loadbuster failures

[dbh]

1946Has anyone been experiencing S&C Loadbuster failures? I have been a lineman for 28 years and have never seen anything like this before. I have talked to just about everyone I know and they have never heard of such a thing. The tool typically fails on 23kv system while breaking station ties between two stations fed by two different transmission voltages. I am on the joint safety committee and we are trying to convince the company it is a system issue and can be rectified by installing gang operated switches. They say it will cost too much. Most companies have gang operated witches in place for this type of switching. I have done a ton of research into excessive KVAR, re-strikes anf TRV's. I cannot find anything that is exact to our situation. Any experiences anyone hs had will help our side of the argument. Thanks

dbh

[wtdoor67]

You're supposed to clean them periodically. Had a rep come by once and take ours apart and clean them. I don't remember the criteria. I expect S & C would give you their recommendations.

They do get carboned up pretty bad. Most people don't clean them.

[BigClive]

Here's a link to an operational description of the unit:-

http://www.sandc.com/products/loadbuster/loadbuster_operation.asp

If there was a carbon buildup inside as mentioned by WTdoor then that could cause a sustained arc inside after the load was "broken" that could result in heat damage.

What sort of current is it being used to break?

[topgroove]

can you show us pictures of the switch pole or switch gear that this happened at. I'm not sure your getting the full story hear. was there burn marks on the switches or hardware. it looks as if the head of the load buster got between phases. i've seen it done.

[loadbreak55]

The only time that I've seen one of these tools fail was operator error!The lineman failed the fully "charge"it(making sure it was closed all the way).I never even thought about carbon build-up:eek:,thanks for the heads up,I'll bring it to the boss's attention.:D

[shaun]

I had a problem last week during some rain with the tool. (not like that guy though! WOW, never seen that before!!) Mine was more like, the loadbuster didn't snuff out the arc like it used to. Opened it up and it was white and clean inside so I chocked it up to me. Maybe, I didn't pull it all the way through when I opened it? But the next day I used it on 2 cutouts and had similar results. I know I operated it correct that time because it was fresh in my mind but still had a slight arc outside the tool. I went into the plant and got a new one. I explained what happened and they are testing it to see if the tool went bad or I screwed up. (In defense for the loadbuster, I never had a problem with any at all for the past 10 years I've used 'em)

[Daddyof2]

Only had a loadbust fail one time so far. It failed on the third switch of a cap bank on a 25kv system. Was told they need a minute or two to cool down between switches on a cap bank.

[500 KVA]

Cleaning and testing inner components is a must.

The loadbuster in the picture looks to me to be for up to 15 to 20 KV. Not certain of the upper voltage limit of the smaller one. They make a 35 KV loadbuster for anything over that 15 to 20 KV. You may have gotten away with using it on 23 KV for some time, but not for ever.

[markwho]

We have been using the S & C load busters for the past 30 yrs where I work and have never anything like that happen. We may have had some minor problems from time to time. If you suspect you are having some problems you can field test them with a continuity tester on your VOM to check for continuity in the closed position. Besides the carbon build up, there is a braided cu. wire formed in a spiral that moves like a spring that can fray and deteriorate over time and there by diminishing the load it can handle. They aren't that bad to disassemble following the instructions if you want to do a visual. Just be careful to lay everything out in the right order when disassembling. One tool that is useful is a set of snap ring pliers. I used to clean and repair them from time to time and replace parts that wear out. We stopped doing them ourselves and now send them out when we need to do maintenance. Newer units made after 1983 can be retrofitted with a special kit that includes a counter on the cap to keep track of the usage. I can't remember the exact numbers but they are good for about 1500 or so uses before maintenance is needed, sooner if you use them for breaking load closer to the limits. Take a look through your manual and you can find most of the info. You can send them to S & C for a rebuild. I called the company in N.Y. and they answered my questi0ons and directed me to a local rep. in our area. I had left a message and they got right back to me. Glad I wasn't on the end of that stick!

[dbh]

Thanks for all the responses. We have been working with S&C on this problem, it is a head scratcher for them as well. The tools are maintained annually and all maintenance is documented. This is a 25kv rated tool used on a 23kv system. The picture provided is just one of several tools that have failed repeatedly over the past ten years. The tool is being "cocked" and used correctly. The failures have occurred to several different operators, not just one. Usually happens while switching on 23kv (phase-phase) fed by two stations fed by two different transmission voltages. Since this is an ongoing concern the lineman usually inspect the 900 amp disconnect before operating.

