RWB II ROTARY SCREW COMPRESSOR UNITS
OPERATION
S70-200 IOM
Page 21
INITIAL START-UP
Initial start-up must be performed under the supervision of a
FRICK authorized start-up representative to prevent voiding
the compressor warranty. Prior to the start-up, the prestart
check (see list in FORMS section) must be accomplished.
INITIAL START-UP PROCEDURE
Having performed the checkpoints on the prestart check list
the compressor unit is ready for start-up. It is important that
an adequate refrigerant load be available to load test the
unit at normal operating conditions. The following points
should be kept in mind during initial start-up.
1. For proper and safe operation the compressor must be
run at the proper speed and discharge pressure. Exceeding
design conditions creates a potential hazard.
2. Rotate and lubricate motor bearings according to
manufacturer’s recommendations PRIOR to start-up as re-
quired.
3. On units with prelube system a differential pressure of 55
PSI between suction and discharge pressures must be
achieved within five minutes of start-up or the unit will shut-
down on “Comp. Differential”.
4. After running the unit for approximately three hours, ad-
just liquid injection oil cooling if applicable. If unit has
thermosyphon or water cooled oil cooling, adjust water con-
trol valve to cooler.
The compressor slide valve and slide stop potentiometers
should be calibrated.
5. Stop the unit, lock out the motor main disconnect, check
the hot alignment, and adjust as necessary.
NORMAL START-UP PROCEDURE
1. Confirm system conditions permit starting the compressor.
2. Press the [RUN] key.
3. Allow the compressor to start-up and stabilize. Press the
[AUTO] key immediately below the V ratio label on the oper-
ating display screen. Press the [AUTO] key immediately be-
low the SV POS label on the operating display. The compres-
sor is now operating in the automatic mode.
4. Observe the compressor unit for mechanical tightness of
the external piping, bolts and valves. Ensure that the ma-
chine is clean from oil and refrigerant leaks. If any of these
occur, shutdown the compressor and correct the problem as
necessary using good safety precautions.
5. RETIGHTEN MANWAY BOLTS at condenser design pres-
sure (while system is running).
RESTARTING COMPRESSOR UNIT AFTER CONTROL
POWER INTERRUPTION (PLANT POWER FAILURE)
1. Check variable setpoints.
2. Follow normal start-up procedure.
to provide high pressure gas from a high stage compressor
discharge for booster applications in which the operating pres-
sure differential on the booster compressor is insufficient to
close the suction check valve.
Frick provides a power assist kit consisting of a mounted
and wired solenoid valve and timer on all RDB booster com-
pressors. Introduction of high discharge pressure gas is made
to the check valve. A timer limits the high pressure gas to
only thirty seconds duration since intermediate gas pressure
and spring tension are sufficient to maintain closure on unit
shutdown. A metering valve is also provided for use as a
service valve and to allow discharge gas flow regulation to
prevent excessive force and resulting closure “hammering”.
