I have a Phase Technologies brand phase inverter that electronically converts my 230Volt single phase shop power to 230v 3 phase. It works great and is way quieter than my old rotary converter. The problem is I have to replace the 4 filter caps every year or 2. They are marked 60uF +-6% 480VAC/B and appear to be oil filled, marked: "a combustible fluid". The brand is CSC with a part number of 325P606H48P46A4NPT. Other than Phase-Tech, does anyone have an idea where to source these caps or a replacement? The company wants almost $300 for a set of 4.

I spoke to tech support and they said that these caps filter input noise. A way to extend their life would be to add some type of external filter. I'm not sure where to get a filter that would work for 230volt ac at 175 - 200 amps.

Any input is appreciated.

 

It does not seem reasonable that a 60 MFD 480VAC capacitor is used as "a noise filter" in a single phase to three phase converter device. The less expensive three phase converters tend to use capacitors to provide phase shifts to deliver a three phase output. The alternative scheme is to rectify the mains power and have a three phase inverter producing the output phases.
In any case, an AC rated 480 working volt capacitor would probably also be used for electric motor applications. So I would suggest one of the industrial electric product sellers. That could be GRAYBAR . For "keywords" I suggest using "electric motor capacitor".

 

It does not seem reasonable that a 60 MFD 480VAC capacitor is used as "a noise filter" in a single phase to three phase converter device. The less expensive three phase converters tend to use capacitors to provide phase shifts to deliver a three phase output. The alternative scheme is to rectify the mains power and have a three phase inverter producing the output phases.
In any case, an AC rated 480 working volt capacitor would probably also be used for electric motor applications. So I would suggest one of the industrial electric product sellers. That could be GRAYBAR . For "keywords" I suggest using "electric motor capacitor".

The modern three phase inverters are all digital with a high frequency PWM modulated carrier. So yes, there does need to be a output filter to cleanup the PWM carrier from the utility frequency fundamental output. You're right, the standard 60 MFD 480VAC capacitors are designed for utility frequency phase shift duty, not for use as a high frequency carrier filter.


Pulse width modulation creates switching frequency currents and harmonics which superimpose on the fundamental AC frequency. The output filter capacitors must filter the entire spectrum from fundamental to harmonic frequencies. Metallized polypropylene has low loses across a wide bandwidth of frequencies making it the premier choice for filtering inverter outputs.

https://www.ecicaps.com/tech-tools/technical-papers/ac-film-capacitors-for-inverter-output-filters/

https://www.cde.com/resources/catalogs/PFCH.pdf

 

WE were never informed as to just what the scheme was for producing the three phase power. My guess was that older scheme.

 

WE were never informed as to just what the scheme was for producing the three phase power. My guess was that older scheme.

Yes we were.

have a Phase Technologies brand phase inverter that electronically converts my 230Volt single phase shop power to 230v 3 phase

 

Your capacitor is marked CSC. That was Commonwealth Sprague Capacitor. That product line was sold to Nueva Generacion Manufacturas S.A. many years ago. It is probably obsolete from them also. It is a metallized poly-propylene film cap in an oil-filled can that was in the CSC Motor Run family. As someone linked already, CDE (Cornell Dubilier) might have something equivalent. Also Ronken Industries.