Component Test And Maintenance; Vacuum Pump; Pressure Sensor P1; Pressure Switch P2 - Bosch ACS 810 Repair Instructions

12. Component test and
maintenance
12.1

Vacuum pump

!
The vacuum pump oil must always be changed after
30 hours of operation.
Property
Operating voltage
Frequency
Vacuum pump oil filling capacity
Output
Max. vacuum
To check correct operation of the pump, carry out the
following steps:
1. Check the oil level in the vacuum pump.
i
The oil level should be in the middle of the
sight glass between the "full" and "empty" marks.
2. Attach pressure gage to intake connection.
3. Start vacuum generation.
"
A vacuum of 0,033 mbar must be achieved.
12.2

Pressure sensor P1

1. Check whether a voltage of 24 Volt (DC) is present
between pin 1 (-) and pin 2 (+).
i
If no voltage is present, check the control PCB and
replace if necessary.
2. Check whether an output signal is present between
pin 1 (-) and pin 3 (+).
i
The output signal is between 0 V and 10 Volt, i.e.
1.0 Volt corresponds to 1.6 bar. If the pressure
gage shows 3 bar relative (4 bar absolute), the
voltage must be 2.5 Volt.
i
When replacing the pressure sensor, a special
thread sealant (e.g. Loctite 542) must be used.
Robert Bosch GmbH
Component test and maintenance | ACS 810 | 27 |
12.3
i
The pressure switch is normally closed between
contacts 1 and 2, and open between contacts 1
and 4. The pressure switch opens at 16 bar.
To check the pressure switch, carry out the following
steps:
1. Close V1 - V4.
Value/range
2. Remove the red hose from the internal refrigerant
230 VAC ± 10 % cylinder and connect the red service hose to the
50/60 Hz
internal refrigerant cylinder.
590 ml
3. Close both valves on the refrigerant cylinder.
283 l/min
4. Remove the blue hose from the internal refrigerant
0,033 mbar
cylinder and connect a pressure gage using a
T-piece.
5. Open V4.
6. Open V1.
7. Start the recovery function.
8. As soon as the pressure reaches 16 bar, recovery
must be ended, and the message
PRESSURE VALUE TOO HIGH
9. Drain the pressure into the internal refrigerant
cylinder by opening the high pressure valve.
i
When replacing the pressure switch, a special
weight sealant must be used.
12.4
i
The expansion valve is a pressure control valve
that is set to a value between 2 and 2.3 bar and
maintains a constant pressure before the oil
separator.
!
The refrigerant cylinder must contain at least 6 kg
of refrigerant.
1. Connect the low pressure service hose to the
connection after the expansion valve using the
adapter supplied.
2. Close HP and LP valves.
3. Start the recycling function.
"
After around 10 minutes, the pressure value must be
between 2 and 2.3 bar.
i
Adjust the value by turning the hexagonal screw in
the expansion valve upper part, if the pressure is
not within the indicated range (between 2 and
2,3 bar).
$
$
i
In case of replacement, use the right o-rings and
perform the calibration as instruction above.

Pressure switch P2

Expansion valve

Clockwise to increase the value.
Counterclockwise to decrease the value.
1 689 975 253
en
is displayed.
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2021-01-26