Motor Direction Convention.

Thread Starter

MaxHeadRoom

Joined Jul 18, 2013
26,252
I have worked with all kinds of motors practically all my life, and have always used the definition of CW/CCW as when one is looking into the driving shaft.
Recently I had cause to purchase two small fan motors from my local motor vendor and the box specified CCW, I realized afterword I needed CW.
Before returning them I hooked them up and they Were in fact (to me) CW.
Evidently now there are two conventions for motor direction making it rather redundant.
http://www.formtime.com.hk/cgi-bin/main.cgi?content=faq.htm#rotation
The motors I purchased did not state the viewed direction.:(
Max.
 

wayneh

Joined Sep 9, 2010
17,189
I had a science teacher in grade school tell the class one day that the planets went around the sun in a clockwise direction. I burst out laughing. When she asked why, I asked back, "Are you viewing from above our northern hemisphere or from the south?" She insisted it didn't matter. I burst out laughing again, and was promptly sent to the principal's office for reprogramming.
 

crutschow

Joined Mar 14, 2008
31,100
My understanding also, was that the convention was facing the output shift.
For comparison, according to this, engine rotation is from the main output (flywheel) end.
 

crutschow

Joined Mar 14, 2008
31,100
I had a science teacher in grade school tell the class one day that the planets went around the sun in a clockwise direction. I burst out laughing. When she asked why, I asked back, "Are you viewing from above our northern hemisphere or from the south?" She insisted it didn't matter. I burst out laughing again, and was promptly sent to the principal's office for reprogramming.
So, no alternate facts allowed, eh. ;)
 

nsaspook

Joined Aug 27, 2009
10,663
I have worked with all kinds of motors practically all my life, and have always used the definition of CW/CCW as when one is looking into the driving shaft.
Recently I had cause to purchase two small fan motors from my local motor vendor and the box specified CCW, I realized afterword I needed CW.
Before returning them I hooked them up and they Were in fact (to me) CW.
Evidently now there are two conventions for motor direction making it rather redundant.
http://www.formtime.com.hk/cgi-bin/main.cgi?content=faq.htm#rotation
The motors I purchased did not state the viewed direction.:(
Max.
Strange, I've never seen it other than the way you have always used.

Must be motors produced for and sold to Australians.
 

Tonyr1084

Joined Sep 24, 2015
7,190
I had a science teacher in grade school tell the class one day that the planets went around the sun in a clockwise direction. I burst out laughing. When she asked why, I asked back, "Are you viewing from above our northern hemisphere or from the south?" She insisted it didn't matter. I burst out laughing again, and was promptly sent to the principal's office for reprogramming.
That's too funny.

If you view the earth from the northern pole (or from the star Polaris) the earth is spinning CCW. The sun rises in the east and sets in the west. Now, the sun may appear to move in a clockwise direction, but in fact, the earth is spinning counter clock wise. Also, it's my general understanding that the orbital direction viewed also from the northern hemisphere is also CCW.

I have to laugh with you at your science teachers statement. Your point is 100% valid. Perspective is important.

Max: My understanding like yours is that you view the output shaft from outside the motor. CCW means it's turning to the left (top over bottom). I must confess, whomever made your questionable motors may have not known this convention and may have arbitrarily stated it was CW regardless of convention. I've NEVER heard of viewing a motor's output from behind the motor.

The engine in my truck spins CCW when viewed from the front bumper. But if you could view it from the passenger compartment it'd be spinning CW. Relatives. Can't live with them. Can't shoot them.
 

GopherT

Joined Nov 23, 2012
8,012
My son was studying the continents in 6th grade. The last continent was Antarctica. He was given a homework page that had a map and a list of questions asking which coast had a certain oceanic feature or geological feature. There was a compass rose in the bottom left with standard N, S, E, W labels - Eventhough it was Antarctica. He figured it was a trick and he said all features were on the northern coast.

His teacher failed him and sent him to the principals office when he complained. The principal laughed when my son explained why he was there. The next day, I got a hand written apology from the teacher for sending my son to the office. I sent it back telling the principle it was addressed to the wrong person. He later told me the teacher refused to send my son an apology letter. All was soon forgotten except for a good story once in a while.
 

Tonyr1084

Joined Sep 24, 2015
7,190
Teachers! What do they know?!

And yes, they will almost never apologize.

In grade school, they had just finished rolling the field with an aerator machine. This left plugs of dirt clods that we began throwing at each other. I got caught and was made to stand on the yellow line in the playground. Another student was still throwing them at me and I was merely ducking them. The teacher accused me of continuing to throw them when I wasn't. The principal took me to his office where I explained. The teacher came in and accused me of calling her a liar. On top of that my parents believed her over me.

OK, kids lie. But I was never known to be a liar. Talk about unfair!

Motors. Back to motors. I was recently asked "You just installed a motor, pushed the start button and now the conveyor is going backwards. What do you do?" So I asked "Is it three phase?" To which the response was "Yes." So I said "Swap two wires." Had it been a single phase motor and was going the wrong way then I'd have said it was the wrong clocking. (CW versus CCW).
 

MrAl

Joined Jun 17, 2014
9,622
Hi,

When looking at a motor from in front of the motor if you are in the northern hemisphere it rotates clockwise, but if you are in the southern hemisphere it turns counter clockwise. :)

If we had a motor turning a 'seconds' clock hand in the normal clockwise direction, when looking at the clock face the motor would have to be behind the clock so that would establish the clockwise rotation.

To throw a wrench in the works, i think a drill motor is actually figured by looking at the workpiece from behind the drill. It's as if the drill was turning a regular right handed screw so it turns clockwise to screw in, counter clockwise to screw out. Same with a drill bit of the regular type, it turns clockwise to drill, counter clockwise to back out of the hole if needed.
You could check this though by reading on the web.
 

Tonyr1084

Joined Sep 24, 2015
7,190
Not sure I understand the 'Clocking' term?
Maybe I mis-used the term.

I have reversed the rotation of motors by swapping the stator coil or the armature. In the case of small induction fans, if it's a left hand spin (CCW) and I needed right hand I'd just take the armature out and swap it around. Can't do that with something like a 1/2 HP motor (or larger). Turning the armature around would put the output shaft on the opposite end of the motor. Yes, it's still going to spin magnetically in the same direction, but with the output shaft on the other end - it's going to be going in the opposite direction. But then you have the wire connections on the working end of the motor (where a pulley or gear would reside).
 

Thread Starter

MaxHeadRoom

Joined Jul 18, 2013
26,252
Maybe I mis-used the term.

I have reversed the rotation of motors by swapping the stator coil or the armature. .
You are basically referring to small shaded pole motors, and yes, that is the only way to reverse direction, with larger 1ph induction motors, they obtain the second or split-phase from a capacitor and a start/run winding in place of a shading ring.
These can be reversed by simple connection change.
Max.
 

BillB3857

Joined Feb 28, 2009
2,567
They also make motors with a shaft coming out both ends. One end has a cover that can be moved to the other end if the direction of rotation is wrong.
 
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