[johnbellamy]

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[wtdoor67]

This happened in about 71 or 72. We contractors had installed a set of 600 amp underarm disconnects on a 24.9/14.4 line. The following week a power co. hand was attempting to clear a section of the line. I don't recall the sequence, but at least one disconnect was ruined during the opening.

The explanation from the power co. was failure to clear a set of capacitors that were about 2 spans away. No load buster was being used and there was no load on the line the best I remember.

Once in awhile things happen in which there's not a plausible explanation.

Ferroresonance? I don't know. I remember we went and replaced the disconnects.

[dbh]

Hey John,

Thanks for taking the time to ask the questions. I will try to answer them the best I can:
1. The substations are equipped with individual regulators. They are always addressed in every switching order. Zero and off or same step and off.
2. This happens as part of a routine switching order. When the switches are first installed or any changes are made the switches are always hot phased. The tool fails breaking the station tie.
3. There has been failures on all three switches. The photo that is attached to the original posting failed on the first switch. I believe that the tool starts to break down on previous switching steps before the tool actually shows the failure. Some of the testing S&C has done show burns on the inside tube of the tool. Those tools were taken out of service because of heavy sparking. If left in service they may have had catastrophic failure.
4. The transmission voltages that the tool typically fails on are 140kv and 238kv.
5. The tools failure usually extinquishes the arc usually without locking out the feeder.
6. Usually just the load buster is damaged. Sometimes the switch has to be replaced because of carbon and splatter buildup.
7. The switches are visually inspected. The switching is done by one person performing routine switching or switching to isolate a section of feeder. Macking the switch is not always practical and the tools failure is always random and difficult to duplicate.

[johnbellamy]

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[BigClive]

Any idea what sort of current the unit is actually breaking when it fails?

[Koga]

one instance of one failling with me. But at the time it was being used on a single phase lateral disconnect. There is no dought in my mind it was used correctly , the **** thing just gave up in that split second. Still aint figured out why. Just be sure and operate em from a safe distance below and you should come out OK.

[Koga]

untieing 2 stations with different trans voltages, we had to make sure the taps were as close as possible at the stations involved. Haven't had that problem in a while I'll have to check and see exactly how they fixed it.

Koga

[CPOPE]

The load buster is a good tool but everything goes South eventually/

Use a big stick and expect it to flashover/Keep the tool clean and maintianed. In the case and not bouncing around in the till. It would concern me if this was a new tool with a limited number of operations. Again don't trust the tool or device being switched. PPE and distance will save ur arse/

Operating Life
Loadbuster is a sturdy and reliable tool that will provide years of excellent service. Only a minimum of attention is required to keep it in top-notch operating condition. Inspection intervals are dictated by the number of operations— as indicated on the operation counter—and the severity of switching duties. Aside from the counter reading, there are no audible or visible signals to indicate the need for attention.

From 1,500 to 2,000 Loadbuster operations may normally be expected between required inspections, based on typical usage involving a mixture of varied switching duties. Included in these duties are switching of line-charging currents, transformer-magnetizing currents, pole-top capacitor-bank currents, and moderate parallel or loop load currents, with only occasional switching of heavier load currents. Only if Loadbuster is used primarily for switching of load currents approaching the rating of the tool will more frequent inspections be required.
Benchmarks indicating the need for replacement of Loadbuster parts include the degree of erosion of the trailer portion of the moving contact assembly and the condition of its flexible cable. The simplicity of Loadbuster inspection and the ease of parts replacement are described in Loadbuster Instruction Sheet 811-505.
http://www.sandc.com/edocs_pdfs/EDOC_001525.pdf
Limitations on Use
1. Loadbusters must be used only with disconnects, cutouts, power fuses, fuse limiters, or dropout reclosers which meet S&C’s applicable minimum construction specifications found in the current revision of Data Bulletin 811-60.

2. Loadbuster Catalog Number 5400R3, rated 25/34.5 kV, must not be used with metal-enclosed switchgear, metal-enclosed switches or fuses, or pad-mounted gear, of any make.

