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Electrical advice please.

Community Veteran
Posts: 7,928
Thanks: 603
Fixes: 8
Registered: 02-08-2007

Electrical advice please.

I Have an Angle Grinder rated at 650 Watts and runs at a single speed. I also have a small speed control device which is rated at 350 Watts maximum. Is there any safe and cheap way in which I can reduce the power to the Angle grinder ?
The reason I wish to do this is to allow me some control over the speed of a wire brush on the Angle grinder.
3 REPLIES
Community Veteran
Posts: 3,380
Thanks: 2
Registered: 18-01-2013

Re: Electrical advice please.

People can and do use phase control devices to vary the speeds in fans and motors but it's not a good way of doing it. The proper way of doing it is using a different method but this is normally quite expensive and requires three phase motors.
I certainly wouldn't use a 350 watt controller to control the speed of your 650 watt grinder. If you can find a higher wattage controller it's worth giving it a go but I wouldn't run at less than 50-60% of the normal speed or you may run into cooling problems. Bargain on buying a new grinder if it doesn't work and you burn the windings out.
Community Veteran
Posts: 7,928
Thanks: 603
Fixes: 8
Registered: 02-08-2007

Re: Electrical advice please.

I Did find this on e-bay for £20, seems he has sold a number of these with good feedback. To be safe the item would need to be housed in a suitable box.
As it was something I would use as a one off it unlikely I will buy it.
AVAILABLE NOW!! 2000W - 240V - AC MOTOR SPEED CONTROL
Community Veteran
Posts: 3,380
Thanks: 2
Registered: 18-01-2013

Re: Electrical advice please.

For not much more you could probably get a grinder with a speed control built in.