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

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Twin Disc, Incorporated
Operation
Power Shift Transmission System Operator’s Manual #1020510
TDEC-400 Electronic Control System Components
Electronic Control
Monitors and controls the system through two wiring harnesses that attach to
the control through three connectors. The control has no preferred mounting
orientation.
Transmission Range Selector
The transmission range selector is customer supplied. Contact closures
communicate with the electronic control the operators demand for upshifts or
downshifts from the current range. An “instant neutral” switch is available to
instantly disconnect the pump from the engine if needed.
R-1 (Warm-Up)
This range is selected by downshifting from neutral. Solenoids are energized
to select the 2-5-8 input section clutch, and the 1-2-3, and 4-5-6 planetary
clutches in the output section. This results in the transmission shafts being
locked up, stalling the torque converter output shaft. The lockup clutch is not
allowed in the Warm-up mode.
N--NEUTRAL
Torque converter lockup clutch and transmission range clutches are disengaged.
Neutral
(N) will always be selected while starting the engine and during power
up of the electronic control system. A customer supplied neutral disconnect
relay will be de-energized and the neutral disconnect switch contacts opened.
Neutral will be achieved if the “instant neutral” switch is used to disconnect the
pump from the engine.
D-1
First range is engaged. This range is achieved by upshifting from neutral or
downshifting from D-2. The transmission input shaft will turn at 4.47 times the
transmission output shaft. Torque converter lockup clutch is automatically
applied based on turbine speed.