480V Transfer Switch Wiring Completely Melted

[00:00:03]Two, one.

[00:00:07]Good.

[00:00:08]Hey guys, Ben with Up Country Electric.

[00:00:11]Got a uh repair call today. Couple weeks ago, our guys found on a trouble call a automatic transfer switch that had uh burned up on one of its central phases, centered lugs, uh one of the phase input terminals. It looked like to them that it was kind of an internal area of the switch and not so much the uh lugged connection or where the wire landed, but there was such thermal runaway that the whole area was pretty well melted. I'll throw up some pictures here. You guys can see for yourselves just how bad uh it got. Anyway, the uh we had the switch guts removed and sent back to the manufacturer to get rebuilt. Uh, and in the meantime, this uh the customer has had all their switching automatic switching bypass, so they haven't had any backup power available. Uh, so today, we're going to go and put the refurbished new uh transfer switch guts back into the transfer switch can, get everything terminated, and test out uh generator operation and backup power operation, and make sure everything's working as it should. All right, we'll see you there.

[00:01:29]All right, here's our transfer switch.

[00:01:33]It's currently just a junction box.

[00:01:37]We have our what is this? Normal feed from the utility and our load. And then this particular one has cam connections for a portable generator. Here's our portable gen cables.

[00:01:52]Uh you can see there's still a bunch of ash and stuff in here. And you can even see where the worst of it was happening.

[00:02:01]And heat damage on the top. I'm gonna put on a pair of gloves and give this thing a wipe. Just a cursory clean and a little vacuum on the bottom. Then I need to shut down power, shut the sight down, and um get the new gear in and get it all landed.

[00:02:20]Um yeah, pretty simple. I've also got a photo from the tech of exactly where all our control wiring was previously. So, I'll be putting all that back exactly as it was. And I'll just explain to you guys basic transfer switch operation.

[00:02:36]This is a good opportunity to see exactly how they work. All right.

[00:02:41]So, uh I just tried wiping it out and it came a little bit off some of the surfaces, but it's quite a bit of soot.

[00:02:48]So, I'm using this uh Simple Green foaming coil condenser. Foaming coil and condenser cleaner. I'm not sponsored, but this is about the best degreaser I keep on my truck. Let's see if this works.

[00:03:03]There's also one area right where the worst of the damage was, uh, where the paint itself looks a little damaged. So, I think I'm going to hit that with some Rustoleum.

[00:03:15]My go I'll never really get the full smell out of here, but my goal is to try and uh Oh yeah, that's working. Try and at least make it better, you know, clean it up so that uh the can is nice.

[00:03:30]Oh yeah, that's actually working pretty good. Look at that.

[00:03:37]Oh yeah, nice. That actually cuts right through it really well. Nice.

[00:03:42]Yeah, the top is really city.

[00:03:47]It must have been smoking, smoking and blazing.

[00:03:53]Probably a bright orange indicator light there at the end with how much heat was on that lug.

[00:04:03]But, uh, yeah, we'll get it nice and cleaned out.

[00:04:07]And a little bit of paint is right here. I can't tell if the paint's damaged or if it what that is, [music and singing] but but yeah, we'll just put a little bit of effort towards it.

[00:04:23]Better than no effort at all, you know?

[00:04:25]It's like I don't need to make it completely perfect again, but I'm just going to try and make it better than how I found it.

[00:04:38]So, yeah, just keep wiping at that for a little bit. Wipe up all my cleaner.

[00:04:45]Yeah. See if we can make it look a little better. All right, that's better.

[00:04:51]Just put some Rustoleum up top there where I couldn't get the worst of the damage where the paint seemed like it got took the most brunt of it.

[00:04:59]And yeah, a little bit of time spent wiping. It's not perfect, but it's uh much better than it was. We'll go ahead and uh shut down power for safety before I start moving anything big and metal in here. And uh yeah, we'll get the guts in.

[00:05:18]And here's our main.

[00:05:22]Okay.

[00:05:27]And I guess I can check for voltage.

[00:05:31]in these little caps. Perfect. Let's do a voltage check.

[00:05:37]Okay.

