Installation And Operating Instructions; Systems With 2 Levels (3 Electrodes); Electrical Connection - Grundfos LC 110 Montage- Und Betriebsanleitung

Figure 2 shows the terminals listed under positions 2 and 3.
Fig. 2
Key to the symbols in figs. 1
Pos. Description
1 Module CU 213.
Terminal block for level inputs
2
(11-12, 22, 32 and 42).
Terminal block with:
• input for the motor PTC resistor/thermal switch
(T11-T21),
• input for the motor thermal switch (T11-T21),
3
• output for external alarm device for high-level alarm
(H-NC, H-COM, H-NO) (only certain variants),
• output for external alarm device for common alarm
(G-NC, G-COM, G-NO).
Motor protection relay (contacts and thermal relay
4
fitted).
5 Terminal block for electricity supply.
Fuse holders for control circuit fuses
6
(1 to 3 depending on voltage/current variant).
9 Pg cable entries.
10 Earth bar ( ).
PE
If the distance between the controller and pit
exceeds 20 metres, it is not advisable to use
electrodes as problems with the signal values sent
Note
back to the controller may arise.
In such cases, it is recommended to use float
switches.
Cables of up to 100 metres can be connected
Note
between the controller and the float switches.
6
and 2:

4. Systems with 2 levels (3 electrodes)

Description (see also page 261):
The pump is controlled by the liquid level in the pit.
• The pump is started when the electrode, pos. 1, registers
liquid.
• When the electrode, pos. 1, no longer registers liquid, the stop
delay (can be set) is activated. After expiration of the stop
delay, the pump is stopped.
• The top electrode, pos. 2, activates the high-level alarm.
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 110 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.

4.1 Electrical connection

Systems with 2 levels (3 electrodes), page 261.
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.
Figure 1 on page 261 shows all electrical connections required to
connect the LC 110 for 2 levels (3 electrodes).
Warning
The LC 110 must be connected in accordance with
the rules and standards in force for the application in
question.
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.
If the motor PTC resistor/thermal switch is
connected, the factory-fitted short-circuit jumper
must be removed (terminals T11-T21). For correct
Caution
installation of PTC resistor/thermal switch, see the
installation and operating instructions of the pump.
Key to the symbols in fig. 1 on page 261:
Pos. Description
R Reference electrode.
1 Electrode for start/stop of pump.
2 Electrode for high-level alarm.
Terminal
number
11
12
32