Direction of n AC motor

captainvi...@gmail.com

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Jun 10, 2015, 6:54:01 PM6/10/15

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We had to take apart a motor from a Rigid thickness planer to resurface the commutator. We reassembled the motor and as crazy as this sounds we think that its now running in reverse. If we inadvertently reversed the wires to the brushes would this happen? That seems to be the only variable here. Thanks, Lenny

Rheilly Phoull

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Jun 10, 2015, 7:22:36 PM6/10/15

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wrote in message
news:7e62bbc7-397d-4f53...@googlegroups.com...

You have hit it in one :-)

M Philbrook

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Jun 10, 2015, 8:12:58 PM6/10/15

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In article <7e62bbc7-397d-4f53...@googlegroups.com>,
captainvi...@gmail.com says...

>
> We had to take apart a motor from a Rigid thickness planer to resurface the commutator. We reassembled the motor and as crazy as this sounds we think that its now running in reverse. If we inadvertently reversed the wires to the brushes would this happen? That seems to be the only variable here. Thanks, Lenny

if the motor has 4 wires then yes, you could of reversed the stator
wires.

In cases where there are only two wires and you disconnected the wires
from the stator, you may not have used the correct wire in the stator.

This assumes you are talking about a series type motor.

But pulling a basic series motor appart for a basic clean up
should not cause pain.

I suppose if you damaged one of the wires in the rotor by shorting
together It could go the otherway, however, it should also not spin
as fast as it should have less power now at the shaft and same current
or more.

Jamie

et...@whidbey.com

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Jun 10, 2015, 8:19:19 PM6/10/15

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If I recall correctly a series wound AC motor will not reverse by just
changing the wires to the brushes. You would need to reverse the
connections to the field winding. One end of the field winding is
connected to one AC line and the other end to a brush. Then the
current flows through the rotor windings and out to the other brush
and from there to the other AC line. Did you maybe swap the field
winding connections?
Eric

Arfa Daily

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Jun 10, 2015, 8:53:28 PM6/10/15

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<et...@whidbey.com> wrote in message
news:0bkhna9d522r4k900...@4ax.com...

> On Thu, 11 Jun 2015 07:22:33 +0800, "Rheilly Phoull"
> <rhe...@bigslong.com> wrote:
>
>>wrote in message
>>news:7e62bbc7-397d-4f53...@googlegroups.com...
>>
>>We had to take apart a motor from a Rigid thickness planer to resurface
>>the
>>commutator. We reassembled the motor and as crazy as this sounds we think
>>that its now running in reverse. If we inadvertently reversed the wires to
>>the brushes would this happen? That seems to be the only variable here.
>>Thanks, Lenny
>>
>>You have hit it in one :-)
> If I recall correctly a series wound AC motor will not reverse by just
> changing the wires to the brushes.

I think it will. A washing machine motor is a series connected AC type, and
to reverse it, the controller just reverses the connections to the
brushgear. In order for it to do this, the connections to both the field
winding and the brushes are brought out to the controller.

Arfa

captainvi...@gmail.com

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Jun 10, 2015, 9:38:35 PM6/10/15

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On Wednesday, June 10, 2015 at 6:54:01 PM UTC-4, captainvi...@gmail.com wrote:
> We had to take apart a motor from a Rigid thickness planer to resurface the commutator. We reassembled the motor and as crazy as this sounds we think that its now running in reverse. If we inadvertently reversed the wires to the brushes would this happen? That seems to be the only variable here. Thanks, Lenny

I'm pretty sure that a typical washing machine motor for instance does not have brushes. I think that would make it an induction motor. I have some spare Maytag washing machine motors down in the basement that I liberated from machines at the town dump. They run at 1725RPM, (I think that speed is directly related to line frequency), and I don't think they have brushes either. They do however have centrifugal switches though. So I think that would that make that type of motor a compound type.

My tool motor has two wires coming out of the field that go directly to the AC line. On the other side of the field there are two more wires that go to the brushes. There is no centrifugal switch. And that's it, a very simple scenario. This one I think is a series motor. The other thing is that this Rigid motor spins at 9000 RPM. We're going to try to reverse the brush wires and see what happens. Thanks everyone for the replies. I'll let you know how it turns out. Lenny