RWF ROTARY SCREW COMPRESSOR UNITS
MAINTENANCE
S70-600 IOM (OCT04)
Page 22
GENERAL INSTRUCTIONS FOR REPLACING
COMPRESSOR UNIT COMPONENTS
NOTE: See Publication S70-660 SM for procedures cover-
ing replacement motor and compressor mounting.
When replacing or repairing components which are exposed
to refrigerant pressure proceed as follows:
1.
Push
[STOP]
key on control panel to shut down unit.
2.
Open disconnect switches for compressor and pump
motor starters.
3.
Close suction and discharge service valves, also liquid
injection and economizer service valves, if applicable.
4.
SLOWLY
vent separator to low-side system pressure
using the bypass line on the suction trap.
NOTE: Recover
or transfer all refrigerant vapor, in accordance with local
ordinances, before opening to atmosphere.
The separator
MUST
be equalized to atmospheric pressure.
Oil-entrained refrigerant may va-
porize, causing a separator pres-
sure increase. Repeat venting and
recovery procedure, if necessary.
5.
Make replacement or repair.
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.
9.
Open suction and discharge service valves, low pressure
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) MAIN SINGLE/DUAL
RWF compressor 100 through 480 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) without unit shutdown.
Use of filter elements other than
Frick may cause warranty claim
may 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 micro-
processor 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 ser-
vice valves of the standby filter.
Open inlet service valve slowly to
prevent a sudden pressure drop
which could cause an oil filter dif-
ferential alarm.
2.
Close outlet then inlet service valves of filter being serviced.
3.
Open bleed valve and purge pressure from the oil filter
cartridge.
NOTE: Recover or transfer all refrigerant vapor,
in accordance 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 assembly. 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 element and 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 canister, securing with
screws tightened to 7 ft-lb torque. Fill the canister with new
Frick refrigeration oil.
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.
Use of filter elements other than
Frick may cause warranty claim
may to be denied.
Replace the gasket and reinstall the canister cover. Torque
cover bolts first to finger tight, then 65 ft-lb, then 130 ft-lb.
7.
Close purge valve.
8.
Open outlet service valve and leak test.
9.
Filter is ready to place in service.
STRAINER - DEMAND OIL PUMP
To clean the demand oil pump strainer, the unit must be shut
down. The procedure is as follows:
1.
Push
[STOP]
key on microprocessor panel to shutdown
unit, then open disconnect switches for compressor and oil
pump motor starters.
2.
Close strainer inlet service valve.
3.
Open drain valve located in the strainer cover and drain
oil into a container.
4.
Remove capscrews securing strainer cover, strainer
cover, gasket and element. Retain gasket.
5.
Wash element in solvent and blow clean with air.
6.
Wipe strainer body cavity clean with a lint free clean
cloth.
7.
Replace cleaned element, gasket and reattach
cover using retained capscrews.
8.
Close drain valve and open strainer inlet service
valve.
9.
Check for leakage.
10.
Close disconnect switches for compressor and oil pump
motor starters.
11.
Start unit.