Another One......

[johnbellamy]

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[Lineman North Florida]

Had a wind storm, nothin major, got a trouble call, no power, 6 houses out.

I show up, single span off the main three phase gut, not fused, 7200/12470 wye, 50KVA pot, two bushing, not a CSP, fuse is in, jumper not broken on either the high or low side of the cut-out. Dead squirrel on the ground.

What is my problem? How would you trouble shoot it?
With 6 houses out I probably would tend to believe that it is really a no power call not just a customer tripped breaker that squirrel also would make me think that maybe he blew the fuse on the pot and the door did not open on the jack feeding the pot, but first if I knew that the breaker on the main line was in and as you said the top side and bottom side of the cutout feeding pot was not broken I would investigate that hard tied jumper feeding the lateral to see if I actually had primary voltage to the pot pole, if so check that barrel as stated before to see if fuse is blown and door failed to open if fuse was good I would probably be the dumb one and call for someone to bring me a pot:D

[wtdoor67]

If primary voltage is present, fuse is good and all connections on transformer are good, yes it's a bad pot. Did you leave out a clue John?

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Back at you John or anyone. Had a friend climb a transformer pole once on a no power. He was wearing leather gloves. Cutout still closed. Upon touching the pot case he was burned and fell to the ground. What happened?

[johnbellamy]

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[wtdoor67]

Single bushing pot with broken case ground. He was scorched on both hands but the fall to the ground broke his back. He made a full recovery.

Saw one once with a broken case ground. It would bob in the wind touching the case intermittently. Finally burned a hole thru the pot and leaked out all the oil.

[lewy]

That is why you should put some redundancy in your grounding connections. A lot of guys like to run 1 wire from H2 to case ground instead of separate connections. On a single bushing TX, X2 should have a ground strap & the lead should also be connected to your neutral, with separate connections for H2 & case ground as I said earlier. On a 2 bushing TX the only difference is you should also go from H2 to X2, some of the older 2 bushing TX do not have a ground strap.

[Lineman North Florida]

We ground 3 different points on our pots H2 to X2 to tank ground lug to pole ground, H2 to pole ground,and screw in 1 more tank ground lug to pole ground and we always bond 1 service neutral to neutral on the lateral or main line.

[Special ED]

I install the transformers H2 to pole ground. X2 to the tank ground I install right below it. And the tank is grounded by an additional lug installed near the bottom and goes to the pole ground. Pole ground is bonded to mainline neutral.

X2 is also tied to the system neutral. Lots of folks use split bolts on the grounds I prefer the copper h-taps. 301s I believe they are called. Split bolts vibrate loose over time and can be a death trap should a worker get between the open ground. All service neutrals goto mainline or to the 1/0 or 4/0 comming from x2 to main line.

Now the "pike" method I was taught comming up was H2 to case ground then to the pole ground. All one piece. Yeah its quick. But your bettin everything on one connection. They would also go X2 to neutral with whatever was available.

[jmorehouse24]

If any of you fellas hire on with Southern Cal Edison, you wont be grounding the xfrm tanks at all.

Have asked a few times why they don't ground the tanks here and have not got a real definite answer.

[rcdallas]

All we do here is H2 by itself to system neutral, case ground by itself to system neutral, pole ground to system neutral service busted onto neutral then up to x2.

I hear the standards changed where your supposed to install an additional case ground underneath the x2 and run that separate to system neutral.

One we've done a few times lately, on a deadend pole, we'll take the tail outside of the shoe and shape it up right into the x2... one less connection. One thing my foreman is serious about is to always squeeze onto the tail if available so when it burns up your line is still up.

Everything is squeezed on by itself, no 3 pieces of #6 shoved in one connector. :cool:

[johnbellamy]

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[johnbellamy]

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[wtdoor67]

It was 3 phase 34.5 to an oil field. The line double dead ended and belonged to the customer beyond the dead end. At this metering point was a gang KPF brand switch. A single phase pot at this location provided power to a Kyle at this point. The KPF switch was a backup to bypass the Kyle if needed.

Our illustrious foreman went out and made a half assed patrol on our part. It was deep snow. He reported nothing on our part and suggested the oil field have a close look at their own system. After being out about 2 days the electrician called me via phone and said he could find nothing and did I have any suggestions as what he could do at this point. He was a little perturbed.

I gave him a logical suggestion from a lineman view and he sorted it out. What would you have suggested? The information needed is in the foregoing statements. Don't over think it now. The electrician did have a small bucket I think.

Also all fuses and breakers were holding.

[wtdoor67]

John you better have this one quick.

Voltage complaint. At the pot the voltage is very good. At the meter point it is too low, with or without load. This is what I always referred to as a possible of 2 things. Service is good, no problem there.

[wtdoor67]

The source was 115 KV. The secondary at the sub. was 34.5 fed by the 115 KV. It was evidently single phasing. After checking everything I knew about in the sub. I went in the control house. The meter showed usuage on 2 phases but nothing on one phase. In retrospect I was probably lucky as the phase that supplied station service was still hot, so all instruments from station service worked.

