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Old October 17th, 2006, 06:52 AM   #1
SNK
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Unhappy SOT.....Reversing a Single Phase Motor????

Hey Guys,
I have run into a weird problem.
My neighbor has a wood shop in his basement, and has just purchased a furnace-style 120V single phase AC motor. At the same time, he purchased a PowerFist Drum Switch with Forward/Reverse/OFF. On the switch, it is labeled R,S U,V,5,6. They supplied a WONDERFUL schematic as below.

R S

U V 5 6

Most of the Drum switches that I have seen are labelled 1,2,3,4,5,6.




It looks really easy on paper, but has anyone seen any of the above labels before on a STD AC motor? Page 3 on

http://www.mckessockconveyors.com/PD...0Cat%20542.pdf

and

http://static.flickr.com/59/187576722_f686c5884a_o.jpg

For a STD motor, you reverse the Black and Red wires (NEMA)

I need to know where the L1, N and R and B go.......

Anyone out there know what the R,S,U,V and 5,6 mean?
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Old October 17th, 2006, 07:59 AM   #2
jrwb4gbm
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You really need to post a pictoral, diagram, or link to the Powerfist Drum Switch, if you can, for a better answer, but here is my best guess.

In most cases:
R would = L1
S would = L2
U would = T1
V would = T4
5 maybe would = Red or T5
6 maybe would = Black or T8

Use an ohm meter to verify that the switching action is what you
want before powering up the motor. Also the motor must coast to
a stop before switching it on in the opposite direction.
PROCEED WITH CAUTION.
Hope this helps a little.
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Old October 17th, 2006, 08:11 AM   #3
brucechase
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USUALLY, I would say:

R=L1
S=N
U=T1
V=T4
5=5 red
6=8 black

I'm not sure that you have a 6 instead of an 8. In layman terms, R and S or L1 and L2 are the incoming power supply.
U and V or T1 and T4 are the main winding of the motor leads and 5 and 8 are the start windings.


EDIT: I guess I was a little late! I agree, post a link or picture to help us verify what we said. Look at the motor diagram and switch diagram and verify you are switching the start windings.

Last edited by brucechase; October 17th, 2006 at 08:14 AM.
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Old October 17th, 2006, 08:56 AM   #4
SNK
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Thanks for the reply guys. The switch is at my neighbors house.....I will take a pic of it.
The PowerFist website is awful.....www.powerfist.ca.
Of NO USE.
www.powerfist.com takes you to something totally off topic......
I will check it out tonight if I had time....
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Old October 17th, 2006, 12:20 PM   #5
rsdoran
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Everyone has pretty much answered this but I will throw in a couple of pennies worth too.

This page shows the standard motor connections for many motors;
http://www.patchn.com/motor_connections.htm
As you can see a single phase motor just changes 5 and 8 for rotation but the specifics on how the motor is connected depends on the type of motor being used; which I do not see mentioned.

The basic operation of the drum switch is pictured in your link refering to page 3:


As far as I know they are usually numbered:
Code:
1 2
3 4
5 6
but you can use the picture shown and an ohmmeter to test the action and match it to your needs.

I get the feeling you may have a single voltage single phase 120v motor with just 4 leads, 1, 4, 5, and 8. If that is the case this picture that I modified from your link should work.

I will use T# to reference leads on the motor. As you can see there is a jumper between terminals 4 and 6, T5 will connect to 3, T8 to terminal 2, Line 1 to terminal 5, L2 (neutral) and T4 to terminal 1.

This will make these connections:
FWD
Code:
1 - 2 L2 & T4 will connect to T8
3 - 4 T5 to terminal 4 thru jumper to terminal 6 & L1
5 - 6 L1 feeds terminal 6, T1 and T5

L1 feeds T1 & T5 while L2 feeds T4 and T8.

REV
Code:
1 2 L2 & t4 now feed terminal 3 and T5 
| |
3 5 T8 connects to terminal 5 which is jumpered to terminal 6
4 - 6 L1 feeds terminal 6/T1 and T8
L1 feeds T1 & T8 while while L2 feeds T4 & T5.

Hope this helps. NOTE: to get rotation as needed you may have to swap T5 & T8 at the terminals.
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Last edited by rsdoran; October 17th, 2006 at 12:24 PM.
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Old October 17th, 2006, 01:01 PM   #6
SNK
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Thanks Rsdoran.
The problem is, I don't have the switch that is indicated in the diagram. I have the switch that is labelled

R S (incoming)

U V 5 6 Feeds to the Motor

I don't know the schematics of this switch, or the meaning of these alph-numeric codes, that is the problem.
The motor is a STD 120 Single Phase motor. Not capacitor start.

Last edited by SNK; October 17th, 2006 at 01:03 PM. Reason: More information
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Old October 17th, 2006, 01:21 PM   #7
rsdoran
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Ignore the RSUV56 thing, use an ohmmeter and/or open the drum switch to see if the contacts work like the first picture shown above. If I could see how it was labeled maybe I could explain it but overall it is not that important, how the contacts are made via the action of the switch is.

STD 120vac motor is not fully descriptive. There are many motors that may work with 120 or 240 and some single voltage 120vac motors may have 4 or 6 leads.

