With PM technology for starting, we must know the angle between the rotor and stator to apply the torque in a good way. This is why several times we have an encoder to know all the time where is rotor and stator after a first alignment test procedure. So now of course we have on ATV212, ATV71, and ATV32.. an open loop control law with an angle test on each starting.

In your case, it's a fan so we can say motors are free to align but the position could be different between motors. This is why we cannot use ATV212, ATV32 or ATV71.

The only solution is the new drive design ATVProcess and its new current injection: AST=Rci.

With this setting, starting PM in parallel will be possible, of course only if the motor stops, which is not always the case on an application. This alignment hasn't been developed to catch on fly the speed then if the motor speed is to high drive will be not able to synchronize the rotor to the stator then we have a risk of blocking.

So even with this new setting, we cannot guarantee what will happen with PM control law when the motor has a different load during running. We can do some tests to identify the best solution.

To conclude if the customer is interested in using ATV Process and its new angle synchronization please keep in touch with me and we will make some tests in our lab with a target field test with ATV Process as soon as possible (to be shared with the product manager). So for sure forget ATV212 today.

Note: Motor protection and drive setting will be study at the same time.

Released for:Schneider Electric India