We have old textile machines (Riter ring machine) that have an inverter - very large size and it contains 12 capacitors (400 volt, 2200 uF.)

The problem is we have 20 machines and almost every month an inverter explodes and all the capacitors melt.

As a solution I am planning to use higher voltage (450 volt) capacitors.

Is that solution?

The capacitor link is here or at this link or are there any alternatives?

  • 2
    \$\begingroup\$ IMO, I'd look for why your inverters are exploding rather than changing your capa's with onces that can only take 50V more. 400V or 450V is basically the same \$\endgroup\$
    – Swedgin
    Sep 4 '19 at 14:53
  • 1
    \$\begingroup\$ which company/country made these machines? I'd expect 10x better lifespan if you INSTALL FANS and keep the capacitors 10 degree C cooler. \$\endgroup\$ Sep 4 '19 at 14:54
  • 3
    \$\begingroup\$ The ESR of the capacitors is critical as well. Higher voltage rating alone is not enough to make a substitution if they can't handle the ripple current. In fact you may want lower ESR/higher ripple current rating instead of higher voltage to solve the problem. Without knowing root cause you're basically flying blind. \$\endgroup\$
    – John D
    Sep 4 '19 at 15:15
  • \$\begingroup\$ keep the circuit VERY COOL. Direct some AirConditioning into the electronics. \$\endgroup\$ Sep 4 '19 at 16:35

Nothing will happen, it is fine to use higher voltage capacitors than the previous capacitors. The voltage rating indicates the max voltage. If the capacitor has a higher max rated voltage, then that's fine, because the product will have an operating voltage lower than 400V.

Check the ESR in the datasheets and make sure its lower than the current capacitors.


The first answer was by an author with the name "Voltage Spike".

And exactly that could be the problem here, besides a temperature issue that was mentioned already.

Power surges from thunderstorm strokes or from big electric motors or transformers switched off or from other electric equipment, or from an unreliable neutral connection (f.e. in case of a 3 phase supply) somewhere in the net could destroy these inverters.

If power surges turn out to be the reason, protection against power surges must be installed or improved and the source of those surges must be eliminated, if possible.


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