As you can see the main thing is swapping motor leads 5 & 8 while maintaing power to the other leads.

All the above was provided to offer methods to determine what is necessary to make it work. I thought I had taken a simple problem and provided means to make it more simple but guess not.
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Old October 17th, 2006, 01:31 PM   #8
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I will grab the switch tonight and bring it to work tomorrow, and test it on a stock motor here.
(the STD motor that I was speaking about is a 120VAC, single speed, Black, Red, L1 and N motor.) Purchased from a surplus store, and similar to what you might see in a furnace fan application. Cheap.
Any information you have added is greatly appreciated.
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Old October 17th, 2006, 01:42 PM   #9
rsdoran
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If it is a 4 lead 120vac single speed single voltage motor then the leads will actually be L1=1, N=4, black=5 and red=8. The standard connection for CCW (counterclockwise) is L1-1,8 and L2-4,5. CW (Clockwise) is L1-1,5 and L2-4,8. L1 is the "hot" and L2 is the "neutral".
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Old October 17th, 2006, 08:18 PM   #10
darrenj
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in my previous life!! (about 12 years ago) I also got a powerfist drum switch given to me by a farmer to use on his silo winch..It had the wonderful directions you posted..Good to se somethings dont change!..If i remember it was not set up the same way a normal drum switch was..(such as the one ron posted)..I could be wrong tho, its been so long..but i remeber having a ***** of a time with it..as ron said open it up or ohm it out..

The other thing is can you post the name plate info from the motor..I am trying to remeber the last time i saw a reversable motor in a furnace and cannot..i have seen lots of 2 speed motors tho...

D
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Old October 18th, 2006, 08:01 AM   #11
SNK
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Ok, I have the both motor and switch at work. Everyone is stumped.
I can turn on the motor, turn it off, and turn it back on in the reverse switch postiion, but it is obviously turning the same direction because I have not interchanged the leads.
The motor is an Emerson 120Vac 1/2 HP motor. If you want P/N, I can post it.
I have the R with L1 (1 on the motor), the S with Neutral(4).
I only have 5 and 6 on the switch left, but any combination of these connections trips the breaker as soon as the switch is changed from OFF.
I am truth-testing the stupid switch now.
Man I hate Powerfist., How can someone sell this Shi*())!!!!
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Old October 18th, 2006, 08:32 AM   #12
rsdoran
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When you can please tell us how the drum switch terminals are setup, example:
R U
S V
5 6?

Test the switch and see what its action is, I have seen one difference in my day, usually its 5-6 that always goes straight thru but I have seen 1-2 be used, example:
Code:
FWD 
1-2 
3-4		
5-6		
REV 
1 - 2
3 4
| |
5 6
See the difference.

If it is a reversing drum switch made for use with single phase motors then it can not be that complicated I do not care who makes it.

I think I will politely back away from this. This is a very basic electrical problem that takes about 15 minutes (maybe) to wire up or determine the switch is not capable of doing what needs to be done but the last part I doubt is the situation. No information is being supplied about the switch and I doubt any of the provided info has been used in any fashion.

Good Luck.
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Last edited by rsdoran; October 18th, 2006 at 08:36 AM.
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Old October 18th, 2006, 08:44 AM   #13
SNK
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Rsdoran, I am sorry that you feel offended.
This is not my intention.
I am working with a group of qualified electricians, who have years of experience.
I was mearly hoping to hear that someone has used this terminology before, and I can see that darrenj had the same issue.
Your advice works for the COMMON 1-2 3-4 5-6 switch, but this one is DIFFERENT.
What my point was.....where is the schematic for Powerfist Drum Switches.
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Old October 18th, 2006, 10:42 AM   #14
rsdoran
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I do not know where the schematic is for that specific device and in general it does not matter.

My advice has nothing to do with the numbers 123456, it has to do with finding out how the contacts are made when the switch is used. I will try again.

If this is a true reversing drum switch it will have 6 contact points just like in this picture:




Who cares how they are labeled, does not matter. Take a meter and see if no continuity is present in center/off position. Then move to FWD position and determine what points have continuity. Then move to REV and determine what points have continuity.

If this is any kind of reversing drum switch then one set of contacts should be straight thru in either fwd or rev, like the bottom pair in the pictured example. The other 2 sets of contacts will either combine straight across or side by side as show in the above picture.

The neutral of the motor will directly connect to the motor and to one of the terminals of the switch.

Following me so far? The neutral (T4) is connected all the time so now all you have to do is provide L1 (hot) and swap 5 & 8 between it and the neutral, L1 should always be fed straight to the motor L1 or T1 lead. There will have to be a jumper used at some point as shown in the prior picture.

All I have asked is use a ohmmeter and check the switch action, if it differs from above then show how and use the labels this switch has.

I am not trying to be nasty, just trying to help, but I need you to provide some information to do this.

As an afterthought I once dealt with a reversing switch that did something like this but do not remember exactly:
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Last edited by rsdoran; October 18th, 2006 at 10:52 AM.
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Old October 18th, 2006, 11:41 AM   #15
SNK
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Thankyou for your help Rsdoran.
I will let you know the outcome.
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