Storch LP 540 flex Handbuch Seite 147

The device will not Pressure sensor
switch on
Pressure regulator button (poten-
tiometer)
Repairing the pressure regulator
Motor controller card diagnostics
Before performing maintenance work on the controller card, relieve the pressure and unplug the mains plug on the
spraying unit. Read the depressurisation section on page 7 for details.
NOTE:
Keep a new pressure sensor handy for this test.
INSTRUCTIONS:
The spraying device must never build up fluid pressure if no pressure sensor is installed. Keep the ventilation/pressure
relief valve open while using the test pressure sensor.
1. Remove the four screws and the cover.
2. Turn the ON/OFF switch to the ON position.
Fit a different pressure sensor on the controller card.
If the device starts, the old sensor is defective. If no
replacement sensor is available, you can use a multime-
ter to check the resistance on the red and black wires
of the sensor (do not forget to unplug the mains plug).
This should be 1.5-3.5 kΩ. Defective sensors typically
fail to detect DC voltage (open).
If the sensor passes all the tests, see pressure regula-
ting button (potentiometer).
Fit a different potentiometer on the control panel. If the
device starts, the old potentiometer is defective. If no
replacement potentiometer is available, you can unplug
the potentiometer cable (with the device switched off)
from the controller card and check the resistance on the
red and black wires of the potentiometer (do not for-
get to unplug the mains plug). This should be 8-12 kΩ.
If the value is higher than this, you must replace the
potentiometer.
If DC voltage is present on the motor brushes, and both
the sensor and the pressure regulating button are wor-
king, replace the pressure regulator unit.
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