070.610-IOM (JUL 21)
Page 34
RWF II Rotary Screw Compressor Units
Maintenance
4.
Slowly vent separator to low-side system pressure us-
ing the bypass line
on the suction trap.
NOTICE
Recover or transfer all refrigerant vapor, in accordance
with local ordinances, before opening to atmosphere.
The separator must be equalized to atmospheric pres-
sure.
WARNING
Oil-entrained refrigerant may vaporize, causing a
separator pressure increase. Repeat venting and re-
covery procedure, if necessary.
5.
Make replacement or repair.
NOTICE
Replace all gaskets and O-rings with new ones. Suction
Strainer: remove, inspect and clean as necessary and
replace using a new gasket.
6.
Isolate the low pressure transducer, PE-4, to prevent
damage during pressurization and leak test.
7.
Pressurize unit and leak test.
8.
Evacuate unit to 29.88 in. Hg (1000 microns).
9.
Open suction and discharge service valves, low pres
-
sure transducer, and also liquid injection and economizer
service valves, if applicable.
10.
Close disconnect switches for compressor and oil pump
motor starters.
11.
Unit is ready to put into operation.
12.
Perform checkpoints on prestart checklist, then start
unit.
Oil filter (OF-1) cartridge style
RWF II compressor units are furnished with one main
oil filter (OF-1). A second oil filter (OF-2) is installed as
optional equipment to facilitate the changing of the filter
element(s) witho
ut unit shutdown.
NOTICE
Use of
filter elements other than Frick may cause
warranty claim to be denied.
The procedure to change filter cartridge(s) is as follows:
1.
If a single oil filter is installed, push
[STOP]
key on mi-
croprocessor panel to shut down unit, then open discon-
nect switches for compressor and oil pump motor starters.
If
dual oil filters are installed, open the outlet, then inlet
service valves of the standby filter.
WARNING
Open inlet service valve slowly to prevent a sudden
pressure drop which could cause an oil filter differen
-
tial alarm.
2.
Close outlet then inlet service valves of filter being ser
-
viced.
3.
Open bleed valve and purge pressure from the oil filter
cartridge.
NOTICE
Recover or transfer all refrigerant vapor, in ac-
cordance with local ordinances, before opening to
atmosphere.
4.
Remove the plug from the bottom of the filter canister
and drain the oil. Remove the canister cover and discard
the gasket. Remove the screws securing the filter assem
-
bly. Pull the filter assembly from the canister and discard
the gasket and the element.
5.
Flush the canister with clean compressor oil; wipe dry
with a clean, lint-free cloth; and replace the plug.
6.
Install a new one-piece filter element*. Tighten the six
3/8 in. hex head cap screws to 10 ft-lb torque.
Figure 39: SuperFilter II - current design
*Before January 2010, the SuperFilter
™
II elements were
separate pieces. Follow step 6a in lieu of step 6 for this
design. After January 2010, the rod and nuts were elimi
-
nated and the end plate and gasket became part of the
filter. Refer to the Oil Filter page in the
070.610-SPL
for a
detailed graphic.
6a.
Install the new element(s) on the rod with all neces
-
sary hardware. Tighten the nut on the end plate to 10 ft-lb
torque. Then, while holding the nut with a wrench, apply
a second nut to act as a locknut. Replace the gasket and
reinstall the filter assembly into the canister, securing with
screws tightened to 30 ft-lb torque.
Figure 40: SuperFilter II - design pre-2010
WARNING
Do not mix oils of different brands, manufacturers, or
types. Mixing of oils may cause excessive oil foaming,
nuisance oil level cutouts, oil pressure loss, gas or oil
leakage and catastrophic compressor failure.
