Capacitor Bank

Your question carries the answer as well. Because it is Star connected.

Hey, mine is too. Small world!

The system is 11 kv phase to phase but the voltage for the capacitor is phase to neutral.

sir, if it is 3phase capacitor, is it ok

As long as you parallel one terminal of each capacitor & connect to neutral, it is ok. Connect the second terminals to separate phases. You will be using 3 capacitors.

Thts fine sir,

but if check the voltage between two phases in one end of capacitor (line voltage) will be 11kv, ie, it should have the insulation level of line volatage, it shall be rated for line voltage?

You will have 3 capacitors & each capacitor will be connected between a phase & the neutral. Each capacitor will be connected to one phase.

God, I hope you're not doing this for real.

Why not? Please elaborate. How would you connect it?

if it is 3nos. single phase cap. I understood sir, I checked the old drawing, there it was 3nos. 1phase capacitors, in the last revision it is found, as 1no. 3phase, so i hope it might be an error, only my doubt is if we are using 3pahse and 3nos. single phase voltage rating to be varied or not. ie

if check the voltage between two phases in one end of capacitor (line voltage) will be 11kv, it should have the insulation level of line voltage, it shall be rated for line voltage? im worried about the insulation level between terminals L1,L2 and L3 only.

thanks

You have a valid point there. If the capacitors are delta connected, then these caps. will see full phase to phase voltage. I think there could be some error/mistake. After revising the caps. for delta feed, they forgot to revise the voltage rating. Please put your query to your designer/consultant to revise the voltage rating of caps.

Exactly in the way you describe, sir, but I am not calling your replies into question.

Rather, I am expressing my considerable dismay that the OP has evidently been entrusted with the design/connection of power distribution equipment yet without the requisite knowledge.

For a person working in this capacity, the norm is to expect that such a person would already be fluent in the basic, intermediate and advanced principles and would already know why those capacitors have the ratings they do and correctly explain that to others. It is one thing for a student to be asking such questions; quite another for a practising engineer to not know the answers.

If the OP is a student, well and good, because the OP's questions are a student's questions. But, if the OP is working in a professional capacity on live equipment, he or she is a danger to himself and others.

It appears, what you have is a 3 phase harmonic filter. I am sorry, I have erroneously taken it to be PF correction caps. Therefore, what I have said in my posts above, please be ignored. Could you post a sketch?

Thanks for your response, my question was regarding the insulation level only operation voltage it's ok, now i got the reply from vendor, that they will give conformance letter regarding the insulation voltage. as he said im a beginner in switchgear feild, thank you once again,

Series reactors are installed on HV cap banks for several reasons: Reducing the inrush current and associated high-frequency voltage transients when a cap bank is switched on, reducing the high-frequency voltage transients during back-to-back cap switching (turning on a second cap bank when one is already on the system), and voltage limiting when the cap bank's breaker trips under fault conditions. All of these stress the insulation of the electrical system, particularly the circuit breaker's insulation.

The reason that the reactor's insulation only needs to be rated for phase to ground is that it generally does not see phase to phase voltage across it. It is a passive, conductive component in the bus, so the voltage on it is always phase to ground.

thanks a lot, wish u a happy new year