Motor Starter On-Off Push Button Station Circuit Explained

[Music] hello keith rucker here finish machinery.org guys today i want to put a little video to show how to wire up a motor starter to go on a motor to put a remote switch on it an on off switch now i'm talking about a magnetic type starter that has built-in overload protection this is a standard starter and i've got several examples we're going to show you they're all a little bit different but they all basically do the exact same thing and you just kind of have to figure out what's what on the different models and we're going to show you kind of how to how to figure that out here in just a little bit now i've been working with old machinery for a long time and it seems like every time i get a new machine in the first thing you have to do is deal with electrical issues make sure that it's wired properly for the right voltage and in many cases these old machines that i deal with will have old wiring or stuff will be hanging off of it not hooked up properly wires frayed or the insulation cracking off of it and you have to go in and do work on the electrical systems and at first this is extremely intimidating for me i am not an electrician i'm going to put that out there first and foremost i am not an electrician but i've learned how to deal with a lot of stuff and i've learned how to make things work and learn the principles behind it as far as switching goes the on off switch there's it's really a simple circuit that once you kind of wrap your head around how to make it work a little light bulb goes off in your head and things just become much easier and that's what i want to explain to you today so that if you're having to deal with a switch and get one hooked up whether you're working on an old one or putting in a whole new system you know how to make that circuit work and understand how it works so that you can turn your machines on and off properly so let's start out by taking a look at these motor starters and this is usually it's going to be in a case something like these two this is one that's loose but i just want to show you the differences here i'm gonna pull the tops off of these that one's a square d this one here is a modern style motor starter uh that is uh this one happens to be sold by american rotary um and this is what i think most people are going with on newer equipment now and this is actually the first one of these i've ever dealt with but it works exactly the same as the old style again this is a square d this one happens to be an allen bradley uh but they basically all do the same thing so what does a motor starter do all right to illustrate how this works i'm just going to show you on this one here just to kind of keep it simple you have on the back back here three terminals this is your l1 l2 and l3 it says up here on the top l1 l2 l3 that is your line voltage so your line is coming in here this is the hot power it's non-switched it's on all the time and down here at the bottom you have three more terminals this is t1 t2 t3 the these this is what goes to your load whatever you're powering in this case is going to be a motor it could be something else depending on what you have so i'm going to show you here this is a just a meter that i have and i've got it set on continuity mode right now it's just going to show the circuit when i put these together you'll see this number go up and you'll hear it beep that's just showing that we have completed a circuit we have a closed circuit so normally when i come in here and i go on t1 or excuse me l1 and t1 notice the circuit is open there is a contactor inside of this right here that when it is not on the contacts are open power does not go through them but let's uh i'm going to take and just put this up underneath this terminal here so i'm going to hold it on this one and i'm going to manually engage the coil and when you do notice it closes that circuit now you have power that is flowing through this uh motor starter the contacts are closed let up on the coil it's open i'm going to talk about coil there is inside of this right here and basically an electromagnet when you power it up there's two terminals right here when you put line voltage to this in this case the coil is rated for 208 volts when you put 208 volts across these two terminals it creates an electromagnet boom it snaps shut and at the same time it closes those contacts in there so that the voltage can blow flow through whenever you release the power off of these two there's a spring in there it pushes it apart and separates it and it disconnects that con those contacts and the voltage goes off that is your on off switch so we'll talk about this section down here this is the overload protection we'll talk about that in a minute but right now let's just talk about this part up here because this is uh really the on off part so again normally this thing is closed no voltage goes through you energize the coil boom voltage goes through basically that is how a motor starter works the problem you've got is how do you energize this coil how do you wire it up to do that and we're going to talk about that next actually before we talk about that i want to just show you this this uh one here this is a modern style contactor works exactly the same way though your lines come in the top l1 t1 l2 t2 so we'll put our terminals on those two and there is a coil in here and i'm going to manually press it down notice no beep beep okay so whenever the power goes to this coil and in this case these two screws here a1 and a2 when power goes across those uh it energizes and notice right now the way that this one came from the factory is they had wires that go to l1 l2 so basically whenever the power comes on it's going to automatically turn this thing on we want to make it where we have an on off switch that does that rather than it just automatically turning on before we get to the switch so i do want to talk about the second part of this motor starter and that is this bottom section all three of these have a bottom section on