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Can anyone tell me, if the carbon brushe wires are reversed on a motor , will this reverse the direction of the motor?
If it does, is this likley to cause any problems due to the rake of the brushes?
Thanks,
Keith.
Re: Motor direction
Shouldn’t do – it’s an AC circuit on the great majority of motors, so the phase switching is controlled by the electronics. Brush rake is nothing like as critical as people think BTW…..
Chris.
Re: Motor direction
Hit “submit”, spotted the spelling mistake and it all went wonky from there…….
I mean, this is just a typewriter with a screen on top, isn’t it?
😀
Chris.
Re: Motor direction
Sorry, Chris I dont agree with you. :eeek: Any motor with “Reaction” brushes (slanted ends) MUST be installed to spin in the right direction. During spin the motor takes much more current than during wash and the way manufacturers have managed to achieve such high power from such a small motor is to use the “armature reaction” to it’s advantage.
When a motor rotates the magnetic field produced by the field windings is distorted. (Twisted in the direction of rotation).
If a washing machine spins in the reverse direction, the extra current is likely ti blow both the motor and the module.
I have worked as a design engineer in an electric motor factory… Believe me. :zap:
Bob
Re: Motor direction
Sorry rushed that one in without answering the original question.
Yes, reversing the polarity of the armature will reverse the direction of the motor. Thats exactly what the timer does to reverse the motor using the subinterval cams. (or a relay on the module on digital machines).
In theory either the armature OR the field polarity can be reversed in order to reverse the direction of spin but on a washing machine it’s usually the armature that is switched rather than the field. This is due to the use of the half field tapping on the field to enable the superspin.
MOST??? washing machines spin in a clockwise direction, however there are a few that spin anticlockwise.
Hope that explains it
Bob
Re: Motor direction
Thanks for all the replies.
My thoughts where in line with Bob’s reply. I wasn’t 100{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} sure so call several colleges who all said no it wouldn’t affect the direction of rotation. Once I had explained my thoughts referring to the way the sub interval cams reverse the motor they then weren’t sure and sat on the fence.
The problems that may be encountered if the motor spins in reverse is interesting.
Keith
Re: Motor direction
bobokines wrote
MOST??? washing machines spin in a clockwise direction, however there are a few that spin anticlockwise.
As a general rule machines with soap dispencer on left spin anticlockwise, dispencer on right spin clockwise.
This is to prevent the centrifugal force of spin pushing the extracted water out of the dispencer.Regards
SparkeyRe: Motor direction
All Hotpoint machines have the dispenser on the left hand side but they all spin clockwise…
If you look at the position where the dispenser hose joins the tub, it comes in at an angle (pointing toward the two oclock position) so a clockwise spin would tend to create negative pressure at that point.
It also creates negative pressure at the pressure chamber orifice (I love that word).
Bob
Re: Motor direction
So is it possible to determine the correct direction of spin from the direction of rake of the brushes?
Re: Motor direction
It is possible but I can’t tell you off the top of my head. The brushes are above and below the centerline of the commutator and (I believe) the skew is in the direction of rotation.
You don’t say what machine you are working on but, as I said earlier most machines spin clockwise.
Many brushes have a “R” or an “L” printed on them, this is the direction of rotation on spin. However, which is which I am not sure.
I’m off on holiday down the west country in about ten minutes and my wife is shouting at me to get moving. 👿 👿
Dave… I’ll wave on the way past. :wave:
Re: Motor direction
There is room for some confusion here so maybe I can add to it by saying that with the motor facing away from you, it’s going anti-clockwise when the drum’s going clockwise if you’re looking from the front of the machine.(That’s if you consider the front of the motor to be the pulley end).
I’d suggest try it very briefly each way round and go for the one that looks right in terms of soap dispenser side. (I can’t remember the last time I saw the drawer on the right.
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