3. Although the interrupting ratings of Loadbuster Catalog Number 5400R3, rated 25/34.5 kV, are equally applicable at lower voltages, it must not be used with the following devices, since the fuse tube or blade travel of such devices is too short to accommodate Loadbuster’s operating stroke:
(a) Cutouts, power fuses, fuse limiters, or dropout reclosers of any make, rated 110 kV BIL or less;
(b) Disconnects, cutouts, power fuses, fuse limiters, or dropout reclosers of any make, rated 7.2/14.4 kV, 7.8/13.8 kV, 8.25 kV, or less;
(c) Disconnects of any make, rated 125 kV BIL or less;
(d) Discontinued Station Style S&C Type XS Fuse Cutout Catalog Number 189131 (with or without catalog number supplements).

4. Loadbuster must not be used in applications where maximum system operating voltage exceeds the Loadbuster’s maximum voltage rating.

http://www.sandc.com/products/loadbuster/loadbuster_pubs.asp

[Koga]

GOAB switches was the fix. Sure beats the jerk and run method.


Koga

[Meat]

A new operation counter feature — available at no additional charge — lets Loadbuster users monitor the use of their tools . . . thus helping them make more informed decisions with regard to inspection and maintenance. The non-resettable operation counter is built into Loadbuster’s silencer, and can easily be added to existing tools during routine maintenance checks.

In addition to the operation counter, Loadbuster Tools also feature redesigned internal components for enhanced operating life — now 1500 to 2000 “mixed-duty” operations between inspection and maintenance. (Previously, inspection and maintenance were recommended after 500 to 1000 operations.) The term mixed duty refers to a mixture of line charging currents, distribution-transformer-magnetizing currents, pole-top capacitor bank currents, and moderate parallel or loop load currents, with occasional switching of heavier load currents.

Good info on this thread.I've learned quite a bit.Meat.

[Edge]

Hey John,

Thanks for taking the time to ask the questions. I will try to answer them the best I can:
1. The substations are equipped with individual regulators. They are always addressed in every switching order. Zero and off or same step and off.
2. This happens as part of a routine switching order. When the switches are first installed or any changes are made the switches are always hot phased. The tool fails breaking the station tie.
3. There has been failures on all three switches. The photo that is attached to the original posting failed on the first switch. I believe that the tool starts to break down on previous switching steps before the tool actually shows the failure. Some of the testing S&C has done show burns on the inside tube of the tool. Those tools were taken out of service because of heavy sparking. If left in service they may have had catastrophic failure.
4. The transmission voltages that the tool typically fails on are 140kv and 238kv.
5. The tools failure usually extinquishes the arc usually without locking out the feeder.
6. Usually just the load buster is damaged. Sometimes the switch has to be replaced because of carbon and splatter buildup.
7. The switches are visually inspected. The switching is done by one person performing routine switching or switching to isolate a section of feeder. Macking the switch is not always practical and the tools failure is always random and difficult to duplicate.

Hey bra... I don't wnat to talk away any thing JB said all thats some solid advice... but if I understand you scanario correctly your breaking a "hot tye" between to feeders that are shareing load...

If youre zeroing in the regulators at the station then that very well could be where your fuggin up.... a GOAB (with arcing horns of course or preferable Airbreak) is the answer...

you see the different trans voltages feeding it isn't the problem (not imho anyway) and in fact aint got **** to do with it... alot of folks think that if it phases it's good not always the case... lay you phasein stinks across the leads on a regulator thats at step 8 and you'll get the same the same phase but you got to different voltages... you gonna bypass that ***** cuz the phase sticks say 0? lay the bull horns across and you see the step due to voltage (buck or boost) and there in lies your problem I think...

If your regulators are set to 0 on both feeders and you open the gate whatever the actutally voltage of the feeder lines ACTUALLY is when thier seperates trys to correct it's self and you end up bucking voltage... just like you would trying to by pass that regulator on step 8...

if this is what your saying then a better solution is the goab... some places even try to keep records of their hot tye switching as to last can on the feeder voltages and step the regulators at the station accordingly to hot tye or split tye...

I ain't sure I explained that worth a fuggin dime or if thats even what your explainin but take it for what it's worth!!!

Be safe,

Edge

to old to not climb it!

[wtdoor67]

Most of the time when paralleling or breaking parallel of feeders I have seen the regulators matched (the voltage) and locked down. Same with LTC's. If the switching required opening or closing one phase at a time the the ground relays were disabled also. I asked a meter relay man once about why some co's disabled the ground relays in this operation and he said it just depended on their relaying scheme.

When I worked for John's co. they were fond of using load break cutouts on a lot of applications. I thought this was a good practice as I can't recall using Load Busters at all there.

As Edge says I never thought the transmission voltage source of various feeders made any difference.

