Motor Protection And Activation Types - Wilo Sub TWU 3 Série Notice De Montage Et De Mise En Service

5.6.2 AC motor
The AC version is delivered with a factory-installed
start-up device. For connection to the mains, the
power supply cable is connected to the start-up device
(terminals L and N).
Electrical connections may only be made by a
qualified electrician!
5.6.3 Three-phase current motor
Three-phase current versions are delivered with free
cable ends. The system is connected to the mains
electricity supply by connecting it to the switch box.
Electrical connections may only be made by a
qualified electrician!
The wires of the connection cable are assigned as fol-
lows:
4-wire connection cable
Wire color
Black
Blue or gray
Brown
Green/yellow
5.6.4 Plug&Pump systems
When used for irrigating fields and gardens, a
30 mA earth leakage circuit breaker (RCD) must
be installed!
The required electrical connections (network and
motor side) are made at the factory on the fluid con-
trol or pressure switch. The system is equipped with a
safety plug, and is ready for connection.
5.6.5 Monitoring device connections
The Wilo-Sub TWU series is not equipped with any
integrated monitoring devices.
A motor protection switch must be set up at the
customer!
The AC versions and Plug&Pump systems have an inte-
grated motor protection switch in the start switching
device.

5.7 Motor protection and activation types

5.7.1 Motor protection
The minimum requirement is a thermal relay/motor
protection switch with temperature compensation,
differential triggering and an anti-reactivation device in
accordance with VDE 0660 or the appropriate national
regulations.
If the product is connected to electrical systems in
which faults frequently occur, we recommend install-
ing additional protective devices at the customer
(overvoltage, undervoltage or phase failure relays,
lightning protection etc.). We also recommend install-
ing an earth leakage circuit breaker.
Local and national regulations must be adhered to
when connecting the product.
Installation and operating instructions Wilo-Sub TWU 3..., TWU 3-...-P&P
Terminal
U
V
W
PE
5.7.2 Activation types
Direct activation
At full load, the motor protection should be set to the
rated current at the operating point (see type plate). At
partial load, we recommend that the motor protection
be set 5% above the current measured at the operat-
ing point.
Starting transformer/soft start
• At full load, the motor protection should be set to the
rated current at the operating point. At partial load, we
recommend that the motor protection be set 5%
above the current measured at the operating point.
• The minimum required cooling flow speed must be
guaranteed at all operating points.
• The current consumption must be less than the rated
current during the entire operation period.
• The ramp time for start/stop processes between 0 and
30 Hz must be set to max. 1 second.
• The ramp time between 30 Hz and the rated frequency
must be set to max. 3 seconds.
• The voltage at the start must measure at least 55% of
the rated motor voltage (recommended: 70%).
• To avoid power losses during operation, bypass the
electronic starter (soft start) after normal operation
has been established.
Operation with frequency transformers
• Continuous operation can only be guaranteed between
30 Hz and 50 Hz.
• To ensure the bearings remain lubricated, a pump out-
put of 10% of the rated pump output must be main-
tained!
• The ramp time for start/stop processes between 0 and
30 Hz must be set to max. 2 seconds.
• A period of at least 60 seconds is recommended
between a pump stop and restart to allow the motor
winding to cool down.
• Never exceed the rated current on the motor.
• Maximum voltage peak: 1000 V
• Maximum voltage rise speed: 500 V/rs
• Additional filters are required when the required con-
trol voltage exceeds 400 V.
Products with plugs/switching devices
Insert the plug into the plug socket and press the on/
off switch or let the product switch on/off automati-
cally by means of the attached level control system.
Switching devices can be ordered as accessories for
products with free cable ends. In this case, also observe
the instructions enclosed with the switching device.
Plugs and switching devices are not flood-proof.
Note the IP protection class. Always install
switching devices in such a way that they are
protected from flooding.
6 Startup
The "Start-up" chapter contains all the important
instructions for the operating personnel for starting up
and operating the product safely.
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