Frick HPS 2709 User Manual

070.750-IOM2 (JUN 22)
Page 18
HPS 273 and 407 Rotary Screw Compressor
Operation
If you expect the compressor to operate below 24 barg
(350 psig) discharge pressure, you can perform the slide
valve or stop travel check while the compressor is running.
Checking the slide stop travel
1. Run the slide valve to its minimum position (unloaded).
2. Run the slide stop to its minimum position and then
move the slide stop to its maximum endpoint.
The full travel of the slide stop from its minimum endpoint
to its maximum endpoint corresponds to the compressor’s
selected Vi range, which is either 2.2 Vi to 5.0 Vi, 1.7 Vi to
3.0 Vi, or 1.3 Vi to 1.96 Vi.
Checking the slide valve travel
1. Place the slide stop at its minimum endpoint.
2. Move the slide valve to its minimum endpoint (SV
unloaded) and then its maximum endpoint (SV is fully
loaded).
This provides the absolute capacity (CAPabs) range of the
compressor from minimum to maximum load.
If you expect the compressor to operate above 24 barg
(350 psig) discharge pressure, perform the slide valve or
stop travel check while the compressor is not running. The
process of operating the slide valve and slide stop from its
minimum endpoint to its maximum endpoint is the same
as the sequence described above. What is different is that
it requires an external source of pressure.
For more detailed calibration instructions refer to
090.040-O, Quantum HD Control Panel.
Using an external source of pressure
If the compressor has an oil pump capable of providing a
minimum of 3.8 bar (55 psi) differential pressure then it is
usable. Be aware however, that it also pumps oil to the
compressor and it is critical to drain all oil from the com-
pressor before startup.
If the compressor unit is not equipped with an oil pump,
an alternative is to use a small portable service oil pump.
If oil pumps are not available, it is possible to use nitrogen
gas (N
2
) or pressurized dry air. In this case, close off and
purge the compressor before performing the travel check.
After nishing the calibration, place the compressor under
a vacuum and open any stop valves.
Whether using an oil pump, nitrogen gas, or dry air the
compressor package needs to be designed with the nec-
essary access points and isolation valves.
Note: In most cases an external source supplying 3.8 barg
(55 psig) is sufcient to move the slide valve and
slide stop to their minimum and maximum travel
positions. If it requires higher pressure than this to
move the slide valve and slide stop then it is likely
that there is something wrong with the compressor
and it need to be investigated.
Warning
Never provide more than 17.2 bar (250 psig) external
pressure as this may result in signicant damage to
the compressor and bodily harm.
Initial start-up procedure
After performing the prestart check, the compressor unit
is ready for start-up. In low ambient conditions, have oil
heaters and heating wires on for 24 h before start-up. It is
important that an adequate gas load be available to load
test the unit at normal operating conditions. Keep the
following points in mind during initial start-up:
• For correct and safe operation, run the compressor at
the correct speed and discharge pressure. At any speed,
exceeding design conditions creates a potential hazard.
• Immediately after start-up, adjust the oil cooling
system. After 1 h to 3 h, adjust it again after operating
conditions are within expected parameters.
• Pull and clean suction strainer after 24 h of operation.
If it is excessively dirty, repeat every 24 h until the
system is clean. Otherwise, follow the normal
maintenance schedule.
• Frick strongly suggests completing a baseline vibra-
tion analysis for frequencies up to 7,000 Hz at normal
operating conditions so that you can monitor bearing
life can regularly. This means the compressor can
continue to operate and avoids an unnecessary
teardown inspection to check the bearings.
Normal start-up, shutdown, and standstill proce-
dures
1. Conrm that system conditions permit starting the
compressor.
Notice
Ambient temperatures need to be high enough to
prevent excessive condensing; otherwise, initiate oil
heaters 24 h before start up. If using heat tracing,
the wire selected needs to be based on the highest
expected saturation temperature that the system
operates at.
2. Start the unit.
3. Observe the compressor unit for mechanical tight-
ness of the external piping, bolts, and valves. Ensure
that the machine has no oil and vapor leaks. If any of
these occur, shut down the compressor and correct the
problem as necessary using good safety precautions.
Note: The rate of discharge pressure increase during
startup must be slow enough that refrigerant can’t
condense. This very often requires a regulated gas
by-pass valve from the outlet of the package to the
inlet side of compressor to prevent the discharge
temperature from increasing too slowly.

Frick HPS 2709 Specifications

General

Brand	Frick
Model	HPS 2709
Category	Air Compressor
Language	English