Electrical Connections - Wilo Economy MHIE 1-Serie Einbau- Und Betriebsanleitung

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- The diameter of the suction line is never permit-
ted to be smaller than the suction/pumping open-
ing of the pump.
- Limit the horizontal length of the suction line
and avoid all possible sources of pressure losses
(elbows, valves, neckings, etc.).
Possible damage to the pump!
ATTENTION!
In order to protect the pump against
fluid hammers, install the non-return
valve on the pressure side.

5.3 Electrical connections

DANGER! Risk of death!
Hazardous voltage due to the discharge of the
converter capacitors.
• Before any work on the converter, wait for 5
minutes after disconnecting the power supply.
• Check that all electrical connections and con-
tacts are de-energised.
• Check that the pressure connection terminals
have been allocated correctly.
• Check that the pump and the installation are
earthed correctly.
DANGER! Risk of property damage!
The converter cover must not be forced closed.
• Carefully place the connectors inside the con-
verter before closing.
Information about electrical connections
Unscrew the screws and remove the top cover
from the converter.
The electrical connections and testing must
be carried out by a licensed electrician and in
accordance with locally applicable standard
specifications.
In the frequency converter, the testing current
circuits are shielded from the performance
circuits with the aid of a simple insulation
(CEI664-1).
The installer must ensure that the external
testing current circuits (e.g.: pressure sensors,
external control of the setpoint...) are shielded
against any possible contact with people. If the
testing current circuits are to be connected to
the electric circuits corresponding to the safe-
ty specifications of the SELV (TBTS), then an
additional insulation must be installed in order
to comply with the SELV (TBTS) classification.
The electrical properties (frequency, voltage,
nominal current) of the motor frequency convert-
er are indicated on the name plate of the motor/
of the pump. A check is to be made as to whether
the motor frequency converter matches the cur-
rent supply network to which it is intended to be
attached.
The frequency converter is equipped with a motor
protection feature. Constant protection of the
motor and of the pump are ensured by a continu-
ous nominal/actual comparison of the current and
stored data.
In the event of excessively great resistance on
20
the part of the neutral conductor, a correspond-
ing protection device must be installed upstream
from the motor frequency converter.
As a basic rule, provide switch amplifiers with
fuses (Type GF) for the protection of the network
(see Figs. 1 + 2, Pos. 11).
If a residual-current-operated protection switch
needs to be installed for personnel protection,
then use a selective universal-current-sensitive
residual-current-operated protection switch
with VDE certificate!
Adjust the safety switch in accordance with the
data specified on the name plate of the fre-
quency converter.
Use connecting cables that meet applicable stan-
dards.
Earth the pump/installation in accordance with
regulations.
WILO SE 09/2021