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.
The W22 Magnet motor 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 does not
require slip compensation either, since the shaft speed does not vary with the load.
F
All W22 Magnet motors present a single configuration of six poles.
Note!
Since this motor is not designed to be connected directly to the power line, all the motors of this line
present a single configuration of six poles and variable electric frequency. For example, the electric
frequency of the 1800 and 3600 rpm motors is:
1800 rpm x 6 poles = 90 Hz
120
F
Note! W22 Magnet motors can be driven by the PM with encoder and Sensorless PM control options only.
The CFW11 inverter is capable to drive both inductions motors and W22 Magnet motors. In order to do
so, you just have to choose the proper control mode, which, in the case of W22 Magnet motors, are: PM
with encoder and Sensorless PM (without speed sensor). The other options: V/f, programmable V/f,
Sensorless and Encoder are intended to drive induction motors only.
Both PM with encoder and Sensorless 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.

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.
g
Never touch the motor terminals while the rotor is spinning, because, even with the inverter shut down,
g
risk of electric 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 motors feature PTC temperature sensors which must be connected to the inverter so that
g
the motor will be shut down in case of overheating.
It is possible to connect the temperature sensor via:
1 - The inverter analog outputs (see Section 15 - Faults and Alarms of the Programming Manual which is
supplied with the inverter in CD).
2 - Accessory IOE-01.
3 - External protection relay with alarm output connected to a digital input of the inverter configured as
general enable or without external fault.
English
3600 rpm x 6 poles = 180 Hz
120
Quick Guide
W22 Magnet Drive System | 3