Locating HV Cables with a Genny and CAT

0:02HV cables, guys. HV are the hardest cables to detect. Again, guys, it's a short mini session. I can't go into all the reasons why that we do in the full course. Typically speaking, you guys might have experienced this. You tend to get stronger power signals off LV than you do off HV. HV is normally deeper. The biggest issue with HV is where can we connect a journey to it for most of us guys that can't get in in subs? Yeah, Joe. Absolutely. um semi-cable TV is being shell. Um so we we can't connect onto it. Um so the only option we've got with HV a lot of the time is is induction. It's

0:38the only option we've got. But the problem is this guys, look at this footpath LV HV deeper. Yeah. So even when the genies here, can you see what's going to happen? We end up lighting this thing up. So that's why it can be very tricky with HV sometimes. So what we do is this guys, this is back to that UKPN drawing. So remember on this guys, the green is LB, the red's HB. We're proposing to excavate here. The cat only finds the LB. No matter where I put this Genny, I only find the LB. All these examples are show I'm showing you guys worked here

1:11and done this. Okay, so the real basically so we can't pick it up. So what we do like before, we zoom out. Let's have a look. What we can see over here is the separation. If I apply my Genny signal here onto the HV, I can now locate it back down here. That make sense, guys? Because the LV is not kind of blocking it if you like anymore. So, what we try and do with HV, I know you can't always do this is try and find a bit of separation, maybe a road crossing or something like that. Again, guys, I hope I hope hope you're okay

1:41with that. That makes sense. Same here, guys. Excavating here, we we induce here. What I often do guys is do HV last. It's very tempting to think, oh, we got HV, we'll do it first. But do it last because, and the reason for that is simple. You've already got stuff marked up. So if you do accidentally induce onto another utility, you know you've done it because you're picking up the same thing again. You see what I mean? Okay. You all happy so far, guys? All making sense? I hope. Any questions? Okay. Next question I want to ask you guys is, um, have you heard of a twoman

2:14sweep before? Twoman parallel cat and Genny sweep. Have you heard of one? I want to know if have you been trained to do that or have you done it? Is it something that you do? Give me some feedback on that and we'll have a discussion about that. While you answering that question, guys, I want to show you something. Wait, I'm going to put my full video thing up there for a minute, guys. Um, hello. When you're when you're using a locator on induction, you know, you've got to be 10 meters away from the transmitter. Um, just going to jump up for a second while I show you this.

2:46Hopefully you can still hear me. Even even when you're even when you're 10 meters from the transmitter, you can still pick up a direct signal to the locator. So quite often what happens is your gen is 10 meters away. There is actually no utility there, but the CAT's still giving you a signal or your locator's still giving you a signal. And it looks just like a a cable as well. You'll move it backwards and forwards and it'll look just like a signal, but it's actually airborne. So one of the things I want to quickly show you is how you test for that. So, if you imagine

3:16that I'm stood here with my locator and my T is 10 meters away that way and I'm getting a signal. I'm thinking to myself, is that signal coming from an underground utility or is it coming directly from the transmitter? And the simple way to tell is by lifting the locator and pointing it towards the transmitter. If I lift and my signal increases, it's coming from the transmitter. If I lift and my signal decreases, it's coming from underground. And that's a very simple way how you can tell where your signal is coming from. Okay guys, so we're we're we're getting um we're getting kind of towards the end

3:58of our survey now. We've done all our connecting and stuff, aren't we? And clamping and things. So, this is where we talk about the kind of final induction techniques. And the reason I brought up the twoman sweep is I know a lot of people have been taught to do this. And I have some concerns with it. It's a technique that's still being taught and I think we just have to be careful. First of all, for anyone that doesn't know, let me explain what one is. Still using induction. If you imagine that I've got a footpath here and I've got my excavation here. Okay. The idea of a twoman sweep is the

4:31the the CAT is here if you like and the Genny's here. So, I've got somebody with the CAT and somebody with the Genny. And the idea is at the same time they walk together across. So, you imagine them both walking together. And the idea is that if there's anything coming across here, they'll hit it at the same time. Okay? Hopefully that makes sense, guys. Now, the problem with this is that I wouldn't recommend doing it in a footpath or a carriageway. And let me explain why. It's not bad for road crossings, I guess, and stuff, but what we could potentially have in a footpath is a

5:06cable that does that. And that's not uncommon, guys. You know, it's changing position in the foot path. You imagine you're here with your CAT and your Genny's here and you walk across at the same time. In the in the starting position, the CAT isn't going to detect it because the Genny's not on it. Then you walk together, but by the time the Genny's on it, the CAT's not. You see that? Okay. So, that's that's that's one of the potential downfalls of a twoman sweep is that if a cable changes position between the CAT and the Genny, you can miss it. You see? So, the technique that I teach people to do is

