RXF ROTARY SCREW COMPRESSOR UNITS
MAINTENANCE
070.410-IOM (JAN 12)
Page 25
When changing the coalescer filter element, it is recom-
mended that the oil and oil filter be changed. Applicable
strainer elements should be removed and cleaned.
1. Refer to
CHANGING OIL
, Steps 1 thru 8.
2. Remove coalescer head and gasket. Discard the gasket.
3. Remove and retain nut securing coalescer filter retainer.
4. Remove retainer, coalescer filter element(s), and two
O-rings. Discard the filter element(s).
5. Install new coalescer filter element(s). NOTE: Frick SuperCo-
alescer
™
element (with drain feature), on Models 24–101, must
be installed with the "DRAIN DOWN" tag on the bottom at the
6 o'clock position.
Seat element in center of locating
tabs on separator bulkhead.
6. Replace coalescer filter retainer and nut. Tighten the nut
to 21 ft/lb torque.
DO NOT OVERTIGHTEN NUT
. Excessive
torque can damage the element and result in oil carryover.
Install jam nut and tighten.
7. Install a new head gasket and replace the coalescer head.
8. Tighten the head bolts, first to finger tight, then 65 ft-lb,
then 130 ft-lb.
NOTE: WHEN THE COM PRES SOR UNIT IS
REPRESSURIZED, RETIGHTEN SINCE HEAD BOLTS WILL
LOOSEN.
9. Refer to
CHANGING OIL
, Steps 9 thru 14.
CHANGING 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.
Shut down the unit when changing oil. At the same time all
oil filter cartridges must be changed and all oil strainer ele-
ments removed and cleaned. The procedure is as follows:
1. Push
[STOP]
key to shut down the unit.
2. Open disconnect switch for the compressor motor starter.
3. Close liquid injec tion service valves (if applicable).
4. Close discharge service valve.
SLOWLY
vent the separator
to low-side system pres sure using the suction check valve
bypass. Close suction valve.
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 vapor-
ize, causing a separator pressure
increase. Repeat venting and recov-
ery procedure, if neces sary.
5. Open drain valve(s) located on the underside of the sepa-
rator and drain the oil.
6. Drain oil filter, strainers, and oil cooler, if applicable.
7. Remove and install new oil filter element.
8. Remove, clean, and reinstall strainer ele ments in strainers.
9. Evacuate unit to 29.88" Hg (1000 microns).
10. Open suction service valve and pressurize the unit to
system suction pressure. Close the suction valve and leak test.
11. Add oil by attaching a suitable pressure-type hose to
the oil drain valve located on top of the separator. Using a
pressure-type oil pump and recommended Frick oil, open the
drain valve and fill the separator until oil level is midway in
the top sight glass.
NOTE: Evacuation of the oil separator
will assist the flow of oil into the unit. Also, fill slowly
because oil will fill up in the separator faster than it shows
in the sight glass.
See Oil Charge section.
12. Open discharge and liquid injec tion service valves.
13. Close disconnect switch for compressor motor starter.
14. Start the unit.
SUCTION STRAINER CLEANING PROCEDURE
1. Open disconnect switch.
2. Isolate the package by closing all package valves to the
system. Tag all closed valves.
Open any solenoid valves or other
valves that may trap liquid
between the isolation valves and
other package valves to prevent injury or damage to
components.
3. With liquid injection, close the manual hand valve upstream
of YY7 and manually open YY7 by turning in the manual
opening stem (clockwise viewed from below valve).
Failure to follow this procedure will
damage valve YY7.
4.
SLOWLY
vent the separator to low-side system pressure
using the suction check valve bypass.
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 vapor-
ize, causing a separator pressure
increase. Repeat transfer and recov-
ery procedure, if necessary.
5. Remove cover plate.
6. Remove strainer.
7. Clean strainer.
8. Reinstall the strainer in the proper direction (outboard
end is marked) and replace the gasket.
If the strainer is installed backwards,
it will be damaged.
9. Pressurize and leak test. Evacuate unit to 29.88" Hg (1000
microns).
10. First, reset solenoid valves to automatic position then
open all valves previously closed. Remove tags. Close dis-
connect switches for compressor. Start unit.