# Allen Bradley 3 position 8 pin Wiring help



## mattjmurph (Oct 13, 2021)

I do not know how to wire this type of switch. I would like to have someone help me.

This switch is being used to reverse polarity on a small motor. 

The motor has a speed control on it as well.

The leads to the motor need to be reversed as well and the leads to the speed control for this fix to work.

The motor has just a red and black lead.

The speed control has also just a red and black lead. 

1 N.O. / 1 N.C., Contact Block


Relatively new at this too. Still learning. 

Need some walk through.



























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## CMP (Oct 30, 2019)

Chew on this sketch and cut sheet. Should be able to get you there. And ditch that ring while doing electrical, for your own good.


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## Breakfasteatre (Sep 8, 2009)

The ring looks rubber.

Are those PB contacts HP rated?


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## Breakfasteatre (Sep 8, 2009)

those are pilot devices not intended to start/stop a motor through interrupting motor voltage


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## Almost Retired (Sep 14, 2021)

Breakfasteatre said:


> The ring looks rubber.
> 
> Are those PB contacts HP rated?


possibly black titanium (or something similar), its what the hip wear nowadays


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## micromind (Aug 11, 2007)

Those black things are rubber flat washers. They act as spacers depending on mounting surface thickness (use fewer of them for thick surfaces) and also sort of like lock washers to keep it from coming loose. 

As noted, the contacts are not HP rated.


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## Breakfasteatre (Sep 8, 2009)

micromind said:


> Those black things are rubber flat washers. They act as spacers depending on mounting surface thickness (use fewer of them for thick surfaces) and also sort of like lock washers to keep it from coming loose.
> 
> As noted, the contacts are not HP rated.


he was talking about the ring on his finger, not the spacers


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## mattjmurph (Oct 13, 2021)

The ring is silicon 


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## mattjmurph (Oct 13, 2021)

This contraption is used to reverse a small 1/2 dc motor, that the switch I don’t believe is supposed to be used for. The correct part is on order, as the original is broken. The lead time is 5 weeks. It is for a 50 year old lathe that grinds rolls, to get marks and what not out of them for a smooth finish for steel costing.

Needless to say, the plant has 20 years of neglect, and it is catching up to them. They are so did if money for updates, but in my opinion on the wrong things, and not the line. However, slowly it is improving.


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## paulengr (Oct 8, 2017)

Logically to reverses direction swap 5 and 8 but leave 1 and 2 the same. So in one direction you have say L1 to 1 and 5, and L2 to 2 and 8. In the other direction it’s L1 to 1 and 8, L2 to 2 and 5.


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## Almost Retired (Sep 14, 2021)

mattjmurph said:


> This contraption is used to reverse a small 1/2 dc motor, that the switch I don’t believe is supposed to be used for. The correct part is on order, as the original is broken. The lead time is 5 weeks. It is for a 50 year old lathe that grinds rolls, to get marks and what not out of them for a smooth finish for steel costing.
> 
> Needless to say, the plant has 20 years of neglect, and it is catching up to them. They are so did if money for updates, but in my opinion on the wrong things, and not the line. However, slowly it is improving.
> 
> ...


AB and others also make what is called a drum switch which is intended for reversing 3 phase motors
this would be something more appropriately rated for a DC motor

DC tends to arc much worse than AC and therefor needs a higher rating
look at the chart in post #4 to see the huge difference between DC and AC ratings


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## oldsparky52 (Feb 25, 2020)

Breakfasteatre said:


> View attachment 169078
> 
> 
> those are pilot devices not intended to start/stop a motor through interrupting motor voltage


I don't think that switch will work long on a DC motor.


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## micromind (Aug 11, 2007)

I don't know the DC voltage but if it's 90 (pretty common DC motor voltage), the switch is good for about 0.7 amp.


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## CMP (Oct 30, 2019)

We never saw a motor, or a speed controller for that matter, just a terminal strip that showed us some terminals that likely don’t apply.
i just showed what he asked for, how to wire a selector switch for reversing. If it’s suitable for use nobody knows at this point.