[00:05:38]Pop these little caps off.

[00:05:43]We've got a ground bus there. That works.

[00:05:47]Voltage zero zero [music] zero. and phase to phase zero zero and zero. Okay. Yeah, we are cold. The only voltage that is present in here possibly are these cables coming from the generator uh from the generator's battery. And we're going to find out if it did lose all its charge.

[00:06:14]It looks like though it's plugged into a separate outlet over there. So, uh it should have been charging and maintaining its battery charge this whole time. So, we do have 12vt DC here.

[00:06:23]We'll just be careful with those when we terminate them. So, here's our rebuilt transfer switch. You can see up top here. Looks very nice and new compared to uh how it was previously. Looks like they also rebuilt the bottom perhaps. Or it does look like the same one from the photos. And that's a telltale that it's the one from the photos cuz that wire is also cut off inside and these screws being up. So, it is the same one. You can see here we've got phase 1, 2, and three. Then these little feet, this linkage arm, and then phase one, two, and three for generator. So, this is normal supply, generator supply, and load. And you can see back there, there's phase one, phase two in the middle, and phase three right here along the side. And here's your load one, two, and three. So, right now, both switches are open. There's two switches here. See these contacts are floating.

[00:07:26]But in normal operation, this bar would be up here and those would be closed and generator would be open. Uh and then during a loss of power, the brains in the switch on the door of the switch are run by the generator's battery. So the brains stay up during a loss of AC power. The brains see that AC power is lost. They tell the generator to start. When they see good voltage down here on these probe wires, they see good voltage on these lugs. The brains then open the switch. See if I can do it with one hand using this magnetic coil here on this bar. And then now the switch is totally open. And then they close to the other direction. Boom.

[00:08:12]So takes it off of utility, opens it to everything, closes it to generator. Then the load is now running on gen. When the utility is restored, the the brains in the on the door will see good AC power here for a certain amount of time. Then will cycle over. See if I can you can use these handles, but essentially this magnetic coil opens and then closes.

[00:08:39]Now it's closed to utility and then the generator will have a short cool down cycle and then the brains in the switch door will tell the generator to turn off. Um that's basic transfer switch operation. This one's just a 100 amp 480. So everything's tiny relatively and it's also very uh exposed which is nice.

[00:09:00]It makes it a good opportunity to see all the different parts. These are all just dip switches that change state based on weather.

[00:09:10]There's a small wooden bar in there that passes from there all the way along and to these dip switches. I don't know if you can see them. Yep, there's the dip switches right there. So, as it changes state, see if we can operate that.

[00:09:30]There you go. the dip switches fire and then as it opens the dip switch is open. And there's another setup here as well. And those are for auxiliary contacts for a customer. They're also for the brains to know what position the switch is in. All right, let's get it mounted and let's get it wired and then we can start powering it up and testing everything.

[00:09:59]Okay.

[00:10:03]Nice and easy. Very good.

[00:10:29]All right, looks like everybody's going to reach.

[00:10:48]Yeah.

[00:10:50]Good.

[00:10:53]I don't see any damage on this middle phase from the source.

[00:11:02]They must have cleaned it up really good or taken cutting it off. Or maybe they pulled in all new wire. I bet they did.

[00:11:09]Yeah, cuz in those photos, this wire was like way out cooked. So, they must have pulled in new wire. That's awesome. Good job, team.

[00:11:20]And then our load wires are going to make their way over here.

[00:11:25]Good. They'll all reach. I'm going to get these lugs prepped. They've got these little bits of tape on there that are kind of tricky to get off. A little tweaker screwdriver for that.

[00:11:38]Perfect.

[00:11:41]And then I like to just land stuff like this. just get it snug and then bust out the torque wrench and the paint. That way I just focus on bending and getting it in there. Uh, and then I'll methodically go over each lugged connection with the torque wrench all at once.

[00:12:04]That way I don't have to pick up and put down the torque wrench. I don't know, just personal preference. the end of the day, as long as the connections are good, marked, torqued, and safe, that's all good. We really, myself included, peered over those photos and uh our whole team really looked at them closely and looked at the switch closely. I was uh off island at the time on vacation and yeah, it really didn't look like the lug was the issue. It looked like in the very back uh the heat came from lower.

