Motor Protection And Activation Types; Operation With Variable Frequency Drives; Commissioning - Wilo Rexa PRO Notice De Montage Et De Mise En Service

COMMISSIONING

Motor compartment monitor
• The motor compartment monitor must be con-
nected via an evaluation relay. We recommend the
"NIV 101/A" relay for this. The threshold is 30 kΩ.
When the threshold is reached, the pump must
switch off.
Connecting the pencil electrode (available as an
option) for sealing chamber control
• When used outside potentially explosive areas,
the pencil electrode can be connected via the
NIV 101/A relay. The threshold is 30 kΩ. When the
threshold is reached, a warning must be given or the
unit switched off.
CAUTION!
If there is only a warning, the pump could be
irreparably damaged by water ingress. We rec-
ommend always switching the pump off!

5.6. Motor protection and activation types

5.6.1. Motor protection
The minimum requirement for motors with a free
cable end is a thermal relay/motor protection switch
with temperature compensation, differential trig-
gering, and an anti-reactivation device, in accor-
dance with national regulations.
If the pump is connected to electrical systems in
which faults frequently occur, we recommend in-
stalling additional protective devices, to be provided
by the customer (e.g. relays for overvoltage, under-
voltage, or phase failure; lightning protection, etc.).
We also recommend installing a residual current
device (RCD).
Local and national regulations must be observed
when connecting the pump.
5.6.2. Activation types
Direct activation
At full load, the motor protection should be set to
the rated current shown on the rating plate. At par-
tial load, we recommend that the motor protection
be set 5% above the current measured at the duty
point.
Soft start activation
• At full load, the motor protection should be set to
the rated current at the duty point. At partial load,
we recommend that the motor protection be set
5% above the current measured at the duty point.
• The current consumption must be below the rated
current throughout the entire operation.
• Due to the upstream motor protection, starting or
stopping should be completed within 30 seconds.
Installation and operating instructions Wilo-Rexa PRO
• To avoid power dissipation during operation, bypass
the electronic starter (soft start) once normal oper-
ation is reached.
Pumps with a plug
At full load, the motor protection should be set to
the rated current shown on the rating plate. At par-
tial load, we recommend that the motor protection
be set 5% above the current measured at the duty
point.
Plugs are not immersion-proof. Note the protec-
tion class (IP). The socket must be installed where
it will not be submersed.

5.6.3. Operation with variable frequency drives

Operation on a variable frequency drive is possible.
Note the information about this in the appendix.
6. Commissioning
The "Commissioning" section contains all the im-
portant instructions for the operating personnel for
starting up and operating the pump.
The following conditions must be adhered to and
monitored:
• Type of installation
• Operating mode
• Minimum water submersion/max. immersion depth
These general conditions must also be checked
after a long period without operation, and any
defects detected must be repaired!
Always keep this manual either by the pump or in a
place specially reserved for it, where it is accessible
for the entire operating personnel at all times.
In order to prevent damage or serious injury when
commissioning the pump, the following points must
be observed:
• Commissioning of the pump may only be carried out
by qualified and trained personnel in accordance
with the safety instructions.
• All persons working on or with the pump must have
received, read, and understood this operating and
maintenance manual.
• All safety devices and emergency cut-outs must be
connected and checked to ensure that they work
properly.
• Electrical and mechanical adjustments must be
made by qualified personnel.
• The pump is suitable for use under the specified
operating conditions.
• In general, people should be kept out of the working
area of the pump. No persons should be allowed in
the working area during startup or operation.
• When working in sumps, a second person must be
present. Adequate ventilation must be ensured if
there is danger of toxic gases forming.
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