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## samgregger (Jan 23, 2013)

To reverse a DC motor, all you need is a properly rated DPDT switch - nothing particularly fancy


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## samgregger (Jan 23, 2013)

Or even a single pole switch and a 4-way switch


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## Almost Retired (Sep 14, 2021)

samgregger said:


> Or even a single pole switch and a 4-way switch


what is the DC rating on those ?


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## samgregger (Jan 23, 2013)

Almost Retired said:


> what is the DC rating on those ?


Disclaimer: No freaking idea, depends on how big a DC motor it is to whether or not I would try using plain old snap switches.


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## mattjmurph (Oct 13, 2021)

Almost Retired said:


> what is the DC rating on those ?


I will get the info for the DC motor here in a few and post it. I really appreciate everyone taking them time to help with this. Thank you very much. 


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## mattjmurph (Oct 13, 2021)

Here is the motor nameplate.


















Kind of difficult to see the Info.


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## samgregger (Jan 23, 2013)

You can do it with the switch you have, but you will need some relays as well. I'll try to draw it up here in a few.


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## samgregger (Jan 23, 2013)

This is with 4x SPST relays, which are readily available and cheap. 12v 30A relays can be bought from any automotive store (Napa, Autozone, Advance, etc)

There are way more elegant solutions, but if you want to use the switch you already have, here is how you can do it.


EDIT: Looking back on your switch, I thought it was a simple ON-OFF-ON with one set of contacts. You can simplify this if your switch is rated for the load and has two sets of contacts.


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## oldsparky52 (Feb 25, 2020)

Did you see it wired before it was taken apart? 
Those control switches must be going to some contactor's coil, no?


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## splatz (May 23, 2015)

samgregger said:


> To reverse a DC motor, all you need is a properly rated DPDT switch - nothing particularly fancy





samgregger said:


> Or even a single pole switch and a 4-way switch


A four-way switch is really just a DPDT switch with two jumpers on the switched terminals. I know you can buy regular looking DPDT switches that are HP rated, Hubbell industrial etc., and most of them are center-off so you wouldn't need the single pole switch. I never looked for a 4-way switch that's HP rated.


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## CMP (Oct 30, 2019)

mattjmurph said:


> Here is the motor nameplate.
> 
> 
> 
> ...


I don’t believe that switch is going to work for you, using it to switch the motor current directly. The DC motor tag says 12.5A, the switch contact blocks are rated for 2.5A for DC current as given in the specifications earlier.

What is missing still in your information is the servo motor controller, what you called the speed control. That may have the reversing function built in, and not be required to be reversed directly through the switch contacts. The switch may just need to provide control signals to the servo motor controller. We can’t help much if you don’t provide adequate information to see what your working with.

You need to provide pictures good enough to read the data in them, and see the diagrams if any, or try to look up any manufacturers cut sheets. Provide us data on the servo controller and a better readable photo of the servo motor tag. While your at it, how about the old switch your trying to replace, so we can see what type and rating it is.

Otherwise the help and information you receive here will not be useful to you, and cause you more frustration. Learn how to use that iPhone camera to better document what your working with. If you can’t read it on your screen, neither can we.


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## Almost Retired (Sep 14, 2021)

^ ^ ^ ^ ^ ^ ^ ^ ^ that up there
listen and heed
we need way more info than you are giving
half the story is bad enough
but you have given a quarter at most

unless this is a new installation ?
you should have all the equipment already installed that made it run before
do you know that the switch is the problem from successful trouble shooting?
or is that a guess ?

start at the beginning of the story please
Ex1:
i have a servo motor , 12VDC, 12.5amp
it stopped operating, so i checked the switch and found it broken
i dont have the exact switch, so i am looking for a replacement
(insert pic of old switch and new switch)

Ex2:
i am trying to install a new servo motor , 12VDC, 12.5amp
i dont know how to do it
can any one help me design a circuit for it?
(insert pic of motor tag that is legible or at least list ALL of the info on the tag as it is)
(insert pic of mfg instructions for installation)


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## mattjmurph (Oct 13, 2021)

Thank you very much


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## mattjmurph (Oct 13, 2021)

I’m going to go get a better look at the motor nameplate and type in the information 


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## just the cowboy (Sep 4, 2013)

Post the make and model of the speed control. If it has a speed control chances are the switch only needs to be be hooked up to the control and the control will reverse the voltage to the motor.
Also here is a book on controls to help you learn.

