Frick RXB PLUS - MAINTENANCE; General Instructions for Replacing Compressor Unit Components

RXB PLUS ROTARY SCREW COMPRESSOR UNITSS70-101 IOM
Page 36
MAINTENANCE
MAINTENANCE
This section provides instructions for normal maintenance,
a recommended maintenance program, troubleshooting and
correction guides, typical wiring diagrams, and typical P and I
diagrams.
THIS SECTION MUST BE READ
AND UNDERSTOOD BEFORE AT-
TEMPTING TO PERFORM ANY
MAINTENANCE OR SERVICE TO THE UNIT.
CLOSE ALL COMPRESSOR PACK-
AGE ISOLATION VALVES PRIOR
TO SERVICING THE UNIT. FAILURE
TO DO SO MAY RESULT IN SERIOUS INJURY.
NORMAL MAINTENANCE OPERATIONS
When performing maintenance
you must take several precautions
to ensure your safety:
1. If the unit is running, push [STOP] key to shut down the
unit.
2. Disconnect power from unit before performing any main-
tenance.
3. Wear proper safety equipment when the compressor unit
is opened to the atmosphere.
4. Ensure adequate ventilation.
5. Take necessary safety precautions required for the re-
frigerant being used.
COMPRESSOR SHUTDOWN and START-UP
For seasonal or prolonged shutdown, the following pro-
cedure should be used:
1. Push [STOP] key to shutdown the unit.
2. Open the disconnect switch for the compressor motor
starter and oil pump motor starter (if applicable).
3. Turn off power.
4. Close suction, discharge, suction check valve bypass, and
liquid injection service valves. Attach CLOSED TAGS.
5. Shut off cooling water supply valve to the oil cooler, if
applicable. Attach CLOSED TAG.
6. Protect the oil cooler from ambient temperatures below
freezing or remove the water heads.
NOTE: The unit should be inspected weekly during shut-
down. Check for leaks or abnormal pressure. Manually
rotate the compressor. Consult motor manufacturer for
recommendations.
To start up after a seasonal or prolonged shutdown, the
following procedure should be used:
1. Perform routine maintenance. Change oil and replace fil-
ters. Check strainers.
2. Any water necessary for the operation of the system that
may have been drained or shut off should be restored or
turned on. If the oil cooler heads were removed, reinstall
and remove tags.
3. Open suction, discharge, and liquid injection service valves
and remove tags.
4. Compressor unit is ready for prestart checks. Refer to
PRESTART CHECKLIST.
GENERAL INSTRUCTIONS FOR REPLACING
COMPRESSOR UNIT COMPONENTS
When replacing or repairing components which are exposed
to refrigerant, proceed as follows:
1. Push [STOP] key to shutdown the unit.
2. Open disconnect switches for the compressor motor starter
and the oil pump motor starter (if applicable).
3. Close discharge service valve.
4. SLOWLY vent the component to low-side system pres-
sure using suction check valve bypass. Then close suction
service valve and suction bypass valve. NOTE: Recover or
transfer all refrigerant vapor, in accordance with local
ordinances, before opening to atmosphere. The compo-
nent MUST be equalized to atmospheric pressure be-
fore opening.
Oil-entrained refrigerant may va-
porize, causing a pressure in-
crease. Repeat venting and recov-
ery procedure, if necessary.
5. Make replacement or repair.
6. Isolate the low pressure transducer, PE-4, to prevent dam-
age during pressurization and leak test.
7. Pressurize the unit and leak test.
8. Evacuate the unit to 29.88" Hg (1000 microns).
9. Open suction and discharge service valves, and the low
pressure transducer. Readjust suction bypass valve.
10. Close disconnect switches for the compressor motor
starter and the oil pump motor starter, if applicable.
11. The unit is ready to put into operation.
SUCTION CHECK VALVE BYPASS
A 1/4" angle valve (HV-1 on P & I diagram) is installed be-
tween 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 1/4
to 1/2 turn 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.
OIL FILTER - SINGLE
To change the filter cartridge proceed as follows: