Tachospeedometer; General Information; Tachospeedometer Ар70.3813 - Belarus 80.1 Operation Manual

2.7 Tachospeedometer

2.7.1 Genral information
The tachospeedometer shows the following operation parameters:
- total operating time of the engine;
- tractor travel speed;
- rear PTO revolutions;
- speed sensors operating capacity;
- overvoltage in the tractor on-board network annunciation.
Tachospeedometer АР70.381 can be installed on tractors "BELARUS-80.1/82.1/820" or
combined undicator unit КД 8083.
2.7.2 Tachospeedometer АР70.3813
Tachospeedometer АР70.3813 is shown in figure 2.7.1.
1 – engine revolutions scale, min
network (red color); 3 – indicator of rear PTO revolutions in 1000 min
indicator of rear PTO revolutions in 540 min
PTO revolutions; 6 – indication display (LCD) of total operating time of the engine and tractor travel
speed; 7– needle indicator of the engine crankshaft speed.
Tachospeedometer АР70.3813 operation order is as follows:
When the tractor is stopped, after setting the starter and instrument switch to position "I" on display
6 (figure 2.7.1), the engine running hours (h) will appear.
After engine start needle indicator 7 moves along round scale 1 for indication of engine crankshaft
speed. At the same time, the indication of the calculated rotation speed of the rear PTO (min-1) appears
on display 5 - on scale 3 for the rear PTO in 1000 min-1 mode and on scale 4 for the rear PTO in 540
min-1 mode. Rear PTO rotational speed is calculated by the signal of the phase winding of the generator.
When the tractor moves, display 6 shows the estimated speed of the tractor (km / h), while the
indication of the running time of the engine disappears. Indications of speed are carried out by a signal
from a sensor mounted on the final drive gear of a wheel rotating at a lower frequency. Estimated
speed is somewhat higher than actual, because skidding of the tractor is not taken into account.
If, during tractor movement, instead of speed indications digit "02...07" appear on display 6,
and in 121 seconds digit "0" appears on the right side of display 6 it means there is no signal from
the right speed sensor. The error has to be eliminated. If, during tractor movement, instead of
speed indications digit "02...07" appear on display 6, and in 121 seconds digit "0" appears on the
left side of display 6 it means there is no signal from the left speed sensor. The error has to be
eliminated. There are no speed indications on display 6. To restore speed indications it is neces-
sary to eliminate the above mentioned errors.
The signaling device 2 of the increased voltage of the on-board network of the tractor lights up
when the supply voltage of the on-board network exceeds 18 V and turns off when the supply voltage
drops below 16 V.
Annuciator 2 of overvoltage in the tractor on-board network lights up when the supply voltage
of the on-board network is above 18V and turns off when the supply voltage drops below 16V. During
illumination of annunciator 2 the tachospeedometer does not work. When voltage in the tractor on-
board network rises above 18V, lamps, illuminating the tachospeedometer, can break down, if they
were turned on. In this case it is necessary to replace the tachospeedometer illumination lamps.
ATTENTION: WHEN THE TRACTOR ON-BOARD SUPPLY NETWORK VOLTAGE RISES
ABOVE 18V, THE TACHOSPEEDOMETER TURNS OFF COMPLETELY AND RESTORES ITS
OPERATING PERFORMANCE WHEN ON-BOARD VOLTAGE DROPS BELOW 16V!
-1 ; 2 – annunciator of overvoltage in the tractor on-board
mode (light indicator); 5 – indication display of rear
-1
Figure 2.7.1 – Tachospeedometer АР70.3813
34
80-0000010B OM
-1 mode (light indicator); 4 –