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View Full Version : Closing breaker on faulty feeder



byjuvc
10-07-2006, 11:09 AM
Friends,
I have seen a certain practice by our seniors. After patrolling a faulty feeder when they dont get any faults, they switch on the breaker. Usually it holds 90 times out of hundred but at other times it trips. The switching panels are having SF6 gas. The person who switches On the breaker does so keeping his face away from the panel. What are your comments to this practice from safety viewpoint ?


Byju

HighPotter
10-07-2006, 12:16 PM
Friends,
I have seen a certain practice by our seniors. After patrolling a faulty feeder when they dont get any faults, they switch on the breaker. Usually it holds 90 times out of hundred but at other times it trips. The switching panels are having SF6 gas. The person who switches On the breaker does so keeping his face away from the panel. What are your comments to this practice from safety viewpoint ?


Byju

What voltage is the feeder? They operate the breaker FROM the breaker?

There is NO way i would close a breaker, no matter the voltage , and especially after a fault, FROM the breaker.

Why can't you operate them remotely?

No way.

JAKE
10-07-2006, 01:41 PM
what we do is charge the breaker spring and operate the release to close the breaker with about 30' of rope on it.

HighPotter
10-07-2006, 02:04 PM
what we do is charge the breaker spring and operate the release to close the breaker with about 30' of rope on it.

Umm...ya. Thats one way of doing it.

JAKE
10-08-2006, 08:25 AM
i should further explain our method...

one 90% of gear is 7200/12470. a very little amount of 14.4/25

alot of the gear i had worked on military bases we were able to see what happened with the amperage on the computer to see if it was a long term overcurrent that tripped it or if it was a dead short.

normally under the dead short situation we would do alot more invesigation than an overload trip.

also all our gear is outside. dont have experince closing in a breaker inside after a fault. ive closed them in on a tested system inside but still have the rope on the acutator since non of thoose are remotely operatable.

still never operate them from right at the breaker no matter if its sf6, vac, or oil....

HighPotter
10-08-2006, 10:40 AM
What type and brand of CB are these?

byjuvc
10-08-2006, 12:27 PM
What type and brand of CB are these?

They are sf6 panels of ABB make having two isolators and two breakers (4 way). The breakers are spring charged first . Then there is a green button on the top portion of the panel. The lineman will stand on the side of the panel and not directly in front of the breaker which is being operated. Twice I have seen the breakers made ON without the fault really clearing and they trip the very instant of switching ON. At other times the fault clears (usually trees touching or some squirrel or bird) and the breaker holds.

Regards

Byju

"Principle without practice is useless and practice without principle is dangerous"

byjuvc
10-08-2006, 12:29 PM
what we do is charge the breaker spring and operate the release to close the breaker with about 30' of rope on it.
But in our case it is a push button and so we cant use a rope.

byjuvc
10-08-2006, 12:30 PM
What voltage is the feeder? They operate the breaker FROM the breaker?

There is NO way i would close a breaker, no matter the voltage , and especially after a fault, FROM the breaker.

Why can't you operate them remotely?

No way.

The voltage is 11 KV . Remote operation is not implemented yet on those panels

wormy
10-09-2006, 11:18 AM
Lots of distribution breakers have the controls on the breaker only. Have closed hundreds in standing beside of the breaker. If the breaker goes I don't think having your head turned is going to help. What we used to do is put the breaker in automatic control and then bring up a red closed flag. Breaker will not close instantly but will time and then close giving you a chance to move away from breaker before it closes. Hope this helps I used to work in substations

HighPotter
10-09-2006, 02:31 PM
Lots of distribution breakers have the controls on the breaker only. Have closed hundreds in standing beside of the breaker. If the breaker goes I don't think having your head turned is going to help. What we used to do is put the breaker in automatic control and then bring up a red closed flag. Breaker will not close instantly but will time and then close giving you a chance to move away from breaker before it closes. Hope this helps I used to work in substations


Wow.....and here I thought "I" worked on an old system.

I've been witness to a few CB's going ballistic, and it wasn't pretty. I would have hated to have to be close.

HP

wormy
10-09-2006, 04:29 PM
What voltage is the feeder? They operate the breaker FROM the breaker?

There is NO way i would close a breaker, no matter the voltage , and especially after a fault, FROM the breaker.

Why can't you operate them remotely?

No way.
Wow.....and here I thought "I" worked on an old system.

