Ingersoll-Rand Doosan HP675WCU-T3, Operation & Maintenance Manual

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Electrical Operation & Maintenance Manual
Book 22826226 95
Digital Inputs and Outputs
The WEDGE controller scans digital inputs such as switch contacts. These are either “ON”
(24V DC) or “OFF (0V DC). These digital inputs are connectd to switches within the package
such as the key start switch, air filter switches and IQ filter switches.
The WEDGE controller provides 24V DC digital outputs to control solenoids, start compressor
and DC heaters. These are 24V DC “ON” and Zero Volt DC “OFF”. They are current limited
and short circuit protected.
Controller Outputs:
The WEDGE controller has three different types of outputs: frequency, pulse width modulated
(PWM) and 24 VDC digital (ON / OFF). The frequency output is used as a throttle signal for
the engine.
The WEDGE controller varies the frequency from 150 Hz to 375 Hz. The frequency signal is
a 50% duty cycle, 24V DC, square wave. This throttle signal is used with the Cummins engine.
The PWM signal is used as a throttle signal for the Caterpillar engine. It has a base frequency
of 500 Hz and the duty cycle varies from 10% to 90%.
Pressure Control
The discharge pressure is controlled by manipulating the engine speed and compressor inlet
valve position. The inlet valve position is controlled pneumatically and the engine speed
setpoint is determined by the WEDGE controller. The WEDGE measures the pneumatic
system regulation pressure and computes an engine throttle setting. This throttle setting is
sent to the engine via the frequency throttle, PWM or J1939 throttle, depending on which
technique is used. The engine controller will control engine speed to this throttle setting.
Electronic Engine
This machine contains an emissions certified diesel engine. In order to meet the emissions
requirements, the engine has an electronic control system.
The control system handles all the monitor, alarm and control functions for the engine. The
WEDGE controller communicates with the engine controller over the J1939 CAN network.
The WEDGE controller receives diagnostic and run time data from the engine over the J1939
CAN network.
J1939 Data Link - The CAN network is a single pair shielded cable within the W1 main
harness. The termination resistors (Terminator) are important to prevent reflections on the
transmission line and must be in place for the network to function properly. The shield from the
cable is connected to the machine metal at the WEDGE controller end.
The connection must be properly made with good metal to metal contact between the wire
terminal and the machine metal.
The engine diagnostics connector is located on the left side of the engine. This is used to
connect the engine manufacturers service tools to the CAN network. This connector also
provides 24 VDC power to these service tools.