4 | Transport and installation
OPM BWT PERMAQ® Pico Rev. 2.0 EN
EN
22
•
Do not operate the external contact inputs (e.g. start and stop contacts) with an external
voltage (dry contacts). The multi-cable connection for the external contacts is located at
the bottom of the control cabinet.
•
Note that the cable harnesses are always routed through the flexible protective tubes. This
applies especially to the cables of the external level sensors and the control cables for
alarm contacts.
•
Never cover the air inlet opening for the control cabinet fan.
Fig.
19: Air inlet opening
Performing the electrical installation
ü
Refer to the notes on the electrical installation.
1) Route the cabling in accordance with the valid circuit diagram for the device type.
Operating the device
External contacts are required to operate the device. Both digital and analogue signals can be
used for operation. Usually, these sensors and level sensors are installed in a permeate tank
downstream of the RO device.
Digital contacts:
•
2 x float switches, either both NO or both NC
•
1 x single contact, NO or NC
Analogue contacts:
•
Ultrasonic probe (4–20 mA)
•
Pressure sensors (4–20 mA)
•
Other signals (4–20 mA)
Even when permeate consumption fluctuates, the switching frequency of the device is to be
reduced to a minimum. The two switching points for the permeate tank must be configured at
an interval which ensures that the device operates for at least 30 to 45 minutes following the
request. Operating times that are consistently insufficient (too many starts/stops) have a neg-
ative effect on the service life of the RO devices.
Switching points of a purified water tank
The figure below shows the physical arrangement of possible switching points in the purified
water tank. The RO device can be controlled using both analogue and digital signals based on
the filling level. The filling level percentage specification should only be considered as a rough
indication and can be adjusted to the local conditions at any time.
Once a request signal is present, it is shown on the display. The device then automatically
switches to production mode once the multiple start-up steps in the defined start-up se-
quence are complete.
