Breaker cost

Status
Not open for further replies.

mbrooke

Batteries Included
Location
United States
Occupation
Technician
Most are live tank now.

I've seen that around the world, but not so much in the US. We use dead tank 90% of the time for both existing and new installations (see pic). But since you bring it up, why is live tank preferred over dead tank? What advantages do live tank breakers have?
 

Tony S

Senior Member
I've seen that around the world, but not so much in the US. We use dead tank 90% of the time for both existing and new installations (see pic). But since you bring it up, why is live tank preferred over dead tank? What advantages do live tank breakers have?

What medium are they using for the arc quenching?

SF6 is unpopular due to environmental issues, so air blast became the norm. That said there were complaints about noise with the early units.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
What medium are they using for the arc quenching?

SF6 is unpopular due to environmental issues, so air blast became the norm. That said there were complaints about noise with the early units.

SF6, still common in the US if I am correct. My understanding is that vacuum only works at lower voltages.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
OEM, design, ratings, features, locations, etc... but figure somewhere in the $250-$350k range if you are just curious. And they still typically use SF6, just less gas than older styles.

How much does interrupting capability add to the breaker, ie 20ka, 40ka 63ka? Also what do you mean by OEM (custom)?
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
I represent that insinuation :D

live tanks are cheaper, about the only reason I can see
although they require external CT's which offset some of the savings

How much cheaper? Ive seen the external CTs on those and they take up space. Not sure of the advantage, but if external CTs are less prone to saturation I guess it could be an advantage (not sure if thats true however)
 

Fulthrotl

~Autocorrect is My Worst Enema.~
SF6, still common in the US if I am correct. My understanding is that vacuum only works at lower voltages.

ten years ago, SF6 was what all the new stuff being installed around where i was at was using.... but the
environmental issues were rearing their ugly head at that time, to the extent that LADWP had bought some
enormous amount of SF6, to cover their needs for 50 or 60 years of maintenance on all their SF6 gear....

i don't know if there is any agent that could be substituted for SF6, and i'm thinking opening or closing a
SF6 switch that wasn't fully charged, would not be a good experience.
 

zog

Senior Member
Location
Charlotte, NC
How much does interrupting capability add to the breaker, ie 20ka, 40ka 63ka? Also what do you mean by OEM (custom)?

I'm not sure what the adders are for that type breaker but in the MV world doubling the int rating can be up to a 50% adder. By OEM I mean manufacturer.
 

kingpb

Senior Member
Location
SE USA as far as you can go
Occupation
Engineer, Registered
I have it on good authority that you are somewhere around $95K for the 115KV and $270K for the 345kV. And as an added bonus even though you didn't ask, $150K for 230KV.

These are for 63kA.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
I have it on good authority that you are somewhere around $95K for the 115KV and $270K for the 345kV. And as an added bonus even though you didn't ask, $150K for 230KV.

These are for 63kA.

Thanks, this is the info I needed :) Am I correct that the price of these has gone down over the years?
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
ten years ago, SF6 was what all the new stuff being installed around where i was at was using.... but the
environmental issues were rearing their ugly head at that time, to the extent that LADWP had bought some
enormous amount of SF6, to cover their needs for 50 or 60 years of maintenance on all their SF6 gear....

i don't know if there is any agent that could be substituted for SF6, and i'm thinking opening or closing a
SF6 switch that wasn't fully charged, would not be a good experience.


Don't these breakers have a lockout that prevents opening on a leak? I hope at least an alarm.

As for the environmental aspect, its all lies imo. Much like the R12. Its said that the military was the biggest contributor from their air force, not people dumping refrigerators. But to cover themselves consumer took the hit.
 
Status
Not open for further replies.
Top