Grundfos UNOLIFT, Installation And Operating Instructions Manual

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12. Fault finding the product
WARNING
Biological hazard
Death or serious personal injury
‐
Wear protective gloves, close the
isolating valves and drain the tank
before you start any work on the tank.
For faults indicated by alarms and related to the
controller, see the installation and operating
instructions of the controller.
For faults related to the pumps, see the installation
and operating instructions of the pumps.
12.1 The pump does not start.
Cause Remedy
The float switch is blocked in low position. 1. Make sure that the float switch can move freely.
2. It may be necessary to adjust the cable length. See
section Setting the start levels.
The pump cable is defective. Repair or replace the cable.
Related information
7.1 Setting the start levels
12.2 The pump does not stop.
Cause Remedy
The float switch is blocked in high position. 1. Make sure that the float switch can move freely.
2. It may be necessary to adjust the cable length. See
section Setting the start levels.
Related information
7.1 Setting the start levels
12.3 The pump starts and stops randomly.
Cause Remedy
The float switch is not set properly. Adjust the cable length of the float switch. See section
Setting the start levels.
The level sensor tube is not fixed properly in the tank
and is moving up as the liquid rises. The sensor
receives wrong signals. Fix the tube to the tank. See fig. 13.
The float switch cannot move freely because the
pump has moved. Position the pump according to fig. Correct position of
UNILIFT CC and KP pumps or Correct position of
UNILIFT APB pumps.
Related information
3.12 Installing the pump
3.13.2 Assembling the pump connecting pipes
7.1 Setting the start levels
12.4 The tank is not emptying although the pump is running.
Cause Remedy
There is an airlock in the pump impeller. The pump
cannot build up pressure. Drill a hole of maximum 6 mm in the connecting pipes in
the tank. The air is pushed out when the pump starts,
and the pump builds up pressure. The pressure loss
due to the hole is negligible.
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English (GB)