Removal And Fitting Of Cable Guard; Fitting Of Submersible Drop Cable; Riser Pipe; Maximum Installation Depth Below Water Level - Grundfos SP Serie Montage- Und Betriebsanleitung

6.2 Removal and fitting of cable guard

For removal and fitting of cable guard(s), see pages 159 and 160.
If the cable guard is screwed on to the pump, such as the SP 215
and sleeved pumps, the cable guard should be removed and
fitted by means of screws.
Make sure that the pump chambers are aligned
Caution
when the cable guard has been fitted.

6.3 Fitting of submersible drop cable

6.3.1 Grundfos submersible motors
Before fitting the submersible drop cable to the motor, make sure
that the cable socket is clean and dry.
To facilitate the fitting of the cable, lubricate the rubber parts of
the cable plug with non-conducting silicone paste.
Tighten the screws holding the cable to the torques stated:
MS 402: 2.0 Nm.
MS 4000: 2.0 Nm.
MS6: 5.5 Nm.
MS 6000: 4.0-5.0 Nm.
MMS 6000: 10 Nm.
MMS 8000: 18 Nm.
MMS 10000: 18 Nm.
MMS 12000: 15 Nm.

6.4 Riser pipe

If a tool, e.g. a chain pipe wrench, is used when the riser pipe is
fitted to the pump, the pump must only be gripped by the pump
discharge chamber.
The threaded joints on the riser pipe must all be well cut and fit
together to ensure that they do not work loose when subjected to
torque reaction caused by the starting and stopping of the pump.
The thread on the first section of the riser pipe which is to be
screwed into the pump should not be longer than the threads in
the pump.
If noise may be transmitted to the building through the pipework,
it is advisable to use plastic pipes.
Plastic pipes are recommended for 4" pumps
Note
only.
When plastic pipes are used, the pump should be secured by an
unloaded straining wire to be fastened to the discharge chamber
of the pump, see fig. 20.
Fig. 20 Fixing the straining wire
When connecting plastic pipes, a compression coupling should
be used between the pump and the first pipe section.
Where flanged pipes are used, the flanges should be slotted to
take the submersible drop cable and a water indicator hose,
if fitted.

6.5 Maximum installation depth below water level

Grundfos MS 402: 150 m.
Grundfos MS 4000: 600 m.
Grundfos MS6: 600 m.
Grundfos MS 6000: 600 m.
Grundfos MMS: 250 m.
Franklin motors: 350 m.

6.6 Cable fitting

Cable clips must be fitted every 3 metres to fix the submersible
drop cable and the straining wire, if fitted, to the riser pipe of the
pump.
Grundfos supplies cable clip sets on request. The set consists of
a 1.5 mm thick rubber band and 16 buttons.
Cable fitting: Cut off the rubber band so that the piece with no
slit becomes as long as possible.
Insert a button in the first slit.
Position the wire alongside the submersible drop cable, fig. 21.
Fig. 21 Fitting the cable clips
Wind the band once around the wire and the cable.
Then wind it tightly at least twice around the pipe, wire and the
cable.
Push the slit over the button and then cut off the band.
Where large cable cross-sections are used, it will be necessary to
wind the band several times.
Where plastic pipes are used, some slackness must be left
between each cable clip as plastic pipes expand when loaded.
When flanged pipes are used, the cable clips should be fitted
above and below each joint.

6.7 Lowering the pump

It is recommended to check the borehole by means of an inside
calliper before lowering the pump to ensure unobstructed
passage.
Lower the pump carefully into the borehole, taking care not to
damage the motor cable and the submersible drop cable.
Do not lower or lift the pump by means of the
Caution
motor cable.

6.8 Installation depth

The dynamic water level should always be above the suction
interconnector of the pump, see section 4.2 Positional
requirements and fig. 22.
Minimum inlet pressure is indicated in the NPSH curve for the
pump.
The minimum safety margin should be 1 metre head.
It is recommended to install the pump so that the motor part is
above the well screen in order to ensure optimum cooling, see
section 4.4 Liquid temperatures/cooling.
When the pump has been installed to the required depth, the
installation should be finished by means of a borehole seal.
Slacken the straining wire so that it becomes unloaded and lock it
to the borehole seal by means of wire locks.
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