# Forward reversing motor starting circuit



## Mak2492 (Mar 22, 2017)

Hello, I currently work for a auto manufacturer. I currently do mainly mechanical work, but looking to do more electrical work. I was wondering if anyone has a drawing of how the words should be ran for a forward reverse motor starter with e-stop. Thanks.


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## John Valdes (May 17, 2007)

Heres a generic drawing.


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## Mak2492 (Mar 22, 2017)

I found this picture, I'm kind of confuesed by the wiring. Would the 3 phase go to the motor contractor? Thanks


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## Mak2492 (Mar 22, 2017)

https://images.search.yahoo.com/ima...v&.crumb=MDV21NbAULq&fr=yfp-hrmob&fr2=piv-web


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## sparkiez (Aug 1, 2015)

To put it simply:

When dealing with ordinary motor circuits you have two separate parts of the circuit: Control and Power.

It is important to not think of all the wires as a single circuit, because they are not.

Power is the 3-phase going to the motor
Control are the devices that "switch" the power circuit.

Being able to distinguish between these two sides of the circuit is the single most important skill you need when working with these circuits next to knowledge of safety.

Now, yes your 3-phase will go to the contactor/contactors

2 Legs of the 3 phase will be swapped to switch the direction. Which contactor is pulled in depends on your control wiring, which is typically lower voltage. 24VDC, 24VAC and 120VAC are the most common.

It is important to make sure that in no way possible at all ever under any circumstances for any reason NEVER both contactors can turn on at the same time or you WILL create a phase to phase short and BLOW SOMETHING UP. It will be a pretty good sized boom. You should really NOT hook up the power wires while you are learning to wire up this circuit until you know the control circuit is functioning correctly.


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## Mak2492 (Mar 22, 2017)

Thanks, I know about putting the interlock from the A1 to A2. In the picture, it looks like they pulled a leg to run the push buttons? Wouldn't those come off the transformer?


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## glen1971 (Oct 10, 2012)

Mak2492 said:


> Hello, I currently work for a auto manufacturer. *I currently do mainly mechanical work, but looking to do more electrical work.* I was wondering if anyone has a drawing of how the words should be ran for a forward reverse motor starter with e-stop. Thanks.





Mak2492 said:


> I found this picture, *I'm kind of confuesed by the wiring. Would the 3 phase go to the motor contractor?* Thanks





Mak2492 said:


> *Thanks, I know about putting the interlock from the A1 to A2. In the picture, it looks like they pulled a leg to run the push buttons? Wouldn't those come off the transformer?*


Are you an electrician? I ask because:
1) Mainly mechanical work.
2) Asking where the 3 phase goes.
3a) A1 and A2 is typically a coil.
3b) From the picture in the link, it looks like it is using a control circuit higher than 120 vac.


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## Mak2492 (Mar 22, 2017)

I'm not really an electrician, just trying to move up in the company. The 3phase would come out of the breaker and down to the contactor wasn't thinking straight earlier. Would then pull 3phase off the other contractor to go to the transformer to get the single phase for the buttons. The part I'm most confused about is just the 110 wiring on the contactors.


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## Mak2492 (Mar 22, 2017)

I was gonna buy 2 starters and and overload and 3 buttons and practice just wiring up the 110 side.


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## telsa (May 22, 2015)

Mak2492 said:


> I was gonna buy 2 starters and and overload and 3 buttons and practice just wiring up the 110 side.


Odds are, you'll 'let the smoke out.'

This is j-man level craft. 

Don't attempt it.


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## Mak2492 (Mar 22, 2017)

So, then how is a person suppose to get use to wiring it up?


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## BrettC (Apr 10, 2016)

Mak2492 said:


> So, then how is a person suppose to get use to wiring it up?


Under the supervision of a trained professional on your way to becoming a trained professional yourself.


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## Mak2492 (Mar 22, 2017)

I was just going to wire up 110. There would t be any 480 involved yet.