I've been witness to a few CB's going ballistic, and it wasn't pretty. I would have hated to have to be close.

These are not old breakers. They are breakers with the control cabinet on the side of the breaker. Voltage does not matter a breaker is a breaker. Transmission breakers are in a control house in most cases and distribution controls are on breaker. It is obvious highpotter you do not know much about substations from your post. It is called knowing what you are doing. With some knowledge you won't be near as scared.

I also doubt you have ever seen a breaker go ballistic. I worked in stations everyday for 25 years and never saw one go ballistic. I have seen some pretty good damage from where a snake, squirrel, or large bird go into the leads and got burned up. Stick to line work and stay out of stations if you don't know what you are doing

HighPotter
10-09-2006, 08:34 PM
What voltage is the feeder? They operate the breaker FROM the breaker?

There is NO way i would close a breaker, no matter the voltage , and especially after a fault, FROM the breaker.

Why can't you operate them remotely?

No way.
Wow.....and here I thought "I" worked on an old system.

I've been witness to a few CB's going ballistic, and it wasn't pretty. I would have hated to have to be close.

These are not old breakers. They are breakers with the control cabinet on the side of the breaker. Voltage does not matter a breaker is a breaker. Transmission breakers are in a control house in most cases and distribution controls are on breaker. It is obvious highpotter you do not know much about substations from your post. It is called knowing what you are doing. With some knowledge you won't be near as scared.

I also doubt you have ever seen a breaker go ballistic. I worked in stations everyday for 25 years and never saw one go ballistic. I have seen some pretty good damage from where a snake, squirrel, or large bird go into the leads and got burned up. Stick to line work and stay out of stations if you don't know what you are doing


Amazing.
We have 6 large substation in our system, with a total of 73 - ITE 7kv OCB's and 78- Alstom 69 kv SF6 CB's. I'm sure thats baby shit compared to your shop.

They are ALL operated from a control house. Yes, everyone of our subs has a control house or shed, where operation of the cb can be performed. And most of our subs are over 50 years old. Sure they have control handles or pushers that CAN trip or close the breaker, but we only use them when the position is taken out, and de energized.

I guess things aint done that way at you shop. Sorry bout that.

The fact that you havent seen a CB go up? well what can I say. I've seen 2. One was a 7kv 3000 amp OCB bus tie. CB was closed and held for 3 seconds, then the CT's exploded and oil let go. Showered the whole rack with oil. The other was a 69kv sf6 CB in a newer sub, built turn key buy a contractor. Manufacturer rep had replaced a bad bushing. Control center closes in, and we watched the just replaced bushing explode in a fireball, and pieces fly across the yard.

The fact that you question my experience is BS. That only tells me one thing.You must know everything. Whatever.

So I take it from your post, since voltage don't matter, you dont have a problem closing in on a 69, 115 or 235 kv sf6 breaker right at the breaker huh? Heck, 69kv at 900 amps, that aint shit, huh? Everything always works perfect, huh?

Just remember this Wormy, things aint always the same around the country, as it is where you work. Not only the type, style or way ya do things, but the loads as well.

Im done.

HP

wormy
10-10-2006, 04:28 AM
Amazing.
We have 6 large substation in our system, with a total of 73 - ITE 7kv OCB's and 78- Alstom 69 kv SF6 CB's. I'm sure thats baby shit compared to your shop.
Let me see, you have 6 substationsin your system. Your right this is baby shit compared to mine. We have alot of 765KV around here and a whole lot more substations


They are ALL operated from a control house. Yes, everyone of our subs has a control house or shed, where operation of the cb can be performed. And most of our subs are over 50 years old. Sure they have control handles or pushers that CAN trip or close the breaker, but we only use them when the position is taken out, and de energized.

You have breaker controls in sheds? Are your breakers in barns???I can see you working on 7kv but how much 69kv do you have in distribution.....


The fact that you havent seen a CB go up? well what can I say. I've seen 2. One was a 7kv 3000 amp OCB bus tie. CB was closed and held for 3 seconds, then the CT's exploded and oil let go. Showered the whole rack with oil. The other was a 69kv sf6 CB in a newer sub, built turn key buy a contractor. Manufacturer rep had replaced a bad bushing. Control center closes in, and we watched the just replaced bushing explode in a fireball, and pieces fly across the yard.