them and this is for overload protection now anytime you're running any electrical circuit you basically need to make sure that you're not putting too much amperage to it where you can burn things up a wire that's going to a machine or to anything in your shop should be sized for how many amps it's going to carry and then you'll have a circuit breaker in your panel that if the load actually goes over that amount of amperage it'll trip the breaker basically what this is is very similar to a circuit breaker but this is going to protect your motor and and the reason that we have a separate place to do this is your your amperage that you want to have is going to vary depending on the motor size that you're running and uh basically what you got are these little heaters in here on these two here these have heaters that go across two terminals that's this little piece here and this little piece here and these are rated four different size motors and you need to look up in a chart and make sure you have the properly sized heater in here what happens is is when the amperage gets above whatever that threshold is it's going to basically open that circuit up and and cause it to trip very similar to a circuit breaker on this one right here is literally mechanical this thing heats up it gets hot whenever it gets to a certain thermal level uh there's a little switch in there and that thing will pop up and whenever it does that there's two terminals back here that it's going to switch on and off reset it you push it back down and that should reset it now let's talk about these little these terminals down here this is a switch and it is a normally closed switch when i say normally closed that means it's going to have power going through it under normal circumstances and if i put my terminals across here boom boom hear the beep okay if um this thing trips it's going to open that circuit and i'll just show you here we'll just strip one of them the beep went off okay so that's going to protect your uh your motor if uh if you get too big of a load on it it starts pulling too many amps we don't want to burn the motor up we want this thing to trip that's exactly what happens notice that we have a red wire here coming off of one of these terminals going to the coil and that's going to be real important all of these have uh that same thing you got the normally closed switch on this one is right here okay and on the modern one that normally closed switch is right here it actually says nc okay normally closed this one says nc this one's not marked but you can tell it's a normally closed switch the other thing that we have um on all all of these uh that's going to be real important for our control circuits is that there is an auxiliary connector in here on all of these that is connected to the coil and it's going to be normally open okay again that means there's not a circuit it's basically going to be exactly like the terminals that are going through here it's normally open whenever the coil pushes in it will close that and create a circuit across that now let's see on this one here here's our auxiliary and we close the coil okay on this one it's these two terminals right here and let's do the coil and on this one it says you gotta normally open this one's actually got a normally open and a normally closed you got both we're only going to use the normally open one the normally closed one is handy if you want to do some more advanced circuits but again we have a normally closed or normally open rather let me show you this and when we push the coil in we got a circuit what i've shown you here is three different motor starters they all do basically the same thing a contactor that lets the voltage go through and we have an overload protection that protects it that trips whenever the voltage or the amperage rather goes above a certain threshold this adjustable depending on this is adjustable by changing the heaters on this one it's actually adjustable electronically you got a screw in here you can just move it back and forth to adjust it that's your overload protection and then we also have a auxiliary contact that is with the coil so when the coil is energized it closes the uh that contact all right so all of these can be wired up exactly the same way a little bit different but it's the exact same circuits so now let's talk about our push buttons that we're going to use here to actually control things this is a push button station that has a start and a stop notice both of these are spring loaded you push it in it's a momentary switch whenever you push it in it creates a circuit or close either opens or closes a circuit depending on which one it is and when you let up it releases and it goes back to its normal position this button here this is another one that does the same thing uh and i got this one because you can actually see it on the bottom there's two sets of terminals and this this switch can either be normally open or normally closed and if you look when you push it there's a little contactor right here at the top two if you if you go across these top two in fact let me just show you we go across those top two that is normally closed hear the beep okay the bottom two is normally open so when we push the button in i want you to see what happens there's a spring in here and there's a contactor across there did you see that you can actually see the contactor go from the top to the bottom so now when we push that this top switch remember it was it was normally closed before now it's open there's no circuit the bottom was normally open which means there was no circuit but now there is a circuit across those two okay so this this this button this push button station can be wired either way this one here uh basically does the same thing uh you've got a start and a stop your start button is going to be normally closed your stop button is going to be normally open so now i want to do is talk about our circuits and how to put in your switches so again we got two switches a start and stop button your stop button needs to be normally