[00:12:41]With most thermal runaway events, my experience is you can tell where the problem was because that's where the most damage is from the heat and it was to me in those photos it was centered back here very low. So, uh on top of that, we had a torque for port and torque marks on everything. So, there's really not much you can do. I guess it's that kind of stuff just happens. So I guess it's just eeny meeny miny mo. Who do I want to land first?

[00:13:10]Let's just do the supply first.

[00:13:14]316.

[00:13:16]It is perfect.

[00:13:19]So bring these bad boys up.

[00:13:22]Look at that. Perfect fit.

[00:13:33]Like I said, I just like to snug them in there by hand and then come later with the torque wrench all at once. This guy is going to end up being what is that?

[00:13:54]120 inchbs or 13.6 6 Newton meters for continental types.

[00:14:06]120 inchbs. What is that? 10 10 foot-lb.

[00:14:12]Not very much, but uh if that's what the manufacturer wants, that's what the manufacturer gets.

[00:14:25]There we go. Just tacked. Just attacked.

[00:14:28]And then we can do our load.

[00:14:32]out the side.

[00:14:39]Very good.

[00:14:43]And then our emergency power.

[00:15:05]These fine strands really fill up these lugs.

[00:15:11]That'll do.

[00:15:32]Okay, those are all ready to get torqued.

[00:15:38]And now's a good time. I'll grab my torque wrench and we'll get them up to 120 inchbs. All right. Okay.

[00:15:47]Torque wrench. Here we are just going up.

[00:15:55]There's seven 10 10 footbs aka 120 inchbs.

[00:16:16]Click there in.

[00:16:28]When I first started out, I never used a torque wrench.

[00:16:32]Um, I think we had one.

[00:16:36]The guy who trained me, my boss, I think we had one somewhere in the shop. It was like a needle type, not a click type. And I only remember using it once or twice and uh we would just tighten the heck out of things. Um and then I remember the first time I used one I thought, "Holy moly, that's all they want. Seriously, that much force." And uh it just really surprised me because I had been really sending it much further than that. And um yeah, I've just come to appreciate the safety of following the manufacturer's specifications because if I go full ham um and break the lug off or snap the equipment and I wasn't using a torque wrench, the manufacturer is like, "What'd you do, bro? You broke it."

[00:17:38]That's what you did. You You broke it.

[00:17:41]Um, but if I'm tightening it with a torque wrench and something snaps off before I get to torque, then it's not me.

[00:17:52]I was just following the instructions and it's on the manufacturer. Uh, likewise too, if something burns up and I've got it to torque, then hey man, I followed the instructions. I torqued it.

[00:18:06]Um, it is a whole business of doing thermal scans of equipment. shutting them down and doing torque checks where you loosen them off and retorque them from thermal fatigue. So, you can have something torqued at an original install and still need to regularly come and check its torque and do thermal scans as part of your preventative maintenance.

[00:18:24]That's something we really try and sell to customers. A lot of people don't want to pay for it until uh something like this happens. So, I think these guys might be um what would you call it? ripe for getting on a regular thermal scan at least annually of all their equipment under load. So, uh, okay, that's all torqued. I'm not going to torque the control terminals. I I know what's connected and what isn't with them. I think we're ready. I need to fix this ground reference wire. And then I need to land all the controls. And then we're getting really close to doing ourh testing. All right. Actually, I almost forgot. The most fun part of torquing is painting all the lugs. So, I'll go get my paint marker and we'll put some colors on there. [snorts] I like this cross check torque seal.

[00:19:15]Comes out almost like a paste, but uh it's very bright, easy to see, easy to apply. And I just put a little dab on the threads and the lug.

[00:19:30]Try not to make it too messy, but hey, what are you gonna do?

[00:19:35]It's uh it's on there to show something, not necessarily to look very pretty, but a little dab will do. This is not one of those cases where bigger the gob, better the job.

[00:19:52]Here we have a peek at that.

[00:19:56]All right, now we're ready for control wiring.

