Looking for URD help

[Line_Man.]

Havent got a chance to get the cableman's hand book so I was just wondering if anyone knows any good site I could read up on. I'm back in miserable FL and just need some literature to read to stay busy :D Thanks in advance

[rcdallas]

What are you looking for in underground? Terminating cables?

Underground will carry a capacitive charge...you deenergize the cable and go to replace a elbow or whatever, you best touch ground or ground at another point. You'll hear it pop when you do.

Another thing to think about is Ferroresonance on 3 phase padmounts, if the length of the cable exceeds the KVA of the transformer you'll more then likely blow your arrestors if you don't have a light load on the transformer OR open the switch up.

[Line_Man.]

Good insight dallas, stuff like that is what I'm looking for. I haven't had much experience with URD I have mainly done overhead and recently seen that I need some URD knowledge to be pleasing to the utility I'm trying to get on with and would just like to know some tricks when it comes to underground. How about troubleshooting tips? I havent done any URD troubleshooting other than the switch is open at the road:p

[Trbl639]

As far as ferro goes on 3 phase pads...we always dumped the customer load, then killed the pad, then opened the UG primary to the pad....then went back just the opposite........usually didn't have blown arrestors or burn the pot or cable....but it has and will happen.........

Troubleshooting UG can be tricky.......busted a many a cap on a single pahse dip...then isolated between pads till we found the bad run....most utilities now have the (some still don't) little LED lights tied to the primary at the pads to tell ya where the bad run is, most have got the radar/thumpers, that can shoot the fault thru padmounts then it gives ya a distance, then when ya get to where you think you're close, then thump it...........lots of new fangled stuff out there for t-shooting UG now days...

[TresAmigos]

Here as im sure other places, you must ground at each work location..both ends of the wire, that is after ofcourse you have identifed, isolated, test de energized...and now you can ground. As far as ferroressonance, if you follow step wise switching you should be ok, or open the breaker. As far as terminating urd...either get with some guys who work for the co, maybe if they have a standards book you can borrow or look at the specs online. We have our own standard more or less to leave room for a fi. Elastimold, Thomas & Betts, Raychem, 3M are some good places to start Good Luck

[rcdallas]

You could end up rolling to change out a failed pad mount older style with no bayonet fuse. Troubleman says it's just a bad padmount. So your crew changes it, an hour later it blows the bayonet fuse on your newly installed one.

Troubleman didn't check for a secondary fault.

Pull all the meters off. Take loose the secondary buss bars, check for resistance between X1 and X2, shows 0 ohms. Now check between X2 and X3, you see resistance, now pull each hot leg out of the buss bar individually and start checking each one until you find resistance on the specific hot leg.

On a CT/PT meterbase you must disconnect the PT's or it will show resistance.

[Edge]

Havent got a chance to get the cableman's hand book so I was just wondering if anyone knows any good site I could read up on. I'm back in miserable FL and just need some literature to read to stay busy :D Thanks in advance

Send Hemi a PM... I'm sure he's gotten an 11th edition by now.. I sent him a 9th or 10th a few years ago...

if he's got a new one I'm sure he'll pass it on as long as you promise to do the same...

Edge

[Line_Man.]

Thanks edge. Just wondering is there a big difference between the editions? I found the 11th for like $55 and I just got a nice OT check so I was going to buy it.

Also, thanks dallas for a little troubleshootin on the UG :) Always useful tips on the wire you cant see haha

[Edge]

yeah there is...

55 is a good deal... I'd get it if I were you...

I haven't picked one up yet or I'd send ya one...

Edge

[Line_Man.]

http://www.superbookdeals.com/cgi-bin/cart.cgi?item=4238846

best deal i have found

[wtdoor67]

You can much cheaper prices on the Kurtz book from Barnes and Noble, or Amazon I believe. Just look in their used book part. A 6th edition is fine I think. Many of the editions are much the same. Very little changes with the basics.

On the URD don't try and BS the power co. about your knowledge of it. Just tell them the straight. It's okay to just have a basic knowledge I believe.

