Feeder Trips

[wtdoor67]

If this was an actual happening, what happened?

Yeah small fuse don't always work.

[Divemaster]

Over ten years ago, before we had our Fault Wizard, we had a call on a 120/240 bank in a transclosure fed off a 12470 circuit with old non jacketed cable. The supervisor had us disconnect the bank, checked continuity and it was ok. He closed the fuses and they held so he had us just change all three transformers. When he closed the cutouts: wham same fuse as before blew. We isolated the bad phase and wired it to an open bank (good thing the XFs were way oversized) and we got the customer by till new underground was buried. Haven't had that happen since and he couldn't ever remember having that happen to him before. After we got our fault wizard, I went back, isolated both ends of the cable and high potted it and sure as s**t it was bad. Now it's my spot for training others how to use the wizard.

[MI-Lineman]

Over ten years ago, before we had our Fault Wizard, we had a call on a 120/240 bank in a transclosure fed off a 12470 circuit with old non jacketed cable. The supervisor had us disconnect the bank, checked continuity and it was ok. He closed the fuses and they held so he had us just change all three transformers. When he closed the cutouts: wham same fuse as before blew. We isolated the bad phase and wired it to an open bank (good thing the XFs were way oversized) and we got the customer by till new underground was buried. Haven't had that happen since and he couldn't ever remember having that happen to him before. After we got our fault wizard, I went back, isolated both ends of the cable and high potted it and sure as s**t it was bad. Now it's my spot for training others how to use the wizard.

You checked continuity on the wire to see if it was bad with what? Some testers wouldn't push past 25 ohms or more so you'd get a false idea the wire was good cuz it didn't beep or did you have some kinda fandangled tester? Just wonderin cuz some here used to rely on that for checkin urd? The newer testers claim they'll tone out on high resistance faults but I don't trust it? The "fault wizard" another high pot adapter for sticks or is it a thumper option?

Just wonderin?

[Boomer gone soft]

Over ten years ago, before we had our Fault Wizard, we had a call on a 120/240 bank in a transclosure fed off a 12470 circuit with old non jacketed cable. The supervisor had us disconnect the bank, checked continuity and it was ok. He closed the fuses and they held so he had us just change all three transformers. When he closed the cutouts: wham same fuse as before blew. We isolated the bad phase and wired it to an open bank (good thing the XFs were way oversized) and we got the customer by till new underground was buried. Haven't had that happen since and he couldn't ever remember having that happen to him before. After we got our fault wizard, I went back, isolated both ends of the cable and high potted it and sure as s**t it was bad. Now it's my spot for training others how to use the wizard.

A little off-topic, Dive, but I gotta know...

Did you mean your supervisor was literally closing the doors, or he had you guys do it?

[rcdallas]

If this was an actual happening, what happened?

Yeah small fuse don't always work.

Turned out it was an actual fault. Located, dug up, repaired.

I guess my rudimentary method might only be used at po-dunk electric.

Preciate all the info!

[Divemaster]

As for ohming out the cable, we just used the a typical Fluke clamp-on. As for the 'Fault Wizard', it's a small portable unit that can thump or high-pot urd cables along with having a low voltage tdr. I can only crank it up to 12 kv and it doesn't put out the joules that an actual thumping unit puts out but so far it's worked on every fault we've had since we got it. As for the supervisor, yes he closed the cutouts. He's one of those that until a few years ago had the 'I'm God Attitude' and didn't trust anyone to do anything because nobody knew anything. Ten years ago I was still a greenhorn and I still think I am today even though I've learned alot on my own, from this site and also through experience. Best part is, now my supervisor looks up to me cause I know and understand how to use all of the up to date testing equipment we have that he can't even figure out how to turn on.

[MI-Lineman]

As for ohming out the cable, we just used the a typical Fluke clamp-on. As for the 'Fault Wizard', it's a small portable unit that can thump or high-pot urd cables along with having a low voltage tdr. I can only crank it up to 12 kv and it doesn't put out the joules that an actual thumping unit puts out but so far it's worked on every fault we've had since we got it. As for the supervisor, yes he closed the cutouts. He's one of those that until a few years ago had the 'I'm God Attitude' and didn't trust anyone to do anything because nobody knew anything. Ten years ago I was still a greenhorn and I still think I am today even though I've learned alot on my own, from this site and also through experience. Best part is, now my supervisor looks up to me cause I know and understand how to use all of the up to date testing equipment we have that he can't even figure out how to turn on.

So the Fault Wizzard's like a mini thumper? We use the Aquatronics amung other things. Never had "clamp on" Flukes here that I know of?

[Trbl639]

Normally we just dumped the load, isolated the phase that had blown and busted a cap on it...if it came back out, we thumped and repaired or replaced it......but we also checked the pot to be sure it wasn't bad too........We didn't have all the fancy test stools the guys are getting now!

[Divemaster]

Aquatronic equipment is excellent stuff in my mind. I've used their locators before and they seem to be right on. As for the Fluke: a typical clamp on digital multimeter. Nothing to high tech, the boss wouldn't go for it. I have to have help from a local manufactuing company to do FLIR pics for me because the boss doesn't understand the importance of finding hot spots on connections. The mfg. company does treat me good though, they even do ultrasounds on my substation transformers for me. Sometimes it pays to be in good with a big customer!

[Trbl639]

Aquatronic equipment is excellent stuff in my mind. I've used their locators before and they seem to be right on. As for the Fluke: a typical clamp on digital multimeter. Nothing to high tech, the boss wouldn't go for it. I have to have help from a local manufactuing company to do FLIR pics for me because the boss doesn't understand the importance of finding hot spots on connections. The mfg. company does treat me good though, they even do ultrasounds on my substation transformers for me. Sometimes it pays to be in good with a big customer!

Amen to that! Used to have an International Paper papermill in town.with a huge machine shop that was open 24/7/365........had stuff in a substa break...no Parts on hand except maybe in another state or the other end of the system...........those guys have machined and repaired stuff for us many times...especially when it was broke in the old Papermill sub!!