Grundfos SE1 50 Notice D'installation Et De Fonctionnement page 18

6. Electrical connection
DANGER
Electric shock
Death or serious personal injury
‐
Connect the pump to an external
mains switch which ensures all-
pole disconnection with a contact
separation according to National
Electrical Code and all local codes.
‐
It must be possible to lock the
mains switch in position 0. Type
and requirements as specified in
National Electrical Code and all
local codes.
‐
The electrical connection must be
carried out in accordance with local
regulations.
The pumps must be connected to a
controller with a motor protection relay
with IEC trip class 10 or 15 or NEMA
equivalent.
Power supply for motor-protection
circuit must be low voltage, Class 2.
6.1 Protection and control functions
6.1.1 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 customization for single- and dual-pump
versions.
• Dedicated Controls (DC): high-end cabinet
solution for multi-pump versions up to 6
pumps.
In the following description, "level switches" can
be air bells, float switches, or electrodes
depending on the selected pump controller.
Depending on the security 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).
An analog level transmitter can be used and all
levels can be customized. Level switches can be
used with a level transmitter (one for dry and one
for high level).
When installing the level switches, observe the
following:
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• 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 be started before the liquid level
reaches the bottom of the inlet pipe.
• Always install the high-level alarm switch
about 3.93 inches (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, see the installation and
operating instructions for the selected pump
controller.
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. The pump must be stopped
when the liquid level reaches the upper
edge of the clamp.
Float switches used in potentially
explosive environments must be
approved for this application. They
must be connected to the Grundfos LC
231 or LC 241 level controller by an
FM
intrinsically safe barrier to ensure a
safe circuit.
In potentially explosive environments,
the anti-seizing function must be
disabled on the pump controllers.
6.1.2 Switches and sensors
Every explosion-proof pump is assembled with a
WIO sensor.
Pumps for hazardous locations must
be connected to a control box with a
FM
motor protection relay with IEC trip
class 10.