 Time delay relays are often very useful when it comes to sequencing motors when you want them to start a specific time After a push button is started or something else is started and also we can use them to keep something running for a specific time After a stop button has been pushed and that's what we'll be going over in this video is the off delay function of time delay relays Here we have a typical off delay we have a coil much like we have any kind of relay So we have a TDR coil time delay relay coil. It has a timing function of five seconds on it Here I have some normally open contacts some normally closed contacts. Those are instantaneous So what happens is the moment TDR energizes these contacts will close these contacts will open it ignores the time What doesn't ignore the time are these timed contacts down here This is a normally open time to open contact and a normally closed time to close contact The big difference between an off delay and an on delay is that these contacts their timing begins when this relay is De-energized after it has been energized So let's see what followed through the sequence of energizing TDR. I Go ahead. I energize TDR What was once a normally open contact becomes closed and which once was a normally closed contact becomes open So that happens instantaneous now for the off delay contacts These contacts do what they're supposed to you instantly as well So TDR energizes these normally open contacts normally open time to open will close instantly and these normally closed Contacts time to close will open instantly as long as this is energized All of these whether it's these instantaneous contacts or these instant or these time contacts Will stay in the position their energized state. So this will stay closed This will stay open. This will stay closed. This will stay open as long as TDR is energized The magic happens when TDR de-energizes So let's say this TDR was running for about half hour Which means that this stays closed this stays open this stays closed this stays open So that five seconds has nothing to do with any of this when TDR is energized when we de-energize TDR You'll notice that the instantaneous contacts go back to their original state So what was once closed now becomes open and which was once open now becomes closed So they go back to the original state those are instantaneous contacts the magic of the off delay However happens here, you notice that was once closed is still closed and which was once open is still open Because the timing in an off delay begins when the coil is de-energized So what will happen is it will wait five seconds and then this will open it will wait five seconds and this will close Normally open timed to open normally closed timed close So five seconds occurs and then the normally open opens and then normally close closes and it times out So let's take a look at how this would play out in a practical circuit Here I have your basic start stop. So I have my stop my start I have an M contact so M coil my M contact Then I have a time relay coil or TDR coil or just a TR coil in Parallel with the M. I have these contacts which are associated with this coil and another motor So when I press the start button, let's see what happens The moment I press start M coil energizes these contacts close That'll be my hold-in circuit this coil energizes these contacts close and M2 energizes Again, the timing function has no play in this part at all So the moment I hit start this energizes this energizes and this energizes all at the same time Now when I release the start button Everything is held in because of this hold-in contact right here. It bypasses the open there provides a parallel path That stays energized that stays energized that stays closed that stays energized now What happens though is when I hit the stop button, that's where the magic happens with the time delay I Go ahead and I push the stop button which will de-energize this circuit right here The stop button pops back into place. This is de-energized. This is de-energized now This is where the timing begins five seconds after this de-energizes. This will open now Remember this will hold closed for five seconds so M2 will run for five seconds and then this will release this set of contacts and it will open and Then we go ahead and we see that M2 shuts down. So the sequence of events when we start M energizes TR energizes an M2 so motor M starts and motor M2 starts right away When I press the stop button motor M stops instantly motor 2 stops five seconds later And that is how an off-delay circuit or an off-delay relay is used in a motor control circuit