If you already know some of the things I relate, well just bear with me. Single phase URD with most companies of course is built with a single conductor wire with the concentric, stranded wire on the outside acting as the neutral. The only URD I have ever experienced was all Wye system. I'm sure there's some delta URD out there but I've never experienced it. A run of wire without a loop is called a radial. With a loop one transformer is designated the NO (normal open) and one elbow is stood off on an insulated bushing stand and fed from the other direction. On trouble after the bad run is found then it's put together at the NO and then hopefully everybody is back on. Some co's use fault indicators which show an indication if fault current has run thru them. When you open padmts and see indicators then you just keep lifting lids until you don't get an indicator. If there's no indicator then you've passed the fault and it's in the run behind you.

Dead front is the term used to discribe those pdmts that use insulated elbows for terminations. Most deadfronts have bushings designated H1 A and H1 B. Both of these bushings feed from the same bus. Live front pdmts have primary bushings that are uncovered. Most of these are in older installations of single phase. Most co's require rubber gloves when opening any padmt. You can't always guess what you'll see when you open them. Secondary bushings are mostly uncovered. Some co's get covered ones, some don't. The secondary bushings are at a slight angle and the neutral bushing is on the bottom unlike an overhead pot, so they're X3, X1 and X2 on the bottom. Most co's use 25 KVA's and up. Some start at 50 KVA and up. Just depends on their engineering practices.

Most of the secondary is alum of 1/0 and on up. Most have a reduced neutral. There's a lot of smaller and a lot of larger than 1/0 secondary.

3 phase pots are almost always 277/480 and 120/208. There are other applications out there but these are the majority.

Tell you what. Get a Kurtz book. I'm tired of typing this. Next time you're around the pwr co. guys bum the instructions for elbow and splice kits that come with them and have a look. It'll probably clear up some of it for you.

There's lots of other things but you probably ought to experience them. It's all pretty easy for a good hand to pick up anyway.

[wtdoor67]

6th edition from $6.41 on up. Pretty cheap.

[Edge]

You can much cheaper prices on the Kurtz book from Barnes and Noble, or Amazon I believe. Just look in their used book part. A 6th edition is fine I think. Many of the editions are much the same. Very little changes with the basics.

On the URD don't try and BS the power co. about your knowledge of it. Just tell them the straight. It's okay to just have a basic knowledge I believe.

If you already know some of the things I relate, well just bear with me. Single phase URD with most companies of course is built with a single conductor wire with the concentric, stranded wire on the outside acting as the neutral. The only URD I have ever experienced was all Wye system. I'm sure there's some delta URD out there but I've never experienced it. A run of wire without a loop is called a radial. With a loop one transformer is designated the NO (normal open) and one elbow is stood off on an insulated bushing stand and fed from the other direction. On trouble after the bad run is found then it's put together at the NO and then hopefully everybody is back on. Some co's use fault indicators which show an indication if fault current has run thru them. When you open padmts and see indicators then you just keep lifting lids until you don't get an indicator. If there's no indicator then you've passed the fault and it's in the run behind you.

Dead front is the term used to discribe those pdmts that use insulated elbows for terminations. Most deadfronts have bushings designated H1 A and H1 B. Both of these bushings feed from the same bus. Live front pdmts have primary bushings that are uncovered. Most of these are in older installations of single phase. Most co's require rubber gloves when opening any padmt. You can't always guess what you'll see when you open them. Secondary bushings are mostly uncovered. Some co's get covered ones, some don't. The secondary bushings are at a slight angle and the neutral bushing is on the bottom unlike an overhead pot, so they're X3, X1 and X2 on the bottom. Most co's use 25 KVA's and up. Some start at 50 KVA and up. Just depends on their engineering practices.

Most of the secondary is alum of 1/0 and on up. Most have a reduced neutral. There's a lot of smaller and a lot of larger than 1/0 secondary.

3 phase pots are almost always 277/480 and 120/208. There are other applications out there but these are the majority.

