Plastic Capacitors versus Oil Filled Metal Case Capacitors

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HKFC Power Electronic Capacitors vs other Metal Enclosure Oil Filled Power Capacitors:

HKFC Power Electronic Capacitors
Metal Enclosure Oil impregnated Power Capacitors

Durable strong plastic enclosure is relatively safer than metal can protection

Metal Enclosure – Unsafe, especially for High Voltage applications
Higher Insulation Resistance between Capacitor Terminals and Capacitor Body. This is crucial for High
Voltage and High Ambient Temperature application
– Low Insulation Resistance between Capacitor Terminals and Capacitor Body
– Capacitor Insulation Resistance will decrease as ambient temperature increase, that makes the situation even worse
High Insulation Voltage between Capacitor Two Terminals, and between the Capacitor Terminals and Capacitor Body – much Safer Low Insulation Voltage
Very low Leakage Current between Capacitor Terminals and Plastic Enclosure High Leakage Current between Capacitor Terminals and Metal Enclosure. This can shorten a lot of problems.
Smaller ESR and ESL Larger ESR and ESL due to the complicated internal connections
HKFC Capacitor can be operated up to 105C, depends on customer’s application requirement

Low operating Temperature, most of the metal can capacitors in the market with +65C rating.

Smaller Thermal Resistance Rth, even at 85C and 105C Higher Thermal Resistance Rth
Doesn’t have or small clearance and creepage distance Larger clearance and creepage requirement
Plastic Capacitor Enclosure doesn’t need Grounding Metal Capacitor Enclosure needs to be Grounding.
Plastic Capacitor Enclosure doesn’t have rust and oxidation problem. Metal Enclosure will have oxidation and rust problems
Filled with Epoxy Resin – Dry Design Filled with Oil Impregnant
Doesn’t have the impregnant liquid leakage problem Impregnant leakage problems – especially oil spillage on-site. This is a disaster to the End User, Application manufacturer and Capacitor manufacturer.
Dry design capacitor can be a  environmental friendly approach. Impregnant Oil is not that environmentally friendly
All plastic parts, both Plastic Enclosure and Epoxy resin are UL94-V0 grade Cannot meet UL94-V0 grade
HKFC Capacitor can be installed in any orientation Have installation orientation restriction
HKFC Capacitor can withstand stronger external vibration when compared with Metal Case Oil impregnated capacitors
Cannot withstand vibration
More reliable, compact, lighter weight and more energy efficient Less reliable, compact and Volumetric efficient
Longer capacitor life Shorter capacitor life – Metal Enclosure has rust, oxidation or oil leakage problem