070.610-IOM (JUL 21)
Page 47
RWF II Rotary Screw Compressor Units
Maintenance
14.
These two voltages should be within 0.04 VDC of one
another.
15.
Test is complete.
Pressure transducers – replacement
1.
Shut off control power.
2.
Close the applicable transducer isolation valve.
NOTICE
To change the discharge pressure transducer (PE-3), it
will be necessary to depressurize the entire compres-
sor package. Follow "General Instructions For Replac-
ing Compressor Unit Components" before going to
step 3.
Figure 48: Pressure transducer color key
CABLE COLOR CODE
PIN 1
+ SUPPLY
PIN 2
DC COMMON
PIN 3
SIGNAL
CASE GND
2
3
1
3.
See the Figiure above to identify wiring harn
ess con-
nectors.
4.
Loosen screw and disconnect wiring harness connector
from transducer.
5.
U
nscrew the transducer using a wrench on the metal
hex at the base of the transducer.
Do not attempt to
loosen or tighten transducers by their top casing.
6.
Install new transducer.
7.
Reconnect the wiring harness to the transducer.
8.
Reopen the transducer isolation valve.
9.
Turn on control power.
NOTICE
The Pressure Transducer is factory set. If calibration
is required, refer to Analog Calibration Instruction in
publication
090.040-M.
Capacity linear transmitter – slide
valve
Figure 49: Capacity linear transmitter
END VIEW
DIN CONNECTOR
STAINLESS STEEL WELL
HEAT ISOLATOR
CAST ALUMINUM HOUSING
COMPRESSOR UNLOAD CYLINDER
SHADED AREA SHOWS
CAPACITY LINEAR TRANSMITTER
Replacement
The
Capacity Linear Transmitter is located on the end of
the
compressor unload cylinder, see Figure above.
The linear transmitter with hermetic enclosure is based on
the inductive measuring principle. It features removable
electronics (from the sensor well) eliminating the need
to evacuate the compressor for replacement. This type
of transmitter is dedicated to capacity control and is not
adjustable.
1.
Shut off control power.
2.
Remove
DIN connector plug from transmitter.
3.
Loosen cap screws.
4.
Remove transmitter unit.
5.
Install new transmitter unit.
6.
Tighten cap screws.
7.
Apply DIN connector plug to transmitter.
8.
Turn on control power.
NOTICE
For calibration instructions, refer to Quantum
™
HD
Operator's Manual,
090.040-O.
Troubleshooting the sensor
Ensure that the channel is properly configured on the
Cali-
bration
or
Analog
board setup screen for the type sensor
being used.
Check that supply voltage to the sensor is 12 VDC to 15
VDC on red and black wire for Channel 14, P7A terminal
strip of the Analog Board.
Check for a returning signal of:
•
1 VDC to 5 VDC for a transducer
•
4 mA to 20 mA for a linear transmitter
•
0 VDC to 5 VDC for a
Potentiometer
•
0.273 mA for an ICTD at 0C or ice water
Volume ratio control transmitter –
slide stop
Troubleshooting
Confirm the setup of channel 15 on the calibration or ana
-
log board #1 setup screen.
Troubleshoot the slide stop linear transmitter on chan-
nel 15 of the P7B terminal strip of the analog board in the
same manner as the slide valve transmitter.
Replacement
The volume ratio control transmitter is located on the
right side of the compressor (facing the shaft) at the inlet
end. See Figure below.
The linear transmitter with hermetic enclosure is based on
the inductive measuring principle. It features removable
electronics (from the sensor well) eliminating the need to
evacuate the compressor for replacement. This type of
transmitter is dedicated to volume ratio control and has no
user adjustments.
