General Service Information; Replacement Of Level Sensor - Grundfos LCD 109 Handbuch

6. General service information

Before dismantling
Warning
Before starting service work, switch off
power supply to lifting station and level
controller. Make sure the power cannot
be accidentally switched on.
1. Close the inlet isolating valve.
2. Drain the discharge pipe by tightening the drain
screw of the collecting tank non-return valve;
this will cause the internal flap of the non-return
valve to be lifted up in order to let the water in the
discharge pipe excape. This is only necessary if
there is no isolating valve in the discharge pipe.
3. Flush the lifting station thoroughly with clean
water. Rinse the parts when dismantling the
lifting station.
After assembly
1. Open all isolating valves.
2. Check all functions by filling the tank with water
and starting the pump.

7. Replacement of level sensor

Warning
Before replacing the old pressure
sensor make sure that the controller is
switched off and disconnected from
mains.
Jumpers JP1
Fig. 5
The piezoresistive sensor is factory-set for
Multilift MSS, M or MD having a pressure tube length
of 318 mm. This can be seen from the position of the
jumpers JP1 in fig. 6.
6
● ●
● ●
● ●
Jumper setting for MSS, M or MD
Fig. 6
Proceed as follows
1. Find a suitable spot on the wall to place the level
converter. Make sure to mount it safely.
2. Open the LC 109 or LCD 109 controller and
locate the connector block for the sensor.
See pos. 2 in fig. 7.
Connector block location in LC 109
Fig. 7
3. Disconnect the sensor cable (white cord).
4. Loosen the PG cable entry and remove the old
sensor cable.
5. Remove the old level sensor with tube from the
tank.
6. Install the new pressure tube in the tank.