070.250-IOM (APR 11)
Page 14
408 MM ROTARY SCREW COMPRESSOR
INSTALLATION
OIL COOLING REQUIREMENTS
Compressor oil needs to be cooled to control the discharge
temperature, maintain proper oil viscosity and to preserve
the life of the oil. Normally the discharge temperature will
be in the 170° - 180°F range (see CoolWare
™
).
One application that typically requires higher discharge
temperatures (as high as 250°F) is natural gas gathering at
the wellhead. Moisture is normally present in the gas and
it is imperative that the discharge temperature be at least
30°F higher than the discharge dew point temperature for
the gas. Run Coolware with the “Water Saturated” block
checked to get the discharge dew point temperature for
your application. Oil temperatures as high as 170°F can
be used to achieve the necessary discharge temperature
to prevent moisture from condensing in the oil separator.
Contact Johnson Controls–Frick for additional information
for natural gas compression.
The main oil injection line that is connected to port SM1
must have a regulating valve to permit adjustment of the
oil flow to maintain the desired discharge temperature at
all times.
The use of a three-way mixing valve is recommended to
keep the oil temperature in the normal range of 120° -
140°F. The valve will provide warm oil to the compressor
quickly, reducing the pressure drop caused by cold, viscous
oil. This ensures proper oil flow and temperature over the
full range of operating conditions.
DEHYDRATION / EVACUATION TEST
Evacuate
the system to 1000 microns. Valve off the vacuum
pump and hold vacuum for one hour.
PASS
– Vacuum cannot rise more than 500 microns during
one hour hold period.
FAIL
– Vacuum rise is more than 500 microns during one
hour hold period. Identify and repair any system leaks.
Repeat vacuum test until requirements are met.
ELECTRICAL INSTALLATION
SLIDE STOP TRANSMITTER
The slide stop transmitter (Figure 5) measures the position
of the slide stop (SS) using a 20 to 4 mA signal to cover
the range of minimum to maximum VI. The signal is sent
to your control system so that it can adjust the position of
SS according to system pressures. The correct SS position
is important to achieve the most efficient compressor
operation. Connect to +/- and signal as shown in the
wiring diagram in Figure 6. Refer to Frick compressor panel
instructions 090-020 O for calibration procedure.
Figure 5 - Slide Stop Transmitter
Figure 6 - Wiring Diagram for Slide Stop Transmitter
CAPACITY SLIDE VALVE TRANSMITTER
The slide valve transmitter (Figure 7) measures the position
of the slide valve (SV) and sends a 4 to 20mA signal to your
control system. See Figure 8. The controller will adjust the
position of the SV according to the motor load setpoint.
The correct position is important to properly load the
compressor and motor. It is important not to overload the
compressor and motor. Observe the maximum power input
and ensure design limitations are not exceeded. Connect
to +/- and signal as shown in the wiring diagram, Figure 8.
Refer to Frick compressor panel instructions for calibration
procedure 090-020 O.
END VIEW
DIN CONNECTOR
STAINLESS STEEL WELL
HEAT ISOLATOR
CAST ALUMINUM HOUSING
COMPRESSOR UNLOAD CYLINDER
SHADED AREA SHOWS
CAPACITY LINEAR TRANSMITTER
Figure 7 - Capacity Slide Valve Transmitter
