Safety Measures - WEG W22 Magnet Drive System Guía Rápida

1 - Technology
W22 Magnet Drive System is a drive system composed of the W22 Magnet permanent magnet synchronous motor
and the CFW11 frequency inverter. W50 Magnet is a permanent magnet synchronous motor.
The W22 Magnet and W50 Magnet motors features three-phase stator winding, similar to an induction motor, and rotor
assembled with permanent magnets instead of a squirrel cage. The permanent magnets eliminate the need of current
induction on the rotor (magnetizing current); therefore, with no load the motor presents a very low current, just enough
to make up for the losses. Besides the magnetizing current, the W22 Magnet and W50 Magnet do not require slip
compensation either, since the shaft speed does not vary with the load.
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Note! All W22 Magnet motors present a single configuration of six poles.
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All W50 Magnet motors present two pole options: six poles and eigth poles. Six pole W50 Magnet
Note!
motors have rated speed of 3000 RPM or 3600 RPM and eith pole W50 Magnet motors have rated
speed of 1800 RPM or less. Special projects may vary.
Since this motor is not designed to be connected directly to the power line, all W22 Magnet motors and W50 Magnet
motors present six or eigth poles configuration and variable electric frequency. For example, the electric frequency of the
1800 and 3600 rpm six pole motors is:
1800 rpm x 6 poles = 90 Hz
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W22 Magnet and W50 Magnet motors motors can be driven by the PM with encoder control,
Note!
Sensorless PM control and VVW PM control only.
The CFW11 inverter is capable to drive both inductions motors, W22 Magnet and W50 Magnet motors. In order to do
so, you just have to choose the proper control mode, which, in the case of W22 Magnet and W50 Magnet motors,
are: PM with encoder, sensorless PM (without speed sensor) and Voltage Vector WEG for Permanent Magnet
Machines - VVW PM (without speed sensor). The other options are intended to drive induction motors only.
Both PM with encoder, Sensorless PM and VVW PM control modes allow driving with constant torque all along
the speed range. Between 0 and 240 rpm, the Sensorless PM drive presents a more intense magnetic noise, which
is characteristic of the control method. In this speed range, the IGBTs are driven with switching frequency of 5 kHz
(regardless the value set in P0297 - switching frequency). On the CFW11 inverters of mechanics E or above, derating
must be applied on the output current so as to allow their operation with switching frequency of 5 kHz - see Chapter 8 of
the CFW11 User's Manual.
VVW for PM motor (Voltage Vector WEG for Permanent Magnet): It uses a control method based on the voltage-
oriented vector control technique for permanent magnet motors with good performance for systems with slow dynamics.
This control is user-friendly and provides high performance, reducing losses and saving energy, due to the tracking of the
maximum torque per ampere and the maintainability of current stability. In this control strategy no self-tuning is required;
however, to achieve a good regulation, the motor nameplate data must be entered into the oriented START-UP. This type
of control is ideal for medium and high speed applications which do not require a fast dynamic response and focused on
energy efficiency such as the driving of compressors, pumps and fans.
On the other hand, the VVW PM is not recommended for applications requiring fast dynamic response or precise torque
control that are focused on dynamic performance such as dynamometers, cargo handling (elevators, cranes, hoists) and
applications requiring performance similar to servomotors such as CNC machines and machine tools.
VVW PM control is available for CFW11 inverters supplied with magnet motors from june, 2021. It is
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Note! possible to include VVW PM control on other CFW11 inverters with a firmware update. Please contact
WEG for more information.

2 - Safety measures

Any service on the internal parts of the motor must be performed by qualified personnel only, since,
due to the attraction between metallic parts caused by the magnets, risk of accident is present
both in the assembly and disassembly of the motor.
People that use pacemakers cannot handle these motors. The permanent magnets can also cause
disturbances or damages to other electric equipment and components during service.
Before opening the terminal box of the motor, make sure the motor shaft is not spinning.
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Never touch the motor terminals while the rotor is spinning, because, even with the inverter shut down, risk of electric
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shock is present. If it is observed the possibility of the load to accelerate the motor shaft, it is necessary to install a
disconnecting device between the inverter and motor terminals.
W22 Magnet and W50 Magnet motors feature temperature sensors which must be connected to the inverter so that
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the motor will be shut down in case of overheating.
3600 rpm x 6 poles = 180 Hz
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W22 Magnet Drive System and W50 Magnet | 3
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