Cowboy


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## mattjmurph (Oct 13, 2021)

Here is the pot that is used for the speed control.












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## Breakfasteatre (Sep 8, 2009)

my dude, you are way in over your head if you are posting a picture of the pot

The switch does not directly turn the motor on and off

the pot does not directly control the speed.

these devices are pilot devices that interface with the actual motor control

presumably there is a motor controller that these would connect to. You need to find that motor controller. It'll probably look like a box with many small terminals on it


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## mattjmurph (Oct 13, 2021)

I know that pot doesn’t turn the motor on and off. That is used on the panel that the user uses to control the speed. I haven’t had a chance to take a pictures of the motor controller. This lathe is over 50 years old and has been band-aid together by so many other people over the years, no one knows what is what. Believe me when I say band-aid that is being nice. The maintenance manager doesn’t care about getting the correct parts or actually repairing or finding the issue that is going on that caused the problem, as he is retiring very soon. He just wants it to work.

Heck, earlier last week he had us put an iceberg relay in to trick out a burner control system to make it think the airflow switch was still working, when it failed. He always says he is ordering parts, but never does or says there are like 6 week lead time to get common items. That the local supply house has on the shelves.

It is very frustrating to say the least. Also there are never any prints around for these much older machines from the 90’s and early 80’s, or 70’s. Mysteriously they have disappeared. 

The new plant manger is to introduce himself friday this week. And rumor has it, the whole plant line, is getting updated. We will see. Years of neglect has caused most of all these problems. 

Please, I don’t appreciate the rude comment, I made it very clear, in my original post my lack of knowing this machine or what is happening to it, I’m trying to learn it. Hence the fact I posted here for advice. 

Show some professionalism, and understand that at one point in your career you didn’t know something too. Everyone starts off somewhere, and gets hit with an overwhelming situation, they have to work through. It is called learning. 

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## CMP (Oct 30, 2019)

Don’t get discouraged and put off by some of the insulting posters here. But you also need to realize that to get proficient assistance, you need to provide the data for us to help.

When you came and asked your question about how to reverse a DC motor with a selector switch, I provided that information for you. But with limited data
you got results that won’t work for your application. It would be much better for all of us, and you, if you could provide as much data and photos with each post, as asked, so that we are able to respond more intelligently to your inquiries without wasting all of our time beating around the bush.

I would recommend to you, when taking photos, that you back away a bit and show a bigger frame of reference, so we can better see the big picture, then if necessary take another close up for any fine details required. For a shiny motor tag, take the shot at an angle to avoid reflectances and keep the flash off. 

Show us the motor drive box overall photos, how it is installed in the machine, and any data it has. Same for the old direction switch, is it the same type as the replacement, does it have any ratings marked on it? We may be able to help you source the proper type, even if the old one is obsolete.

Without any data to go on, it’s almost impossible to provide relevant information. You have to provide some of the up front work, before we can begin to help, were not very good at mind reading here yet.


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## Breakfasteatre (Sep 8, 2009)

I wasn't insulting him, i was just stating a fact. It has been explained several times in this thread what he needs to provide to us 

Up here, our apprenticeship has courses on motor control, and I still have my textbook. The internet also has many resources, including this forum, but you can't really expect to skip the basics. That's what I meant by the over your head comment.

He might get himself in a pickle where without knowing what hes doing, he ends up destroying equipment., let alone putting himself or others in danger. 

as well, I wasn't being paid as a journeyman electrician and working by myself when I was getting my feet in the industrial field. 

Im sure an understanding of motor control was under the job requirements when you applied. 


anyways, find the controller, and we'll point you in the right direction on how to integrate that selector switch, and pot, if thats how it was intended to be controlled


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## mattjmurph (Oct 13, 2021)

I thank everyone for all there help, I’m very grateful for it. After all that, getting parts for this machine built in 1972, wasn’t very easy nor cost effective. Today a new lathe arrived and it is installed. 


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