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English (GB)

13

10.3 Float switches

If float switches have been selected, they can be fitted on a tube 
which can be lifted out of the pit. This ensures easy adjustment of 
float switches.

Fig. 22 Adjustment of float switches

The pit inlet must not be located within the area shown in fig. 23, 
as it will disturb the function of float switches.

Fig. 23 Location of inlet

10.4 Rod electrodes

If rod electrodes are used for level measurement, note that the 
rods come in standard length (1 m). When they are installed, their 
length must therefore be adjusted so that they are activated at 
the correct levels.

If possible, bend the rods away from each other so that paper and 
similar items cannot get stuck between the rods and disturb the 
signal.

When they have been shortened, 10 to 15 mm of the lower end of 
the rods must be stripped.

The rods come with 10 metres of cable.

Fig. 24 Rod electrodes in a pit with one pump

Fig. 25 Rod electrodes in a pit with two pumps

10.5 Air bells

Air bells are pulse generators for the pressure switches of the 
controller and function by means of pneumatic pressure changes. 
The pressure changes when the liquid level in a pickup changes. 
The air bells are connected to the pressure switches of the 
controller by means of hoses.

Fig. 26 Air bells in a pit with one pump

10.6 Pressure transducer

If a pressure transducer is used, it should be installed in a riser 
pipe in order to prevent contamination and deposits.

10.7 Other types of level control equipment

See the installation and operating instructions of the equipment.

Note

Note that the bottom float switch (stop) must stop 
the pump before the level in the pit falls below 
the minimum level of the pump. See the 
installation and operating instructions of the 
pump.

TM

0

2

 8

960

 1

204

A

Min. 300 mm

B

50 to 100 mm

C

Deactivation range 110 mm

Caution

Distance B must not be too big as otherwise the 
float switch may get stuck in other parts of the 
installation.

TM

0

2

 8

961

 1

204

A

B

C

200

200

T

M

02

 8

9

62

 12

04

TM

02 89

63 120

4

TM

0

1

 9

345

 2

404

Alarm: 32
Start: 22

The stop level 
depends on the 
pump type.

Common: 11

Alarm: 42

Start

2

: 32

The stop level 
depends on the 
pump type.

Common: 11

Start

1

: 22

CU 211

CU 211

Содержание PUST04

Страница 1: ...t be led into the pit See also the installation and operating instructions of the pump 3 1 4 Density Maximum 1 1 tons m3 1 Symbols used in this document 6 2 General description 6 3 Applications 6 3 1...

Страница 2: ...inless steel AISI 304 Prepared for pump type KP Unilift KP Unilift CC AP35 Unilift AP12 40 Unilift AP35 AP50 Unilift AP12 50 Unilift AP50 APB Unilift AP35B Unilift AP50B DPEF DP 0 6 1 5 kW EF DPSE DP...

Страница 3: ...B 8 TM02 9364 2404 TM02 9363 2404 Fig 3 Pit with free standing pump Fig 4 Pit with pump on auto coupling TM02 9366 2404 TM02 9365 2404 Fig 5 Pit with pump on wall mounted auto coupling Fig 6 Pit with...

Страница 4: ...viest standard pit weighing approximately 1000 kg 7 Sizing The pit volume depends on the wastewater flow rate and the pump performance If the liquid in the pit is static during long periods sediments...

Страница 5: ...The backfill must meet the same requirements as those for the bedding layer The backfilling must be carried out so that the pit is not damaged or deformed The backfill must be compacted in layers of m...

Страница 6: ...cutting edge of the hole saw by at least 23 mm The position of the hole is not an issue See fig 17 Fig 17 Drillilng from the inside Caution If the hole for the pit is drilled pay special attention to...

Страница 7: ...he start level switch should be installed in such a way that the pump is started at the required level however the pump must always be started before the liquid level reaches the lower edge of the bot...

Страница 8: ...lse generators for the pressure switches of the controller and function by means of pneumatic pressure changes The pressure changes when the liquid level in a pickup changes The air bells are connecte...

Страница 9: ...oduct or parts of it must be disposed of in an environmentally sound way 1 Use the public or private waste collection service 2 If this is not possible contact the nearest Grundfos company or service...

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