[00:19:59]Okay.

[00:20:01]Fortunately, uh when our team took it apart, they got a really nice picture of the control terminals there. So, I can just follow that and we should be good.

[00:20:14]Uh the way this particular site works, there's a well pump here and uh whenever there's actually a handful of pumps. If the power is out and there's no call for water, nothing happens and that's coming through these control wires here. However, if there is a call for water while the power is out, the transfer switch will then call for the generator. I believe the way we I believe the way that that's achieved is uh there's a dry contact within this switch itself call forgen and we took that here and put the SCADA in series with that so that it has the switch has to be asking for the generator and the SCADA has to be asking for the generator in order for it to uh in order for it to start. It looks like we've got white blue on one.

[00:21:35]Sometimes a picture is worth a thousand wiring diagrams. So, it was very good that a picture of these control terminals was taken.

[00:21:46]Otherwise, I would be reverse engineering all this, which wouldn't be the end of the world, but just be quite a bit of added time. Okay, so that terminal strip, white, blue on one, gray on three, blue, white on six, and gray on eight. Jumped from three to eight.

[00:22:06]Perfect. Then down lower.

[00:22:10]Looks like we've got our DJ number 10 on one.

[00:22:29][snorts] There we go. on eight. I think that's everyone accounted for.

[00:22:45]Uh, got that earth reference on the neutral. Just need to pop these guys onto one of those.

[00:22:52]Yeah. And then I think we're ready.

[00:22:53]Clean up all these wire nuts. Okay. Let me get that equipment ground, get this cleaned up, and uh we'll power up.

[00:23:00]All right. Got our generator cables all connected.

[00:23:04]we can hook up our [clears throat] uh control bundle wires.

[00:23:09]So, these go in the bottom like so.

[00:23:15]And this guy goes in the top. We should have power on our brain board now.

[00:23:23]Very good. So, source one failure.

[00:23:27]That makes sense because there is no source one. Source two failed. It also makes sense because there is no source two connected. You when you have a utility that would be on or a gen that would be on and I don't believe it doesn't look like it's trying to start the gen.

[00:23:47]But uh switch one and switch two open.

[00:23:50]So see you can also tell that the switch is in a center position. So we've got no AC power applied.

[00:23:58]For starters, we're just going to put it on utility by pushing up. So now those are closed.

[00:24:06]Let's go ahead and turn on our utility and just make sure that it's happy in utility mode with everything sitting here like normal.

[00:24:19]Okay. So now source one is acceptable.

[00:24:24]The switch is connected to source one.

[00:24:27]60 hertz, 485 volts, 280 line to neutral. We're not really using that one, but it's still good to see. So, this is everything happy and normal.

[00:24:37]Nothing out of the ordinary. Nothing weird going on. No start request. Switch one closed. So, we're going to go ahead.

[00:24:44]Let's go put the generator in automatic and let's close the generator breaker and let's try and see uh if the generator starts. I'm think the generator battery should be good. If it was dead, this would not have any power and would be cold. So, uh, yeah, let's go get the generator and automatic and then we'll look at the next step.

[00:25:06]Okay, generator controls.

[00:25:10]Main breaker. Good.

[00:25:13]Automatic.

[00:25:19]Okay, now that we've got the generator armed and ready, we're on utility power.

[00:25:22]The first test I want to do is shutting off utility power and seeing that the generator does not start. Um, as long as there's no call for water, I have all the water system in off, the generator shouldn't start.

[00:25:37]Then once I see that, I'm going to go ahead and enable a call for water and we should see a generator crank and turn over and run. So, let's give that a try.

[00:25:48]Okay, shut off the main Nothing should happen.

[00:25:57]Nothing's happening. That's good.

[00:26:01]Start delay. Start request.

[00:26:04]But I believe that start request is in series with the control system.

[00:26:11]Failed to start.

[00:26:14]Switch two failed.

[00:26:18]Switch one fail. or source one failure.

[00:26:21]Swiss source two failure was that first one.

[00:26:25]Source two loading frequency loading voltage. So basically it's not seeing source two when it wants it.

