Grundfos CH 12, Installation And Operating Instructions Manual

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2. Installation
2.1 Pump location
The pump should be installed so that the suction
pipe is as short and the suction lift as small as possi-
ble.
The pump should be sited in a well ventilated but
frost-free position, see section
5.1 Frost protection .
It may be sited outside, but it should be protected
from the elements by means of a suitable cover.
The pump may be installed in one of the positions
shown in fig. 1.
Fig. 1
2.2 Position of terminal box
The terminal box can be turned to any one of the po-
sitions shown in fig. 2 before the pump is installed.
Fig. 2
To change the position of the terminal box:
1. Remove the four screws which, from the motor
side, are screwed into the discharge chamber.
2. Turn the stator housing to the required position.
3. Replace the screws and tighten securely.
2.3 Pipework
The pipes should be fitted so that any tension
caused by variations in temperature does not affect
the pump.
2.3.1 Suction pipe
If the pump is to draw liquid from a level lower than
the pump suction port, a foot/non-return valve must
be fitted to the end of the suction pipe, below the
lowest liquid level, since the pump is not self-prim-
ing.
The suction pipe is connected to the pump suction
port S, fig. 3.
Fig. 3
When the suction pipe is longer than 10 metres or
the suction lift is greater than 4 metres, the diameter
of the suction pipe must be larger than that of the
pump suction port.
Every joint of the suction pipe must be completely
tight.
If a hose is used as suction pipe, it must be non-col-
lapsible. A strainer is recommended in cases where
solids could enter the suction pipe and block the
pump.
2.3.2 Discharge pipe
The discharge pipe is connected to the discharge
port T, fig. 3.
The discharge pipe should be at least the same di-
ameter as the discharge port of the pump, to mini-
mize pressure drop, high flow velocities and noise.
2.3.3 Bypass
If there is any danger of the pump running against a
closed discharge valve, a minimum liquid flow
through the pump should be ensured by connecting
a bypass/a drain to the discharge pipe. The drain
can for instance be connected to a tank.
A minimum flow rate equal to 10% of the flow rate at
maximum efficiency is needed at all times. Flow rate
and head at maximum efficiency are stated on the
pump nameplate.
2.4 Installation examples
The pump is suitable for a wide range of applica-
tions.
Some examples are shown on page 102.
TM
00
0
689
48
96
TM
00
06
90
51
92
T
S
TM
00 06
91 489
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