Cap banks vs static banks

[shaun]

Why hang static capacitor banks when you could just hang regular cap banks with a sec control box? What's the difference between the two? Ones always in and one when it need to be.

[Fiberglass Cowboy]

Engineering usually determines what kind of capacitor banks we hang at my work, usually driven by the necessity for achieving better POWER FACTOR, which can be driven/determined by the state public service commision. Power factor has to do with achieveing "true working" power, not so much "inductive" or "reactive" power. Too much either way outside of "true power" can cause generators at power plant to "lag" or "lead". Not good for your transmission circuits. It's like not getting the best "bang for your buck."

So we still hang permanent (fixed) banks, time/temp. banks and VAR (controlled) banks (according to the kvar size of the capacitor - and what is needed for that location).

Our permanent banks now-a-days have oil switches on them, so they are always online but still much safer to work on than the "old fashioned" fixed/permanent banks.

COOL.

P.S. Lot of fancy words but I still have much to learn about them.

[freshjive]

we hung one yesterday, and ours have vaccum switches on them...Side note:

What i found really weird about these banks is that they have a temperature factor that you have to remember..If it is under 60 degrees, they will not trip open or trip closed...I don't know why, but they didn't work the other day when we punched in the command in the box and we couldn't figure out why right away..Someone then remembered that temp affects the operation of these banks when its chilly out (and it was about 50 deg. out), which i found strange..I mean 60 degrees isn't that cold and these things endure much hotter and colder weather than 60 degrees...You have to go up there and manually hit the little levers on the vaccum switches to make it either trip shut or trip open.. I'm just surprised that the temperature that it stops working at wasn't a lot lower...................

[Fiberglass Cowboy]

That is known as a TIME/TEMP bank, my young padwon. One of the common 3 styles of capacitor banks.

Say hi to the guys at NSTAR ELECTRIC, as I heard you were being bought out by NATIONAL GRID. Like I said before, I know a few apprentices that work for NSTAR, 1 in Boston and 1 in Worcester. And a retired foreman (now trainer of apprentices for the Nstar training crews) from the company and a few other retirees,all out at the Cape. All good guys. Later Wicked Pissah Kid.

[shaun]

Engineering usually determines what kind of capacitor banks we hang at my work, usually driven by the necessity for achieving better POWER FACTOR, which can be driven/determined by the state public service commision. Power factor has to do with achieveing "true working" power, not so much "inductive" or "reactive" power. Too much either way outside of "true power" can cause generators at power plant to "lag" or "lead". Not good for your transmission circuits. It's like not getting the best "bang for your buck."

So we still hang permanent (fixed) banks, time/temp. banks and VAR (controlled) banks (according to the kvar size of the capacitor - and what is needed for that location).

Our permanent banks now-a-days have oil switches on them, so they are always online but still much safer to work on than the "old fashioned" fixed/permanent banks.

COOL.

P.S. Lot of fancy words but I still have much to learn about them.

Thanks FC. I appreciate it! I was askin because we were sent out to a broken pole with a static bank on it but replaced it with a sec controlled cap bank. The cans on the bank say electrical operation only. Can't operate them remotely cus there isn't any. I used a stick and pulled the rings down then pulled the fuse doors on the cutout.

[Pootnaigle]

Ya jus never know when yer gonna getta big surprise tryin to open a static bank. Oil switches are definately the safest reguardless of how they are activated. nowadays they use fusebreaK cutouts on the static banks and they do werk but ittza pain inna butt to refuse em all, Back inna day we used Them dern Flashguard jobs and after a few years the sunlight deteriorated the plastic,N that coupled with the fact that the blades didnt always line up make fera bad sperience tryin to close em.Never hadda prollem with Oil switches behind cutouts.

[tramp67]

Sometimes the engineers will throw a static cap bank on the line to help correct the power factor, which helps raise the voltage, on older lines until they can budget a line rebuild/upgrade to catch up with increased load. Switched banks offer much better control of the system, and are used more often on heavily loaded circuits. The type of control used on switched banks has a lot to do with the type of customers or load on the circuit. Temperature controls are used frequently where there is a lot of A/C load, time is often used with lots of industrial load, ie large motor loads. Some controls measure the secondary voltage on the control power transformer, and switch the caps on when the voltage drops below a preset value. Cap banks are some interesting creatures on the electrical system, and are often underutilized, in my opinion.

[australiantroubleman]

We use some field capacitor banks ,usually on the end of long feeders or in industrial areas to help with voltage regulation and loading.
They are always switched off at night via time switched vacuum circuit breakers to avoid excess voltage rise and unneeded var flows when loads are down.
Have regular problems with them after reclose on feeders sometimes they blow the cutouts on reclose , have tried lots of different speed cutout elements but the problem persists,something to do with the inrush reactors not doing their job correctly.

Like you say they are interesting devices but can bite you on the ass if your not careful how you switch them.