5.2 Sensors
The thermal switch in circuit 1 (T1-T3) and circuit 2
(T1-T2) breaks the circuit at an approximate 140 °C
winding temperature. This thermal switch must
always be connected.
AP80-100
Thermal protection
Enclosed in motor winding, requires outside control
through the signal wires of the power cable.
Oil chamber seal probe
Requires outside control through the signal wires of
the power cable.
5.3 CU 100 control unit
CU 100 incorporates a motor-protective circuit
breaker and is available with level switch and cable.
5.4 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.
5.4.1 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.
6. Startup
Before starting the product:
•
Make sure that the fuses have been
removed.
•
Make sure that all protective
equipment has been connected
correctly.
•
Check the oil level.
•
Test the insulation resistance.
CAUTION
Crushing of hands
Minor or moderate personal injury
‐
Do not put your hands or any tool into
the pump inlet or outlet after the pump
has been connected to the power
supply, unless the pump has been
switched off by removing the fuses or
switching off the main switch.
‐
Make sure that the power supply
cannot be switched on unintentionally.
CAUTION
Biological hazard
Minor or moderate personal injury
‐
Make sure to seal the pump outlet
properly when fitting the outlet pipe,
otherwise water might spray out.
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English (GB)
