Will placing caps in series double their voltage rating?

[TechShui]

And placing them in parallel doubles their capacitance?

[mariushm]

Re: Will placing caps in series double their voltage rating?

Yes, provided they're the same voltage and capacity rating. When in series it's often recommended to connect resistors in parallel to balance the voltage on the capacitors and to drain them when the circuit is disconnected.

See this: http://www.aikenamps.com/AddingComponents.htm

[tom66]

Re: Will placing caps in series double their voltage rating?

Remember though two caps in series have half the effective capacitance.

[TechShui]

Re: Will placing caps in series double their voltage rating?

Thanks for the tips guys, I'll try this out

[PeteS in CA]

Re: Will placing caps in series double their voltage rating?

And putting two equal caps in series doubles their effective impedance.

[Ratjaws]

Re: Will placing caps in series double their voltage rating?

If I recall my CET schooling correctly I don't think connecting capacitors in series will increase their voltage rating. Correct me if I'm wrong but that rating is the maximum voltage before damage to the device becomes probable. While their effective impedience becomes less and therefore the voltage drop across them is less, the absolute voltage rating does not change. Placing two 120 volt caps in a series circuit should allow you to safely place 240 volts across the whole but the actual maximum remains unchanged. So my sense of this question says no, placing caps in series will not change their voltage rating.
Ratjaws@aol.com 051712

[PeteS in CA]

Re: Will placing caps in series double their voltage rating?

Well, if you think of the input circuit of a non-PFC P/S set for 240VAC, after the bridge rectifier you have two 200V capacitors in series. If 240VAC is applied, there is ~335V across those two capacitors. So clearly series-connecting capacitors of equal value and equal maximum voltage increases themaximum voltage of the circuit. Further, I have worked with P/S companies and in P/S groups for nearly 30 years, so far. I know that the design maximum AC voltage for such an input circuit is 264VAC, a DC voltaage across the capacitors of ~370V, or nearly double the 200V rating of tthe capacitors (and don't forget that electrolytic capacitors have a capacitance tolerance of +/-20%).

[daftpunker]

Re: Will placing caps in series double their voltage rating?

If I recall my CET schooling correctly I don't think connecting capacitors in series will increase their voltage rating. Correct me if I'm wrong but that rating is the maximum voltage before damage to the device becomes probable. While their effective impedience becomes less and therefore the voltage drop across them is less, the absolute voltage rating does not change. Placing two 120 volt caps in a series circuit should allow you to safely place 240 volts across the whole but the actual maximum remains unchanged. So my sense of this question says no, placing caps in series will not change their voltage rating.
Ratjaws@aol.com 051712

You are right. The voltage ratings of capacitor can`t be changed simply by putting them in series. What you accomplish by doing this is to divide the voltage potential among these capacitors. Since the parts might degrade at different rates, they might experience a different voltage level. In the worst case one part fails early and depending on the type of capacitor used the failure mode might be a short which forces the entire voltage drop across the non-failed capacitor.
the voltage rating is based on the life tests conducted by capacitor manufacturers that allows them to estimate the minimum life of capacitors under maximum operating conditions.