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## glen1971 (Oct 10, 2012)

*I'm not really an electrician, just trying to move up in the company*.The 3phase would come out of the breaker and down to the contactor wasn't thinking straight earlier. Would then pull 3phase off the other contractor to go to the transformer to get the single phase for the buttons. The part I'm most confused about is just the 110 wiring on the contactors.

Get some technical training.. It'll teach you how to connect it properly, and also the hazards of what can go wrong... If you blow an interlock because it's wired wrong and both contactors pull-in at the same time, you'll create a phase to phase short and hopefully not get hurt....
Leave this to the trained professionals...


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## sparkiez (Aug 1, 2015)

Are you buying this equipment to set up at your home and practice this?

I know several mechanics who understand motor circuits, and being an industrial maintenance technician, I feel you should understand a basic motor starter circuit.

That being said safety is a pretty big concern, so if at all possible you should try to pursue some kind of training, at least on how to safely handle 480V circuits and control circuits. These circuits often need to have some live troubleshooting done on them, so the potential is there to hurt yourself.


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## oliquir (Jan 13, 2011)

there also solid state contactor motor reverser, no wiring at all to do


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## sparkiez (Aug 1, 2015)

oliquir said:


> there also solid state contactor motor reverser, no wiring at all to do


He is buying them himself, so his best bet is a couple used ones off ebay for cheap.


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## Mak2492 (Mar 22, 2017)

I have a little understanding of the 489 side. It's just running the power from the push buttons to the motor starters then interlocking them together is what I was gonna practice. I fround some for like 15-20 with overload attached already.


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## emtnut (Mar 1, 2015)

Mak2492 said:


> I was just going to wire up 110. There would t be any 480 involved yet.


Just nit-pickin ... but if you have 110 .. then it would be 440 :thumbsup:


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## heavysparky (Jun 2, 2009)

sparkiez said:


> Are you buying this equipment to set up at your home and practice this?
> 
> I know several mechanics who understand motor circuits, and _being an industrial maintenance technician, I feel you should understand a basic motor starter circuit._
> 
> That being said safety is a pretty big concern, so if at all possible you should try to pursue some kind of training, at least on how to safely handle 480V circuits and control circuits. These circuits often need to have some live troubleshooting done on them, so the potential is there to hurt yourself.


or they shouldn't be working the job. just my view. No offense to anyone


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## sparkiez (Aug 1, 2015)

emtnut said:


> Just nit-pickin ... but if you have 110 .. then it would be 440 :thumbsup:


Ever heard of nominal voltage ? :thumbsup:



heavysparky said:


> or they shouldn't be working the job. just my view. No offense to anyone


Yea, I can feel you on the safety side, but the truth is the industry is hurting for all the industrial trades as far as manufacturing goes. Hell, my first job as a PLC programmer I had a 1 month class that taught me very little and a few old timers who didn't know the first thing about connecting to a PLC and programming. I also had a desperate company that saw me messing around on the test bench, so I went from a guy that fixed lights to the company's PLC programmer. Ask questions, used the test bench, studied, read, used the internet, whatever I had to do to learn what I needed. Guess what? The old Control Systems department director told me me once that he didn't know much about PLC's and learned the same way in that plant I did. Good plant? Not so much, but if you get someone like this guy that is determined to learn how something works and wants to put in the effort to learn, even if it is on his time and his dime, don't discourage him, help him and encourage him. He is going to do it anyway, so we may as well make sure to alert him of any potential hazards while at it.

We need more people like him in the field in ALL of the trades.


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## heavysparky (Jun 2, 2009)

sparkiez said:


> Ever heard of nominal voltage ? :thumbsup:
> 
> 
> 
> ...


 

what is your current job and background?


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## micromind (Aug 11, 2007)

Mak2492 said:


> I have a little understanding of the 489 side. It's just running the power from the push buttons to the motor starters then interlocking them together is what I was gonna practice. I fround some for like 15-20 with overload attached already.


This is pretty much how I gained my knowledge too. I've never had formal training, never been an apprentice. Just about everything I know I learned from reading (mostly technical manuals and stuff like that), drawing stuff out (and correcting my drawings, then correcting them again.......lol) hooking stuff up (I usually used 24AC....smaller bang when it went wrong) and asking questions. Pretty much in that order. 

