Twin Disc TA-90-8501, Operator'S Manual

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Twin Disc, Incorporated
Operation
Power Shift Transmission System Operator’s Manual #1020510
Clutch Valve Coils
Identical cartridge valves are used throughout the transmission system. The
cartridge valves are identified as transmission range clutch valve coils, #1
through #6, and converter lockup clutch valve coil. They are used for controlling
high pressure oil being directed to engage clutches. They are controlled with a
signal type that can control pressure full off, full on, or at intermediate levels as
needed for proper fracturing rig shifting and control. The oil flow/pressure
supplied to the clutch pack can be precisely controlled with these valves. This
is especially important when the control changes transmission ranges - turning
some clutches off and others on.
The resistance of these solenoid coils ranges approximately between 5 and
11 ohms depending on temperature.
The control is programmed with the appropriate resistance of each of the valves
and the wires to/from the valve and checks the external circuits continuously. If
it detects a value that is out of range, it shows a display message on the display
to alert the operator to check the circuit and the valve. This will alert the operator
if a wire is cut or shorted, or if the connector plug becomes disconnected, etc.
Filter Differential Pressure Switch
This sensor reacts to the pressure drop across the oil filter (inlet pressure vs.
outlet pressure). When the pressure drop reaches a high level (filter starting to
plug) the control will alert operator with a display message.
Transmission Oil Level Sensor
This customer supplied sensor will indicate EMPTY or FULL level of oil in the
transmission sump..
Transmission System Oil Temperature Sensor
This sensor is located in the torque converter outlet oil circuit. The sensor is a
variable resistance element that provides an analog signal to the control.