Protection And Control Functions; Pump Controllers; Level Controllers - Grundfos SE1 50 Installation And Operating Instructions Manual

7. Protection and control functions

7.1 Pump controllers

The pumps can be controlled via the Grundfos
controllers, LC, LCD 107, LC, LCD 108, LC, LCD 110
and DC, DCD.
Pumps with a sensor are supplied together with an
IO 113 which can receive signals from the following
transmitters:
• water-in-oil-sensor (WIO sensor) in the pump
• moisture sensor in the motor
• temperature sensor in the stator windings
• winding resistance sensor in the motor.
For further information, see installation and
operating instructions for the specific sensor.

7.2 Level controllers

The following LC, LCD, DC and DCD pump
controllers are available for level control:
LC controllers are for one-pump installations and
LCD controllers are for two-pump installations.
• LC 107 and LCD 107 with air bells
• LC 108 and LCD 108 with float switches
• LC 110 and LCD 110 with electrodes
• DC for one-pump installations
• DCD for two-pump installations.
In the following description, "level switches" can be
air bells, float switches or electrodes, depending on
the pump controller selected.
7.2.1 LC, LCD
The LC controller is fitted with two or three level
switches: One for start and the other for stop of the
pump. The third level switch, which is optional, is for
high-level alarm.
The LCD controller is fitted with three or four level
switches: One for common stop and two for start of
the pumps. The fourth level switch, which is optional,
is for high-level alarm.
When installing the level switches, observe the
following points:
• To prevent air intake, dry running and vibrations,
install the stop level switch in such a way that the
pump is stopped before the liquid level falls
below the upper edge of the clamp of the pump.
See fig. 14, minimum mark.
• In pits with one pump, install the start level switch
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
bottom inlet pipe to the pit. See fig. 14, maximum
mark.
• In pits with two pumps, the start level switch for
pump number two must start the pump before the
liquid level reaches the bottom inlet pipe to the
pit, see fig. 14, maximum mark. The start level
switch for pump number one must start this pump
correspondingly earlier.
• If used, 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 bottom inlet pipe to
the pit. See fig. 14, maximum mark.
For further information, see the installation and
operating instructions for the pump controller
selected.
Float switches used in potentially
explosive environments must be approved
for this application. They must be
connected to the Grundfos LC, LCD 108
pump controller via the intrinsically safe
LC-Ex4 barrier to ensure a safe circuit.
7.2.2 DC, DCD
The Dedicated Controls system consists of a CU 362
control unit connected to one or two IO 351 modules.
An optional IO 113 sensor can be connected to each
pump.
CU 362 is the 'brain' of the system and must be
incorporated in all installations. The units in the
system can be combined in different ways according
to the user's needs.
Dedicated Controls control the pumps by means of
power contactors and IO 351 modules. Power
contactors, cable and other high-voltage
components must be positioned as far away as
possible from the control system and the signal
cables.
Dedicated Controls are operated via a user-friendly
control panel on the CU 362 or via a PC. Wireless
remote control is available throughout the world,
using a PC or mobile phone. Dedicated Controls can
be integrated into a user's existing SCADA system.
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