HPS Rotary Screw Compressor Units
070.700-IOM (MAR 21)
Page 31
Maintenance
Warning
Excessive pressure from expanding refrigerant
trapped between stop valve and solenoid may cause
gasket and O-ring failure and uncontrolled refriger-
ant release.
3. Close the service valve located between the compres-
sor and the liquid injection thermovalve.
4.
Carefully loosen the capscrews securing the
strainer
cover to the strainer. Allow pressure to relieve slowly.
5. When all
entrapped refrigerant has been relieved, care
-
fully remove the loosened capscrews (as liquid refriger-
ant is sometimes caught in the strainer), strainer cover,
and strainer basket.
6. Wash the strainer basket and cover in solvent and blow
clean with air.
7. Reassemble the strainer.
8. Open the service valve between the compressor and
liquid injection thermovalve and check for leakage.
9. Screw out the manual solenoid valve stem.
10. Carefully open the liquid supply service valve.
11. Leak test.
12. Close the disconnect switches for the compressor and
oil pump motor starters.
13. Start the unit.
Coalescer filter element(s)
When changing the coalescer filter element(s) it is best
practice to change the oil, the cartridge(s) in oil filters
OF-1 and OF-2 if applicable, and remove and clean the
following applicable strainer elements.
Notice
Use of
filter elements other than Frick may cause
warranty claim to be denied.
1. See
, Steps 1 to 8.
2. Loosen the manway cover retainer bolts, remove
retainers, manway cover, and cover gasket. Discard the
cover gasket.
3.
Remove and retain the nut securing the coalescer filter
retainer.
4.
Remove the retainer, coalescer filter element, and 2
O-rings. Discard the filter elements.
5.
Install a new coalescer filter element(s).
Notice
Frick SuperCoalescer
™
element (with drain feature) must
be installed with the 'DRAIN DOWN' tag on the bottom
at the 6 o'clock position.
Caution
Seat element in center of locating tabs on separator
bulkhead.
6.
Replace the coalescer filter retainer and nut. Tighten
the nut to 21 ft-lb (28.47
N⋅m)
torque.
Caution
Do not overtighten nut. Excessive torque can damage
the element and result in excessive oil carryover.
7.
Install the jam nut and tighten.
8.
Install new manway gasket and replace manway cover.
9.
Tighten
the manway bolts to 300 ft-lb (406.7
N⋅m)
on
the 580 DWP unit and 315 ft-lb (427.1
N⋅m)
on the 743
DWP unit.
Notice
Re tighten after the com pressor unit is repressurized,
because manway bolts loosen.
10. See
, Steps 9 to 14.
Changing oil
Warning
Do not mix oils of different brands, manufacturers, or
types. Mixing of oils may cause excessive oil foam-
ing, 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. Press the
STOP
key on the control panel to stop the
compressor unit.
2. Open the disconnect switch for the compressor motor
starter.
3.
Close the suction and discharge
service valves; also
close the liquid-injection and economizer service
valves, if applicable.
4.
Slowly
vent the separator to low-side system pressure
using the bypass line on the suction trap.
Notice
Recover or transfer all refrigerant vapor, in ac-
cordance with local ordinances, before opening to
atmosphere. The separator must be equalized to
atmospheric pressure.
Warning
Oil-entrained refrigerant may vaporize, causing a
separator pressure increase. Repeat venting and
recovery procedure, if necessary.
5. Open the drain valve(s) located on the underside of the
separator and drain the oil.
6.
Drain the oil filter(s) OF-1 and, if ap plicable, the oil
coolers and filter OF-2.
7.
Remove the old filter cartridges, then install new ones,
as previously described in the
