S90-010 M FRICK
QUANTUM™ COMPRESSOR CONTROL PANEL
Page 20 MAINTENANCE
Set the DVM to read “DC”, and set the proper range. The
voltage reading must read a minimum of +4.98 Vdc. The
Power-I/O harness will have an associated voltage drop at
each board connection. As an example, if you are reading
the voltage at the first I/O board in the daisychain, and it
reads 4.98 Vdc, you can be assured that the voltage at the
subsequent connections for the remaining boards will be
lower yet. The voltage will need to be corrected for proper
operation of the system.
The cause for a low voltage reading could be:
• The Quantum™ power supply may need
adjustment (see the section on power supplies).
• The Power-I/O communications harness has a
problem (a new harness may be needed).
• A problem may exist with one of the I/O boards
(Digital or Analog).
• If the power LED is not lighted, check the cable
for proper connectivity. Note: Each board
provides the necessary connections to feed
all signals to the following connectors. If the
auxiliary Analog or Digital Board is not
present then a jumper plug (Part #
640B0039H01) must be installed to daisychain
the signals.
Active LED
The Analog Boards have an “Active” LED indicator on the
board that blinks when the board’s software is running.
If the “Active” LED is not blinking, check to ensure that the
EPROM is installed properly. The EPROM is located in
chip slot U13, near the power connector.
Analog Inputs
An Analog Input is the portion of the hardware that allows
devices such as temperature sensors and pressure
transducers, to interface with the Quantum™. The
software program within the Quantum™ is constantly
“looking” at these Input channels, via communications,
and based upon what the voltage or current level of the
channel is, will provide the necessary control for an
associated action. For instance, if the digital input for the
Oil Level Sensor is energized, and the Oil Separator
Temperature sensor signal causes the value to drop below
the setpoint, the Separator will determine that the Oil
Heater needs to be energized. (Digital Inputs are
discussed in the Digital Input section).
Analog inputs arrive at the board on connectors P1
through P8. Each of these connectors can receive two
channels (for a total of sixteen).
Each of the sixteen analog input channels is board
configurable to select for the following input signals:
• 4-20 mA
• 0-5 volt
• 1-5 volt
• ICTD
Refer to the Analog Board drawings and Analog Board
Settings pages that appear later in this section for specific
information and locations of jumpers. Also, see the section
entitled “Checking the Analog Inputs and Outputs”.
Analog Outputs
An Analog Output is the portion of the hardware that the
Quantum™ uses to provide control. With the Quantum™,
this output is typically a 4-20 mA signal that is outputted to
an external device. This device is usually a customer
specific application. Perhaps they are looking to simply
receive a signal back from the Quantum™ telling then the
Slide Valve Position, as an example.
Checking the Analog Inputs and Outputs
Some problems that are encountered involve
troubleshooting the Analog inputs and outputs. The
Analog I/O (Input / Output) Boards have eight Analog I/O
(DIO) board connectors labeled P1 through P8. The
external Analog devices are wired to a DIO connector
plug. Position 1 connects to the plus (+) of the external
device for channel 1, position 2 connects to the signal
(SIG) of the external device for channel 1 and position 3
connects to ground (GND) of the external device for
channel 1. Position 4 connects to the plus (+) of the
external device for channel 2, position 5 connects to the
signal (SIG) of the external device for channel 2 and
position 6 connects to ground (GND) of the external
device for channel 2, as shown below:
The Analog I/O Boards have numerous jumpers that must
be properly selected. There are sixteen analog input
channels that can be selected for 4-20 mA, 0-5 Vdc, or
ICTD. Channel #16 will also take the 0-5 Amp motor CT
as an input. All of these jumper settings are listed later in
this section (Analog Board Settings section). Besides
properly setting the hardware jumpers, each channel is
setup in software for the proper transducer type and
range, and each transducer must be calibrated through
the appropriate sensor calibration screen. Improper setup
of either the hardware or software will result in improper
operation or range.
The most common fault associated with the reading of the
analog channels other than hardware or software setup
problems fall into one of the following categories:
• Sensor fault
• Wiring problem
• Improper grounding of system.
An open wire, shorted wire, or faulty sensor will usually
give a reading at either the minimum or maximum end of
the range scale. An erratic reading or a reading that
seems to float up and down is usually indicative of a
grounding problem. When a single transducer or cable is
shorted to earth (or system) ground, this can show up as a
whole assortment of problem channels. The easiest way
GND
Channel 2
Channel 1
Channel 1
Signal
Channel 2
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