I told the dispatcher there was an open on the 115 KV. He had a different theory. I finally overruled him and I started from the sub. end patroling and another hand started from the Dave Johnson (Power Plant) end. What evidently was wrong?

[wtdoor67]

Casper crew did some reroute work near Yellowcake sub. Can't remember what for. Anyway after they left the 3 phase Kyle on an outgoing 34.5 was left with the single phase transformer that supplied power to the Kyle was given a source that eminated from the load side of the Kyle itself. I will let you speculate what happened. After that I will Paul Harvey (the rest of the story).

[johnbellamy]

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[johnbellamy]

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[johnbellamy]

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[johnbellamy]

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[wtdoor67]

Just you and me I guess John. The first deal was a jumper had fallen out of a wave trap, not far from the power plant, there by leaving one phase dead not far from the power plant. This left the 115 KV only hot on 2 phases.

On the oil field problem the electrician had only a standard voltmeter. I told him to just bump the single phase pot from phase to phase via shotgun stick on the source side of the Kyle. This told him one phase wasn't coming in. He then called the dispatcher and told them to make a better patrol of PP's part of the line. A phase was found in the snow and fixed. Our foreman, what an Ace.

The no brainer, of course, wire size and distance. I've seen it quite a bit.


The (rest of the story) Kyle locked out on a transient fault of course and killed itself. The oncall hand Rose, went to the Kyle. He accertained that the Kyle was locked out. It had a gang switch (KPF) to bypass the Kyle with. He was too dumb to realize what had happened. He wanted to close the KPF but was afraid he would close into a fault. He then contacted Nauman (serviceman who didn't know how to run the rotation meter) and asked Nauman if he would come out, dump the sub. breaker, then he could close the KPF switch with the line dead and let Nauman pick it up via the sub. breaker. It was a weekend and Will Ward the supt. overheard the conversation as he was at the office in Casper. He said forget that, and ordered Rose to just close the KPF, which he did. The line was picked up via the KPF without incident. Monday we went out and moved the pot that served the Kyle to the source side of the line.

Here's more dumb stuff on this. The sub. was about 100yds from the Kyle. If Rose wanted to dump the breaker with his original idea, why didn't he just drive to the sub., dump the breaker, come back and then close the KPF, then return to the sub. and close the breaker? No, he wanted to call out an additional hand, have this man drive the 27 miles to the sub. and open the breaker for him. Talk about a hand!

They had some peaches there in Douglas.

[Lineman North Florida]

Regulator bank C phase reg stuck in 1 step raised needed to get it by-passed and get new regulator installed and old one to the shop to get worked on, regulators are reverse power flow and mainline has open tie point with another feeder on normal load side about 3 miles down the road,one more important clue there is a set of 600 amp blade switches about 6 spans from the regulator bank on the normal source side that are closed, how would you go about changing out the regulator without dropping the circuit? Keep in mind you cannot get regulator to neutral, I probably gave to many clues.

[wtdoor67]

I'm gonna say match it with the other line, lock em down and parallel them. Then bust open the solid blades after paralleling. Something like that.

I have about run out of scenarios and I believe there's enough people on this board to do a bunch. Come on turkeys.

[johnbellamy]

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[Lineman North Florida]

I have built many regulator banks and spent a fair amount of time doing maintenance on them ie swap out with new,so this went against everything that was ever beat into my head being told you cannot bypass reg if it is not zeroed out, seeing as how it was 1 step raised and hung up made it about as bad as it could get as far as I was concerned, I had already got the go-ahead to come in in the middle of the night and drop the circuit as I felt that it was the only safe and efficient way to by-pass bad reg and I had been pretty opinionated that that was how we would have to do it. I called a friend of mine whose opinion I hold in high regard and explained what we had and he said it could be done easily without dropping the circuit, here's what we did, I had a guy close the open set of switches about 3 miles down stream tying the circuits, had a guy set up at the normally closed switches that were 6 spans away and had him open them separating the 2 circuits at this time the reg bank is being fed from it's normal load side, there was no load now on the new load side because there were no customers in the 6 spans of wire between the reg bank and the open set of 600 amp switches. The moment of truth was hear I believed everything would work out ok but had never done this and I had never asked anyone to do anything that I had'nt or could'nt do, so I turned the regulator controls to manual turned the power to the controls off closed the bypass opened load side then opened source side of switch all without a hitch and no big fire, the key was no load on the load side of the regulator and having someone who knows what there talking about to get advice from.

[johnbellamy]

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[Lineman North Florida]

My Idea better;) Anyway, glad it worked out good for ya, I would have the guy show me it would work the first time, you had to have alot of things line up like they did for ya, I have seen them blow, they blow big, they ain't cheap either, let er buck, pardon the pun.:cool: Trust me I am not an advocate of steering away from the tried and true and I'm certainly not saying that I would recommend this in all instances, what I am saying is this was the perfect scenario for this to work out like it did and it has been done this way safely 2 times that I know of, I to have seen the damage that a regulator can do, mighty bad fire.