English (GB)
10
5. Systems with 3 float switches
Description (see also page
or
The pump is controlled by the liquid level in the pit.
• The float switch, pos. 2, starts the pump.
• The float switch, pos. 1, stops the pump. It is possible to set a
"stop delay" which delays the stop of the pump.
• The top float switch, pos. 3, activates the high-level alarm.
5.1 Electrical connection
3 float switches, pages
and
Fig.
on page
.
The figures show all electrical connections required to connect
the LC 108 for
direct-on-line starting, 3 float switches
.
Fig.
on page
.
The figure shows all electrical connections required to connect
the LC 108 for
start-delta starting, 3 float switches.
The operating voltage and frequency are marked on the controller
nameplate. Make sure that the controller is suitable for the
electricity supply on which it will be used.
All cables/wires must be fitted through the Pg cable entries and
gaskets (IP65).
Maximum back-up fuse is stated on the controller nameplate.
If required according to local regulations, an external mains
switch must be installed.
Single-phase motors must be connected to an external operating
capacitor and in certain cases also to a starting capacitor.
Further details can be found in the installation and operating
instructions for the pump in question.
The float switches must be connected as NO contacts, i.e. brown
and black leads, when float switches, Grundfos product number
96003332 or 96003695, are used.
Key to the symbols in fig.
on page
and fig.
:
5.2 Setting
3 float switches, pages
.
The CU 211 module has a 10-pole DIP switch in the bottom right
corner, see fig.
The DIP switch setting offers the following possibilities:
• selection of starting delay and automatic test run (switch 4),
• setting of stop delay (switches 5, 6 and 7),
• selection of automatic alarm resetting (switch 9),
• selection of automatic restarting (switch 10).
Fig. 8
Set the DIP switch as shown in fig.
.
Each individual switch (1 to 10) of the DIP switch can be set to
position OFF or ON.
Warning
Before starting any work on pumps used to pump
liquids which could be constituted as being
hazardous to health, thorough cleaning/venting of
pumps, pits, etc. must be carried out according to
local regulations.
Before making any connections in the LC 108 or
work on pumps, pits, etc., it must be ensured that the
electricity supply has been switched off and that it
cannot be accidentally switched on.
Warning
Before starting work on the system, switch off the
supply voltage and lock the mains switch in position
0.
Any external voltage connected to the system must
be switched off before work is started.
Warning
The LC 108 must be connected in accordance with
the rules and standards in force for the application in
question.
Caution
If the PTC resistance/thermal switch of the motor is
connected, the factory-fitted short-circuit jumper
must be removed (terminals T11-T21).
Warning
Float switches or electrodes placed in an explosion
hazard area must be connected via an EEx barrier,
e.g. Grundfos number 96440300. The EEx barrier
must not be installed in the explosion hazard area.
Equipment used in explosion hazard areas must in
each individual case have been approved for this
particular application. Furthermore, the cables into
the explosion hazard area must be laid in
accordance with local regulations.
Note
Float switches of the same type as Grundfos product
number 96003332 or 96003695, i.e. float switches
with gold-plated contacts suitable for low voltages
and currents (40 V / 100 mA), must be used. All EEx-
approved float switches are also suitable.
Pos. Description
Terminal number
1
Float switch for stop of pump.
11-12
2
Float switch for start of pump.
21-22
3
Float switch for high-level alarm.
31-32
Caution
The controller must be off circuit to ensure the
correct configuration during start-up after change of
the DIP switch setting.
T
M
04
2
3
4
1
23
08
Note
The DIP switch must not be set to other switch
combinations than those described in this section.
