Dumb VFD Question

[yhprum]

I bought a vintage Black and Decker electric hammer from the US. It uses 110V AC 60 Hz (or 110V DC) at 3.3 amps.
We use 230 volts AC 50 Hz here in Australia.
I have run it using an AC step down transformer and it seems to work fine like this.
I would like to adjust or reduce the motor speed downward somewhat for some operations.
Would a VFD work like this and eliminate the need for a transformer?
Or would the transformer running through a router speed control be better?
Thanks for your advice.

 

[Bert_]

VFD's, generally, only work on 3 phase motors. Also, aside from a few small drives, they do not change the voltage.

Transformer + speed control sounds like a good bet. The 50/60hz will have no effect on this motor since it sounds like a universal motor.

 

[American Locomotive]

I'm assuming this tool has a motor with brushes? If so, a VFD will have little to no effect on the speed of the tool. A router speed control or variac (variable auto transformer) will be needed to control the speed.

 

[yhprum]

Thanks guys, yes it has brushes and appears to be a universal motor.
I knew it was a dumb question, just not how dumb!

 

[wyliesdiesels]

VFD is for 3 phase motors.

That motor sounds like a single phase motor...

 

[bjcouche]

OK, assuming that the motor is a universal type motor, I see a workable option.

I'm assuming you previously used a 230V 50Hz to 120V 50Hz step down transformer. That would be the preferred and proper way to run that motor at fixed speed. You should not use a 60Hz rated transformer on 50Hz unless it's dual rated for such use or it will overheat.

I don't know if a 120V 50Hz variac exists or a 120V 50Hz router speed controller exists... So, I'm assuming that in your location you can buy a 230V 50Hz variac.

I would buy a 230V 50Hz variac, and then connect the step down transformer between the variac and the motor.
Brian