Reduction Unit Electro-Hydraulic Control - Belarus 1822.3 Operator's Manual

3.4 Reduction unit electro-hydraulic control

The electro-hydraulic control of the gearbox reduction unit consists of the following
basic elements:
- annunciators 15 and 14 (figure 3.4.2) on a control panel 1, located in the tractor
cab;
- a lever 3 for shifting the speeds and the passes of the gearbox reduction unit;
- a sensor of GB neutral position 5;
- sensors 7 and 8, installed in the hydraulic cylinder switching the gearbox reduction
unit;
- a valve group 6, located at the top on the GB cover;
- connecting cables 4 with sockets 9.
The system is powered from on-board electrical line through a fuse, located in the
fuse block 2. The power supply voltage is delivered to the system after the starter and in-
strument switch has been turned into position "I" - Instruments on", but it is possible to shift
the reduction passes only after the engine is started, with the hydraulic system pump on.
On the lever 3 handle there are buttons 10 and 11 and annunciators (led-lamps) 13
and 12 of lower and higher reduction pass engagement, accordingly. On the panel 1 there
are duplicate annunciators 15 and 14 of lower and higher reduction pass and reduction
control relay.
The systems allows switching reduction passes only with the lever 3 in neutral posi-
tion (contacts of the sensor 5 of GB neutral position are closed).
ATTENTION: SWITCH BETWEEN THE GB REDUCTION PASSES ONLY WITH
THE TRACTOR STOPPED!
Signals to the annunciators 13, 12 and 15, 14 come from the respective pressure
sensors 8 and 7.
After the engine start-up the lower reduction pass turns on. Hereby the annunciators
13 and 15 must stay on.
The higher reduction pass shall be switched by pressing the button 11. Hereby the
annunciators 13 and 15 must go out, and the annunciators 12 and 14 must light up.
Switching from the higher reduction pass to the lower one is performed by pressing
the button 10.
The engine can be started only when the GB range shifting lever 1 (figure 2.13.1) is
set into neutral position.
The electrical circuit diagram of the reduction unit electro-hydraulic control is intro-
duced in Annex A.
Figure 3.4.1 – Allocation of components of reduction unit electro-hydraulic control
on the gearbox
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