You have one very useful thing I didn't......the internet. There is a HUGE amount of knowledge to be gained there. But you have to sift through a lot of total garbage and bad advice to get to anything useful. 

You absolutely can learn stuff on your own, the keys are to always think ahead and be careful with voltages that can blow stuff up or shock you.


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## emtnut (Mar 1, 2015)

sparkiez said:


> Ever heard of nominal voltage ? :thumbsup:


I think so :blink:

Ever hear of rated equipment voltage ?


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## telsa (May 22, 2015)

Folks, this is journey man level craft.

Period.

The poor OP doesn't even have tutor... nor is he working with a CORRECT and exact functioning 3-phase starter.

The chances of him getting it 'right' are zippo.

I am trying to save him pain, suffering, damage and lost reputation.

Such complicated relays are MUCH more than he imagines.


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## sparkiez (Aug 1, 2015)

heavysparky said:


> what is your current job and background?


I started tinkering with computers when I was about 10. Took all the computer classes I could in high school, including the CCNA program, just never got my Cert. Realized then that sitting in front of a desk wasn't for me.

Fast forward 7 or 8 years, started in the Mechatronics Program at a local community college. Came in and sat through the PLC class even though it was second year.

One year through the program I applied for a job in the controls shop and after speaking with a couple of the old timers I had them pulling for me too. Did mostly fixing lights at first with some pulling wire. The guy training me did all of the pipe bending. He told me to go for machine control, it was a better route and focused my training on machine control. About 6 months in I asked if I could use the test bench and some of the old boxes of PLC stuff to practice on my own time. I was laughed at and told I wouldn't be given access to the laptop because of the damage I could do. I set up the test bench with an SLC and ControlLogix processor and borrowed a key from my school (the instructor didn't know how to get the software working) and installed it on my laptop and bought my own usb-serial adapter.

Kept working on the test bench making all kinds of stuff. Using a process meter to control motor speed, distance sensors, prox sensors, any spare piece of equipment I could get my hands on for about a month after work several days a week. The IT director popped in and saw me one day. Pretty soon he was checking on me regularly and offered me the PLC job at the plant.

I took the job and ruffled a couple people's feathers because of my lack of experience. One of those old timers kept coaching me along and working with me every chance he got even though we were on separate shifts.

I ended up doing a few different systems for plant process stuff, doing lots of debugging and troubleshooting and doing a lot of retrofits. Using forums, reading manuals and making relationships with other vendors and picking their brains on issues, being able to text them to ask questions and such.

Plant politics got to be too much so I quit. The only master electrician that worked there got sick of the same stuff and had told me to call him up if I ever decided to leave, so I now work for him and am learning to use the code book and he is teaching me his side of the trade.

So I guess you could say I started at journeyman level craft and worked backwards. Being from an IT background I had a good idea about how to troubleshoot, the old man showed me how to apply it to electrical systems and how to use hand and power tools properly. The Master electrician is teaching me about how to safely build, and even that other grump old man that wouldn't let me use the laptop showed me a thing or two .

Yes, you CAN teach yourself things. There is nothing magic about what we do. There is nothing unobtainable to those with the drive to learn.

That being said, I realize how unique my opportunity was and that most people will never get the chance to be THE PLC guy in a plant in their second year of training. Damn straight I will capitalize on desperation.


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## MCasey (Dec 7, 2016)

Mak2492 said:


> I'm not really an electrician, just trying to move up in the company. The 3phase would come out of the breaker and down to the contactor wasn't thinking straight earlier. Would then pull 3phase off the other contractor to go to the transformer to get the single phase for the buttons. The part I'm most confused about is just the 110 wiring on the contactors.


Then you should not be doing this task. Call a licensed electrician before someone gets injured or worse.


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## Speedy Petey (Jan 10, 2007)

This is not DIY, but also fits the description. 
This is NOT a place to be feeling your way around guessing at things. You can only ask just so many questions online before you make a mistake and get hurt.
I would also think a company like Toyota would have the proper qualified people doing this sort of work.

Thread closed.


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