closed your start button needs to be normally open and i've got some illustrations here showing this so you got your line voltage coming in to l1 l2 l3 we show in here the contactors they're normally open notice they're all open no power is going through this is your heater block or your your overload protection down here and normally it's going to just go right through that unless it trips this breaker over here so this is a normal position when the machine is off and notice here we have taps we've got to we got to energize that coil the whole thing we're trying to do here is to create a circuit across this right here this is your coil whenever you have that voltage going across that circuit it's going to energize that circuit and it's going to move all of these switches okay from the position that they're in again these are normally open we've got a normally open one here we've got a normally close one on the one the the older ones don't have this one but we're not going to be using it anyway so it doesn't really matter for this illustration i've got it drawn in here but normally you got voltage that's going through your stop button it goes right over here and it's not continuing across because this contact is not closed all right so what happens when we push the start button all right when we push that start button in notice what happens we create a circuit it goes across this momentarily it goes across this and this one comes up it hits the other side of the coil boom whenever that coil is energized it pulls all these things in now our contacts here are are closed the voltage goes through your motor is running okay so we created that circuit but remember this is on a spring so as soon as you let up on that it's going to release that so how does it continue running when that happens so i'm going to show you that well as soon as you let up on that button there that circuit is going to go away but at the same time and really this happened at the same time that you press the button and i'm showing you in two different steps but remember we this switch here your auxiliary switch disconnected to the coil is doing the exact same thing that your contactors are it closed so now we have a line that comes over here it's going across that and that is energizing the coil so once you push that start button it closes that switch and the power is just going through there and then that is uh energizing your coil and keeping it energized all the time even though you release that button this switch over here comes into play that contactor comes into play and that continues to keep your circuit alive so now to stop it we press the stop button in so when we press the stop button in notice what happens here it shorts out or stops this circuit here basically what happens there is that your coil becomes de-energized pop it opens up all these breakers open up so you don't have any voltage going anywhere else and then as soon as you release that button it goes back to the normal state which is uh looking like this right here waiting on you to push the start button to start things back up again now as far as the overload is concerned let's go back over here to where we were on so so as far as the overload is concerned let's talk about it we're back over here where the everything is just running okay everything is going everything is good the circuit is you know we've got the the coil is energized the voltage is going through here got voltage going to your motor now what happens is one of these heaters or the overload it starts drawing too many amps what it's going to do is it's going to trip this breaker down here okay so whenever that happens boom all of a sudden this breaker opens up again it collapses that circuit the circuit in this case it cuts the circuit going off to the bottom down here your coil de-energizes it opens up all these uh these contacts and your circuit is collapsed and basically shuts everything off so this is your wiring diagram you're going to get line voltage coming off of l1 take it over to one terminal on the stop switch your stop switch the other side of that you basically got two different things going on one one wire is going to go to one side of the start button and you got another wire that's going to go over to your contactor block that goes into your coil that's going to open and close there coming off of the start button on the other side of it you got one that goes over here to the coil and we have a short that goes between the coil and this auxiliary line here and that's pretty much it it's a very straightforward three wires is all you need uh to wire up that start stop button all right let's show this all wired up so you can kind of see how it goes uh you got a start stop station over here start is on the top stop is on the bottom okay i'm going to pull this off remember starts from the top stop is on the bottom so what we're going to normally do is remember you have your power coming from l1 it goes over to the stop button this is normally closed so that means that it is normally a circuit across these we have a short jumper that goes across to the stop button our start button the hot side is coming into the bottom of the coil over here and the other side goes into the top of the coil when i say the coil this is a jumper across the coil then we have a jumper from here over to the coil itself and we have a power that comes off of l2 goes through the overload protection and then that goes to the other side of the coil here so when i push the start button again we have a circuit it's coming through here it's going through here it's coming over to this okay so we have power that's coming to here so when i push the start button it creates a circuit across these two here and that sends power to the other side of this connector which in turn is feeding over to our coil our coil energizes snap shut and then whenever i release that button okay now we basically just have power that's coming through um this switch here because it's connected that's gonna turn the motor on when you hit the