Cu 100 Control Unit; Level Controllers - Grundfos AP40-70 Montage- Und Betriebsanleitung

DANGER
Electric shock
Death or serious personal injury
‐
If the power cable is damaged, it must
be replaced by the manufacturer, his
service agent or a similarly qualified
person.
Set the motor-protective circuit breaker to
the rated current of the pump. The rated
current is stated on the nameplate.
Make sure that the pump is connected in
accordance with the instructions of this
booklet.
The supply voltage and frequency are marked on the
pump nameplate. Make sure the power supply at the
installation site is suitable for the pump motor.
All pumps are supplied with 10 m cable and a free
cable end.
DANGER
Electric shock
Death or serious personal injury
‐
Before the first startup, check the cable
for visible defects to avoid short
circuits.
The pumps must be connected to one of the
following:
• a control unit with motor-protective circuit
breaker, such as Grundfos CU 100
• Grundfos LC 231 or 241 pump controller.
Pumps cannot be operated with frequency
converter.

5.1 CU 100 control unit

CU 100 incorporates a motor-protective circuit
breaker and is available with level switch and cable.

5.2 Level controllers

The liquid level can be controlled by the Grundfos LC
level controllers.
Suitable level controllers:
• LC 231: compact solution with certified motor
protection for single- and dual-pump versions.
• LC 241: cabinet solution offering modularity and
customisation for single- and dual-pump
versions.
In the following description, "level switches" can be air
bells, float switches or electrodes depending on the
selected pump controller.
Depending on the security levels and the number of
pumps, level switches can be used in the following
setups:
• Dry run (optional)
• Stop
• Start pump 1 (single-pump version)
• Start pump 2 (dual-pump version)
• High level (optional)
Analogue level transmitters can be used, and all
levels can be customised. Level switches can be
used with level transmitters, for dry-run protection and
high level alarm.
The pump must not run dry. Install an
additional level switch to ensure that the
pump is stopped in case the stop level
switch is not operating.
5.2.1 Installing level switches
When installing the level switches, observe the
following points:
• To prevent air intake and vibrations, install the
stop level switch, so the pump is stopped before
the liquid level is lowered to the middle of the
motor housing.
• Install the start level switch, so the pump is
started at the required level. The pump must
always start before the liquid level reaches the
bottom inlet pipe.
• Always install the high-level alarm switch about
10 cm above the start level switch. However, the
alarm must always be given before the liquid
level reaches the inlet pipe.
For further settings and information, see the
installation and operating instructions for the selected
level controllers.
11