6.4.10 Control of the automatic wiper
The wiper is driven by an electric motor that has the following
inputs and outputs:
n
Motor, clockwise rotation
n
Motor, anticlockwise rotation
n
Pulse output
n
Motor, fault
There is also a magnetic proximity switch to monitor the start posi‐
tion of the wiper.
A wiper cycle consists of the forward motion of the wiper element
from the start position up to the end of the UV lamp. The end posi‐
tion on the UV lamp is recognised by counting the motor rotations.
Then the wiper element returns to the start position. The start posi‐
tion is monitored using the proximity switch.
A wiper cycle can be triggered manually or by the control.
The wiper cycle is superimposed over the various operating sta‐
tuses. Thus, for example, the UV system continues to be moni‐
tored for faults, pause etc. Should the control switch off the UV
system, then the wiper cycle ends and the wiper is moved to the
start position once the UV system has been switched off. A fault
can only be acknowledged or the UV system restarted following
the end of the wiper cycle.
To avoid error messages due to shading of the UV sensor by the
wiper elements, the status of the warning and safety threshold is
frozen at the status prior to the start of the wiper cycle during the
wiper cycle. Each time the supply voltage is switched on, the con‐
trol checks whether the wiper is in the start position. If not, an
attempt is made to reach the start position. Only then does the UV
system move to
[Off] status.
If a wiper fault is detected, then an error message is displayed on
the display instead of the wiper display and the display is backlit in
red. The
‘Fault’ output opens. In the event of a fault of the wiper, if
the time for the gaps between the wiping cycles is set to 0, the
wiper is deactivated and the UV system continues its operation.
The UV system is in
‘Warning’ status and the display is backlit in
yellow. Further wiping cycles are no longer triggered, otherwise the
UV system continues running as normal. The fault can only be
acknowledged if the UV system is switched off.
Operation without wiper
Continuous operation of the UV system without a
wiper is not permitted. The cause of the wiper fault
has to be rapidly eliminated to ensure reliable dis‐
infection of the water.
General information about wiper con‐
trol
Control
34
