Adjustment Of Cable Length For Float Switch; Electrical Connection; Operation; Self-Venting - Grundfos Unilift CC 5 Manual Del Usuario

7.4 Adjustment of cable length for float
switch
The difference in level between start and stop can be
adjusted by changing the free cable length between
the float switch and the pump handle.
• An increased free cable length results in fewer
starts/stops and a large difference in level.
• A reduced free cable length results in more
starts/stops and a small difference in level.
In order that the float switch can start and stop the
pump, the free cable length must be min. 100 mm
and max. 200 mm.
Start
Stop
Fig. 9 Start/stop levels at min. and max. cable
lengths
Cable length (L)
min. 100 mm
Pump type
Start
[mm]
Unilift CC 5 350
Unilift CC 7 350
Unilift CC 9 385

7.5 Electrical connection

Supply voltage: 1 x 220-240 V, 50 Hz.
The electrical connection must be carried out in
accordance with local regulations.
Check that the mains voltage and frequency
correspond to the values stated on the pump
nameplate.
Warning
As a precaution, the pump must be
connected to a socket with earth
connection.
It is recommended to fit the permanent
installation with an earth leakage
circuit breaker (ELCB) with a tripping
current < 30 mA.
L
Cable length (L)
max. 200 mm
Stop Start Stop
[mm] [mm] [mm]
115 400 55
115 400 55
150 435 90

8. Operation

8.1 Self-venting

A vent valve is built into the pump handle. The valve
allows air to escape from the pump in case the free
air flow through the discharge pipe is blocked.
Once the pump is vented, the valve normally closes.
If the pump sucks air or water with a high air content,
the valve may leak a mixture of air and water. This is
no fault but a natural consequence of the opening
and closing of the valve.
Fig. 10 Self-venting

8.2 Manual operation

The pump is started and stopped by an external
switch.
To eliminate the risk of dry running, the water level
should be checked regularly during operation.
This can for instance be done by an external level
controller.
In order that the pump can self-prime when started,
the water level must be at least 25 mm.
When the pump sucks water, it can pump down to
20 mm water level.
For pumping to low level, see section
low water level.

8.3 Automatic operation

During automatic operation, the pump with float
switch will start and stop, depending on the water
level and the float switch cable length.
Forced operation of pump with float switch
If the pump is used to drain water levels below the
stop level of the float switch, the float switch can be
kept in a higher position by fixing it to the discharge
pipe.
During forced operation, the water level should be
checked regularly to prevent dry running.
8.4 Pumping to
9