Tell you what. Get a Kurtz book. I'm tired of typing this. Next time you're around the pwr co. guys bum the instructions for elbow and splice kits that come with them and have a look. It'll probably clear up some of it for you.

There's lots of other things but you probably ought to experience them. It's all pretty easy for a good hand to pick up anyway.


good stuff here 'door...

damned good stuff... and pretty much in key...

Kurtz book will prolly provide more info then the L&C bible will... but the part about dig up the papers from the local PC was solid..

and your right with good tools... underground is easy regardless of what system your working... hell most kits now a days have templates to idiot proof it...

and most Iou's build it to their max busition voltage... you running 4160... build the sob to 34.5 you running 12.4 build it to 34.5 you running 13.6 build the sob 34.5 it'll always work over built... never under.....

good shit 'door damned good...

Bill

[rcdallas]

We use S&C Switchgear...600 Amp

PMH-6 2 Solid Blades 1 set of fuses
PMH-8 1 Solid Blade tied 2 set of fuses
PMH-9 2 Solid Blades 2 sets of fuses
PMH-10 4 Sets of Solid Blades
PMH-11 3 Solid Blades 1 set of fuses
PMH-12 1 Solid Blade 3 sets of fuses
PMH-13 3 Sets of Solid blades

Diagrams to follow ?? :p

Never seen a non-load break fuse...I've been told "you'll know when you see one".

The ones I deal with have a ring when the fuse does blow.

The muffler is to prevent a phase to phase / phase to ground flash.

There is lots of other type of stuff, ATO's Automatic Throw Over's...basically a automated switch that will have a preferred / alternate feed. We have a few of them in our downtown. Ground fault switches...goes on an on.

Never seen an underground capacitor though...Anyone got a pic???

[Line_Man.]

Don't seem like im too far behind on the UD knowledge just have never got my hands on it as much as I wanted to.

And no I wouldn't lie about my knowledge because that just makes me look really really retarded when I'm sitting there dumb founded:D

I have made up a few potheads and helped change out some pads on a conversion (changing elbows and removing secondary buses) but I guess what I doubted myself in was troubleshooting because I can't see it!

Keep the knowledge coming though guys i really appreciate it

[wtdoor67]

I think mapping and marking are the most useful thing with it. With good maps and proper marking you can go in an unfamiliar area and sort it out. Without maps and marking, it's a big puzzle.

Of course always remember that maps and markings are no guarantee. Never trust them 100%. It's always that 1 % that gets you.

They have some really great locators made now. A person familiar with the tools being used can usually give you an accurate path of the cable run and give you the footage almost to the point of a fault. That stuff has sure evolved exponentially I have to say.

My first experience with faults was the old hunt and peck system. If it wasn't found by looking in the pots then we just sectionalized each run by standing it off and trying fuses untl we blew one. Then we put the thumper on it. Kinda crude.

Later got a chance URD phasing tool. It enabled you to locate the run without blowing fuses. Then the thumper of course.

The aforementioned was areas that didn't have fault indicators.

With fault indicators, the first I experienced didn't reset themselves. If a previous yahoo hadn't reset them then you had to go thru and reset them and then blow a fuse and lift lids and look. Then the thumper.

Eventually got some indicators that reset themselves. Just find the open fuse, decide if it were blown by a fault (no dead squirrel etc.) and lift lids and perhaps isolate the bad run.

On radials sometimes have run underground on the ground as my friend used to say. Just lay a piece of primary on the ground and bypass the bad spot until we could get the thumper on it. Frowned upon in some hi traffic areas though.

Eventually discovered the thumper hurt the wire pretty badly and caused trouble later.

The last I experienced was the fault locator that gave you the screen with the line running across it showing you the footing exactly to the fault. We would sometimes give it one thump to verify we were on it. Good tool. Expensive I understand.

On secondary never did much of that. Servicemen did them and got a backhoe sometimes to dig it up and fixed it themselves. Sometimes in easy digging they just shoveled it themselves. Hard core.