[johnbellamy]

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[johnbellamy]

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[johnbellamy]

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[johnbellamy]

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[johnbellamy]

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[wtdoor67]

Yeah John, the angel wing, elephant ear load breaks were the ones they used. I to, liked them. The only fault I found with them was not pulling the fuse down hard when you put it in the barrel. Done improperly it would uncock just enough to make a small load arc that would heat up and melt that plastic which would fall in the grass and start a fire.

Is that your service truck in that picture? The trucks were mostly yellow and green when I was there. Someone called them yellow and George Nostrant (what a turd) said. That's not yellow, it's Pacific gold and Oregon green.

[johnbellamy]

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[johnbellamy]

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[CPOPE]

Excellent Post John, you are a scrapper

Although you might have me a bit wrong. My primary responsibility is not to protect the company but the craftworker. I do have a obsession for maintaining a safe work environment and that’s done by focusing on the accidents and learning from past mistakes. Take your eye off the ball and compliancy can kill. As an industry we loose about 50 guys a year that way.

I do work as a standards engineer at a utility and as an independent consultant. I maintain my OH & UG T&D qualifications but I never said I was a good journeyman and dont think I was. I used to think PPE was just for fags and I could rule the world. Now I know better.

Believe it or not brother, If I can call you that. I think we are on the same side.

I wanted to be an engineer for alot of reasons but HH said it best.
"Engineering is a great profession. There is the satisfaction of watching a figment of the imagination emerge through the aid of science to a plan on paper. Then it moves to realisation in stone or metal or energy. Then it brings homes to men or women. Then it elevates the standard of living and adds to the comforts of life. This is the engineer's high privilege.

The great liability of the engineer compared to men of other professions is that his works are out in the open where all can see them. His acts, step by step, are in hard substance. He cannot bury his mistakes in the grave like the doctors. He cannot argue them into thin air or blame the judge like the lawyers. He cannot, like the architects, cover his failures with trees and vines. He cannot, like the politicians, screen his sort-comings by blaming his opponents and hope the people will forget. The engineer simply cannot deny he did it. If his works do not work, he is ****ed." \\Herbert Hoover

[BigClive]

That is not my service truck, but looking at that picture, if you go down the road aways, turn left and cross the tracks, you will see it, 66 Balm st is where I is dwellin, use Clives satelite link and you will see it, let me know and when ya look, I believe you will see a full moom out tonite.


Actually there's not a lot of data on your area yet...

http://maps.google.co.uk/maps?f=q&source=s_q&hl=en&geocode=&q=66+Balm+st+touchet&sll=53.800651,-4.064941&sspn=13.074846,28.300781&ie=UTF8&ll=46.039243,-118.674531&spn=0.003746,0.006909&t=h&z=17

[johnbellamy]

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[johnbellamy]

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[CPOPE]

[QUOTE=johnbellamy;62566
DBH, started this thread, he has a problem, and he already had his solution, I don't see anybody disagree'in with him here, his company is the problem, not the lineman, not the loadbust, it is a reaccuring problem, what ever the circumstances are, the gang operated airbreak switch would make the situation a safer one for the guy's in the field.[/QUOTE]

John if you think PPE is just for faggots than I truly feel sorry 4U
Please don't get me wrong but you seem a bit overconfident.

We can not put a gang operated switch at every switching point.
I do agree it is safer. If and only if you are wearing your gloves and dielectric footwear if operating from the ground or grade. Great if the loadbreak is hoohstick or operated from a bucket. Switch handels acessable to the public have been a vandelisim problem 4 me.

Thats right, this is also a business and simply put the cost of putting up a loadbreak switch at every switching point makes is cost prohibitive. A set of solid blades every 2500KVA connected with normal switching points. 1 out of 3or4 gang orpeated is typical. I'm in contact with other Utilities Standards Engineers across the country through the Edison Electric Institute and no company can afford to use GAOB's everywhere.

THere have been accidents with GAOB's
If the handel is at grade level on a GAOB step potential is a real problem.
Have you ever had a GAOB flash over? Have you ever had a loadbuster flash over? I got a flashed over loadbuster sittin at my desk right now and a second defective one after we checked the platforms.

I want answers from S&C and I ain't getting them. I don't need your bull**** or telling me how to run my shop. You proabably spend most of your time on a digger truck leaning your fat arse against the tailboard complaining. Don't need your union/management bull****.

Yours truley "The Reaper" more cowbell please

[johnbellamy]

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