I guess you should learn how to do the work yourself


The fact that you question my experience is BS. That only tells me one thing.You must know everything. Whatever.
I question your experience because it is obvious you don't know much about substations


So I take it from your post, since voltage don't matter, you dont have a problem closing in on a 69, 115 or 235 kv sf6 breaker right at the breaker huh? Heck, 69kv at 900 amps, that aint shit, huh? Everything always works perfect, huh?
I repeat our controls for these voltage breakers are in a control house. Ever bonded onto 345kv or sticked 138kv?


Just remember this Wormy, things aint always the same around the country, as it is where you work. Not only the type, style or way ya do things, but the loads as well.
With the lack of explosions I think I will stick to our way

byjuvc
10-10-2006, 07:39 AM
What voltage is the feeder? They operate the breaker FROM the breaker?

There is NO way i would close a breaker, no matter the voltage , and especially after a fault, FROM the breaker.

Why can't you operate them remotely?

No way.
Wow.....and here I thought "I" worked on an old system.

I've been witness to a few CB's going ballistic, and it wasn't pretty. I would have hated to have to be close.

These are not old breakers. They are breakers with the control cabinet on the side of the breaker. Voltage does not matter a breaker is a breaker. Transmission breakers are in a control house in most cases and distribution controls are on breaker. It is obvious highpotter you do not know much about substations from your post. It is called knowing what you are doing. With some knowledge you won't be near as scared.

I also doubt you have ever seen a breaker go ballistic. I worked in stations everyday for 25 years and never saw one go ballistic. I have seen some pretty good damage from where a snake, squirrel, or large bird go into the leads and got burned up. Stick to line work and stay out of stations if you don't know what you are doing

Yes in our case we have controls of the breaker on the breaker itself . They are rated 11 Kv with a Imax of 630 Amps. Again this is the case at the switching stations . But the 33/11 KV Grid stations from where the 11 KV feeders to these switching stations begin are fully automated . We are not using oil anywhere in the panels or Breakers. It is sf6 everywhere.

Regards,

Byju

byjuvc
10-10-2006, 07:43 AM
Lots of distribution breakers have the controls on the breaker only. Have closed hundreds in standing beside of the breaker. If the breaker goes I don't think having your head turned is going to help. What we used to do is put the breaker in automatic control and then bring up a red closed flag. Breaker will not close instantly but will time and then close giving you a chance to move away from breaker before it closes. Hope this helps I used to work in substations

But unfortunately it seems we dont have such a facility ..

Byju

wormy
10-11-2006, 07:46 AM
First I would like to apologize to Trampbag for acting like an ass and second about the original question I was just saying if you have auto/manual controls this is an option for giving you a chance to move away from the breaker :)

HIVOLTS
10-21-2006, 10:19 AM
I Wouldn't Loose Alot Of Sleep Over Closing In A Breaker With The Control Handle Mounted In The Breaker Cabinet. Educate Yourself A Little Bit. I Haven't Seen An Sf6 Distribution Feeder Breaker, Most Of Them Built Now A Days Are Vacuum. If It Is A Gas Breaker There Will Be A Low Gas Alarm And Lock Out Relay To Prevent Closing, There Will Also, Most Likely, Be A Low Gas Trip That Will Trip The Breaker Before Gas Levels Are Too Low To Safely Operate The Breaker. With These Fail Safes Inplace There Are A Couple Of Things You Should Do, Always Clear Your Targets, If It Trips Back Out It'll Help You Identify The Problem. Make Sure The Recloser Is On Lock-out. This Restores Instantaneous Tripping. Open The "a" Switch And Try It.
A Vacuum Breaker Does Not Have The Fail Safes A Gas Breaker Would, Yet. I Heard One Manufacturer Has Built A Vacuum Monitor In The Bottle And Would Alarm With A Loss Of Vacuum. Still Closing In A Vacuum Breaker With Out A Good Vacuum On One Bottle
Could Be Hazardous, Especially If It Were To Trip Back Out. No Vacuum, No Arc Suppresion. I Do Keep My Head Below The High Voltage Compartment Panel When Operating A Vacuum Breaker From It's Control Handle. I Have Seen What A Bad Bottle Can Do, And The Panel Covers Will Come Off Violently, I Don't Care How Many Bolts Are In Them. Newer Breakers Do Have Blow-out Panels Or Ports On The Sides Of The Breakers To Direct The Blast Away From The Operator Standing In Front Of The Breaker. Comforting, Huh?