[00:26:34]Failed to start. So I believe it's just going to cycle through all those. Here we are back at the status screen. We're still in source one. Closed to source one. You can see that here. And everything's just waiting.

[00:26:48]So, now that everything's off, we're going to simulate the upper tank in this case, which is what decides when water is needed. We're going to simulate that calling for water. I'm going to put one of the pump systems into hand, and we should hear the generator start up. This should see the generator voltage, and it should close. So, we'll give that a try.

[00:27:15]Here we go.

[00:27:18]>> Call for water.

[00:27:21]Generator warming up. It likes source 2.

[00:27:25]And so it's got a 5m minute warmup for the generator before it puts it under load.

[00:27:32]Very cool. So we'll come back at the end of that 5m minute countdown and it should switch over to gen.

[00:27:40]Okay, here we are. 10 seconds left. What we should see got 10 seconds. What we should see is it open position and then transfer to gen.

[00:27:59]Okay. Then it has a 30 second delay as well between transferring to source two.

[00:28:11]Uh 10 more seconds and then it's going to kick down to the generator and we should hear it load up because it is calling for the pump.

[00:28:21]Two one.

[00:28:25]Good.

[00:28:28]And the pump should be starting.

[00:28:33]Oh, yep. I can hear the generator coming under load.

[00:28:41]Not a very big load for a generator this size, but uh very good.

[00:28:47]Awesome.

[00:28:49]Let's see what kind of amps we're using right now.

[00:28:54]So currently 45 45 47.

[00:29:10]Beautiful.

[00:29:13]All right. Well, I would call that a successful loss of utility um buffer gen start transfer. Now, what I want to see is if the utility is restored, um does it immediately switch back or does it wait for the pump to finish? It should wait for the pump to finish because during that switch back, the pump is going to be slammed off and on.

[00:29:43]So, we're going to simulate power was out for a couple hours, there was a call. Basically, the the worst case scenario would be the power goes out and then is restored during a call. Because if the power is out and there's no call for water and then it comes back on, nothing in here has changed. So, let's simulate that. I'm going to go turn the utility source back on.

[00:30:08]Okay, the utility source is back on.

[00:30:14]Yeah, it shows source one available, but it also shows a return inhibit. And that's because of our control wiring here that prevents it returning to the source until our controls say it's okay to do so. And our controls will say that when there's no longer a call for the pump. So, I'm going to go simulate the demand for water ending by turning the pump off or the call for the pump. And we should either see a delay and then a transfer or an immediate transfer. Let's see.

[00:31:02]Pretty immediate.

[00:31:07]Almost too immediate.

[00:31:10]Um, but we can let that slide. It should be transferring back in about 13 seconds.

[00:31:17]So, as soon as the call was removed, the generator enable was removed.

[00:31:23]And that was it.

[00:31:28]Not the smoothest thing in the world.

[00:31:30]And there it goes back to utility.

[00:31:36]I don't know if that's the smoothest thing in the world, but um seems to be functional. Um there's no real ramp down. As soon as the call is removed, it just pulls power from it and it'll coast to stop.

[00:31:51]I suppose that's not the end of the world.

[00:31:56]Yeah. Yeah, I think that'll work. I'll review that with the team and uh with the operator and make sure everybody's on board with that before I make phone calls and start trying to change things that other people have put a lot of time into. Um otherwise I'd say it's successful. It detects a loss of utility. It waits until there's a call for water. It starts the gen, runs it, and then it doesn't um shut off the gen until the call is removed. Uh, as soon as the call is removed, the gen shuts off with no cooldown time.

[00:32:31]There should be a cool down time. Yeah.

[00:32:35]Yeah, we should talk about that. So, I'll talk with the guys and we can look at making some programming changes because Yeah, we we should have some kind of cool down time at the end. Let the generator idle for about five minutes um after being under load before it just cuts it out. All right.

[00:32:55]Otherwise, my scope for today, getting this switch installed, I would say, is mission accomplished. Everything else seems functional and good. We can put the site back in automatic. And uh yeah, I'll see you guys on the next one.

[00:33:08]Thanks for watching.