Belarus 1523, Operating Manual

Page: 69 / 312

BELARUS-1523/1523 В /1523.3 /1523В.3 Construction and Operation
68
and alarm pressure indicator installed in
the heat-exchange branch pipe are used.
The normal diesel heat condition as to
lubricating oil is within 80…120 ° C.
The Radiator is of finned tubular type. A
steam valve in the radiator filler neck
maintains the pressure within the range
of 0.045…0.05 MPa while the air valve
maintains the vacuum within the range of
0.01…0.08 MPa.
The Fan runs in two operating modes:
• automatic;
• forced.
The automatic mode is provided by a
viscous friction coupling as follows: at the
coolant temperature below 80 ° C the re-
turn spring (7) retains the valve (10) in
the closed state; viscous fluid flows into
the coupling reserve cavity; the driving
(11) and driven (13) disks are rotating
with a gap in-between them and, thus,
ensure the minimum rotational speed of
the fan (in this case, the fan rotational
speed shall not exceed 1,500 rpm).
1 – fan blade; 2 – driven plate; 3 – opening for
detent; 4 – detent nut; 5 – detent; 6 – stem; 7 –
return spring; 8 – spring holder; 9 – follower; 10 –
valve; 11 – driving plate; 12 – clutch; 13 – driven
plate; 14 – drive shaft; 15 – water-pump pulley;
16 – water pump;17 – release rod
Should the engine coolant temperature
exceeds 80 ° C, the thermosensitive ele-
ment will open the valve (10) acting
through rod (17) and piston lifter (9)
against the force of the return spring (7).
The viscous fluid flows over into the head
cavity and fills in the gap between the
driving and driven plates due to that the
disks are engaged, and the fan is turned
on in its normal operating duty.
ATTENTION! With the cooling system
compressor running, the
forced mode
of fan operation should be chosen.
To switch the fan over to the forced
(continuous) operation mode, proceed as
follows:
• turn out the nut (4) of the detent (5) by
4…5 revolutions (about 5 mm);
• turn the fan by hand, so that the de-
tent (5) enters hole (3) in the driving
plate (11).
If necessary, press the detent (5) by
hand to lock the driving and driven
plates.
Electric Equipment and Starting System