 Jog circuits are important when it may be necessary to momentarily inch a motor, bump a motor, or have it run for just a brief amount of time as opposed to its normal operation where you may hit the start button and see it run. There are different variations of the jog circuit. In this circuit we are going to be investigating a jog circuit with a selector switch. Now what we have here is a circuit that looks very much like a standard push button three wire circuit. We have our normally closed stop button, our normally open start button, our M coil or our motor starter coil, our three overloads denoting that it's a three phase system. And then we have our contacts, our holding contacts or sealing contacts or auxiliary contacts or two, three contacts however you want to call them that are attached to this M coil. So when this energizes these close. What's different about this circuit is this selector switch. Right now we have the selector switch in the open position meaning that current was that travels through here will not be able to jump across and complete this side of the circuit. So let's see what happens when we push it down on our start button. We should see current flow through, energize this coil, close those contacts and go all the way through. So we have pushed the button down. Our current has flowed through here, energize the M coil and on our way out. It's not happening however and it's important to note that these contacts here my normally open contacts are now closed but the contact, the seal and circuit does not work because nothing can get through to continue to go. So the moment I let go of this button and it springs back up, what'll probably happen or what does happen is the M coil will de-energize. Which it does as you can see here, the M coil is de-energized because the holding circuit is open with this switch in the open position. There's no way for this circuit to be held in when this button is not engaged. Now let's change things up a little bit. What we're going to do is we've closed the selector switch now. When the selector switch is closed when we press this button down, the M coil will energize, the M contacts will close and now we have a complete path and M can stay engaged and be held in. This would be your normal run operation. So with the start button pressed down, M engages. It can flow through this contact because these contacts have closed, flow through the contacts and the moment that this button lifts up, M will stay energized. With the start button up and not engaged anymore in the circuit, it doesn't matter because current can flow down through this parallel path through the holding circuit and keep M energized and hold it in. The only way to disengage the circuit is to push down on the stop button and open the circuit up. We push down on the stop button and what will happen is this M coil will disengage because it has no direct path to energize it and these contacts will open up as well. And we're back to a de-energized state in this circuit. So that is how the selector switch works for a jogged circuit. In the engaged, we have run and when it is open, the start push button just becomes a jog button. And that's how your jog with a selector switch circuit works.