5:42is what's called a blind induction sweep. We're going to come to that shortly, Joe. Um, hang on. Have a look at the picture there, guys, or the six pictures. Uh, you'll see that the Genny's in a different position on each one of the six pictures. So, what I want you to do is just kind of keep that in your head if you like. just memorize that picture and then let's transfer it to the to the real world. If if that's my footpath again, now this could be a carriageway, guys. I keep using footpath, but it could be a carriageway. Doesn't matter. That's the bit that I'm interested in. I'm going to

6:20go 10 meters away because that's how far away my Genny has to be. And I put the Genny over the curb with a handle like that. And I scan across. Then I put the Genny here and scan. Then here and scan. If you think about the pictures before you here, scan here and scan it. It effectively does exactly the same thing as a twoman speed. But what it does do, it accounts for anything that doesn't run straight. Because as long as I scan the whole width of that on each Genny position, even if a cable runs diagonally, I'm still going to find it. Just give me some feedback on that. Does

6:52that make sense? And you can see the difference between that and the two by one. 2x1's good for big areas, but foot pass carriageways. I tend to think I call it a blind induction sweep. Some people call it footprint sweep or something, but that's what I I think is is a is a better way in that situation. Let's just finish off then talking about our method that we talked about. Do you remember we did seems like ages ago now? We did the lighting, we did the LV services, the L mains, the coms, we've done pipes. You know, we're locating all these things one at a time. And this is

7:22the kind of the last thing that we do. Um the final thing that I does the orientation of the journey to the direction of service have any effect? Yes. Um Luke, it's got to be in line with it. So the handle of the Genny has to be in line with the the utility. Roughly though, 45 degrees, you'll still be fine. Okay. Yeah. So yeah, roughly handle in line. Yeah. I think what I think I think what you're getting is if it's running diagonally under the Genny, will you still get it? And yeah, you you will. It's it's not bang on in line. The final thing we can do with the

7:59Genny, guys, is no. And I think this is what somebody was referring to before about putting it on it on it on its side. Um there's many many reasons why we know that guys. Um I I can't go through all of them again, but I'm going to give you one example. Do you remember we talked about the HV situation that we had before? And you remember we said we had the LV here and the HV here. Okay, possibly something else here, but that's our HP. And can you see that no matter where I put the Genny, I can't get signal on this, it's either going to

8:30be hitting that or it's going to be hitting that. Yeah. So, our plans are telling us there's HV there. Okay. Um, but we can't find it. We We've tried passive molds. We've tried induction. Can't find it. This could be. Now, this is what I was talking before, guys, about well, you might want to look at your plans now and find some separation. Do you remember we talked about that just a little while ago? But let's say you can't. Your plans are showing you that the HV and the LV are together all the way up that foot path. So, what you might want to try is

8:58nulling out the LV. Look at the signal on the Genny on either side. You can see that dead zone there. If I tip the Genny on its side like this, I've now got that, haven't I? Make sense? So, if I put the Genny on it side over the LV main, the one the one I keep finding, the one I don't want to find anymore, it's blocking everything else, it cancels that out and throw signal down and hopefully lights up the um the HV for you. So, that's um yeah, that's why we know and how we know, guys. Oops. Guys, there you go. That was my session

9:40on how to get the best out of the Genny. I hope it was worthwhile. Um, has anyone got any questions or anything else you'd like me to expand on to? I'm not in a rush to get off at the minute. So, if there's anything you want me to cover while I'm here, I will do. Give me some feedback, guys. Was it all right? Do did the software look all right? Was the content okay and stuff? Let me know what you thought. I hope it was a useful use of um what we've been just over an hour and stuff. So, it wasn't a waste of your time.

10:27Thanks, guys. Yeah, always Allison. Catch you later. Thanks, Tom. Thanks, Phil. Cheers. Uh what's Luke saying? Any advice for a fencing contractor working at two or three different small sites a week? Sourcing drawings isn't always easy. Uh Luke, drop me an email. Probably be easier. We have a natter about that so I can get exactly what you're going going on about. Send me an email. I'm quite happy to give you a ring, Luke, and have have a chat with you. Thanks, Jay. Thanks for the feedback. Cheers, David. Thanks, Brian. I don't think there's any questions coming in, guys. So, um, if it's okay with you, I'm going to go and have a

11:35little tinkle. I have got another one coming up, I think, at one. Is it one or half one? Can't remember. Don't know if anybody else is in here is on that one. It's the last one I'm doing and we're going to be having a chat about power radio and just um some of the problems if you rely too much on passive modes. You can probably tell I'm a massive fan of the Jenning. Okay. So, so yeah, if you're on that one at one, I'll see you then, guys. If not, I'm going to turn my video off now, guys. Um, thanks again and I'll catch you later.

12:13Uh, Brian, I'm still here. Earththing problems. Um, not sure what you mean. Again, Brian, just drop us an email if you wanted to just go into anything a bit more detail. I'm going to have to shake because I'm desperate for the toilet now, guys. So, I'll catch you later.