stop button uh we're basically breaking this circuit here that breaks this circuit uh to the coil the coil collapses everything falls out so there you go that is your quick wiring and that is on this modern style this is the one sold by american rotary modern style starter i'm going to show you on an old style starter showing how the wires are going there as well so now we got your old style starter wired up here as well again this is your coil so we want to try to get a circuit across that coming off of l2 go to our uh overload block this is normally closed nc so that's a circuit going in there and we're powered energizing one side of the coil the trick here is energize the other side of the coil so here's our start stop button here and uh here we go so when i hit the start button up here what's happening we have power it comes in over here this switch is normally closed so it's jumping over to this side of the terminal notice it goes up over here but this one is normally closed it is not allowing power to go through there but when i hit this button we're shorting it out the black wire goes directly to this terminal which is again closed right now but we got a jumper that goes over to the coil that creates our circuit so our power comes through the switch boom right there okay when i release that start button well now whenever the coil energizes it pulls in this contact in here so now we got the circuit coming through here through the blue wire the blue wire comes in here we got a connection inside of this block and that's feeding over here so we got our connection in there when i get ready to stop the connection i hit the stop button and that disconnects between these two so basically that collapses the circuit the power is not coming here anymore the coil de-energizes it pulls everything in it disconnects so very simple circuit very simple circuit indeed and exact same wiring exact same setup no matter whether using the old style motor starter or the new styles well guys hopefully that made sense i know this is it can be confusing but once you wrap your head around this it's really a simple circuit and it really makes a lot of sense and i know some folks just want to just show me how to wire it up it's a lot better guys if you understand what's going on because then you can kind of troubleshoot things and understand if you get something wrong you can kind of see what's going on and kind of be able to figure out what's happening so a little bit of both there you got to see how to wire it up but you also got to see why it's doing what it is one other comment i want to make about these uh motor starters because i always get asked the question why not just put an on off switch on the thing rather than having these momentary push buttons and so forth like that and using these magnetic starters these magnetic starters are here to protect you that coil is your friend and i'm going to give you an example let's just say that you've just got a switch you just go over there and you just throw a switch and it energizes your machine and you don't have a motor starter like this right here well let's just say the power goes out okay when the power goes out your machine shuts off but that manual connection that disconnect connection you connected it and whenever the power comes back on guess what's going to happen your machine is going to come back on that is a safety issue that's a big time safety issue let's say the power goes out and it's out for an hour or two and you're sitting around the shop you got you know light coming in from the windows say well you know what power's out i'm going to go over here and i'm going to clean this machine up real good and you're over there you're leaned over say the chuck on the lathe and then all of a sudden the power comes back on well guess what that machine's coming back on and it could suck in there it could hurt you that's just one example with a magnetic starter one of these starters here when the power goes out it collapses that circuit the coil disconnects so when the power comes back on guess what your machine's not going to come back on until you push that button to start that machine that's just one example of the safety features in there as to why this is actually a good idea to use there's lots of other circuits that you can put in on these things you can put an emergency stop in there you can put lights that come on to show you whether it's owned whether it's off or whether it's tripped whether you've had an overload that's part of the reason why on this more modern style we have those those circuit blocks in there that we weren't using you can use those for doing control indicator lights and so forth like that i don't normally use them but in some situations it's good if you have a control panel and you want to have lights that light up to show you the status of an individual motor or circuit that's on that control panel so they definitely serve a purpose so anyway there you go hopefully guys that does make sense hopefully uh that made things a little bit clearer for you and hopefully now you can go wire up a uh on off switch start stop button station on your machines using uh a common motor starter and with that that's gonna be wrap as always thanks for watching please subscribe to channel if you haven't already thumbs up are appreciated as our comments and guys uh we'll catch y'all next video thanks for watching [Music] you

Channel: Keith Rucker - VintageMachinery.org

Views: 26,052

Rating: 4.9270072 out of 5

Keywords: Machine Shop, Machinist, Lathe, Milling Machine, Restoration, Vintage Machinery, Woodworking, Metalworking, Keith Rucker, VintageMachinery.org, motor starter, american rotary, push button station, motor starter wiring, how to wire a motor starter, motor control, motor wiring, 3 wire start/stop, three wire start stop, start stop circuit, start stop button, motor wiring diagram, motor wiring connection, start stop motor control wiring, self holding contactor

Id: kyX95sW2FmQ

Length: 27min 8sec (1628 seconds)

Published: Fri May 21 2021