately 1 to
2 turns at all times. If the compressor back-spins or too much
oil foaming is experienced while venting, partially close valve
to slow speed of equalization. If system is on AUTO CYCLE and
short cycling occurs, the valve must be closed.
To relieve refrigerant to low side, close separator discharge
service valve. Slowly open bypass valve (if closed) and wait
for pressure to equalize. Close bypass and suction service
valves before evacuating the unit.
COALESCER FILTER ELEMENT
Use of coalescer filter elements
other than Frick may cause war-
ranty claim to be denied.
