Illimite has a series of contactors designed specifically for switching capacitors in power factor compensation applications.

The contactor shown at the right is suitable for up to 72kVAr at 480v. The contactor has a set of auxiliary contacts that close momentarily before and during the closing of the main contacts. Resistors (coils of wire above and below the unit) are inserted into the circuit for between 5 and 10 milliseconds to substantially reduce inrush current.

Contactor web 60kVar02

All contactors are UL, Canadian UL and CE approved.
We are able to supply units suitable for all size applications and welcome the opportunity to work with you to select the appropriate contactor for your application.

Here is an example of the amount of current that can be reduced using this approach:
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This shows switching 50kVAr without the auxiliary contacts and without chokes. The vertical scale of the oscillogram is 2000A per division showing over 8000A inrush peak to peak.

This second oscillogram again does not use the auxiliary contacts but chokes are in the circuit. The vertical scale is 200A per division showing approximately 1000A peak to peak inrush.

The last oscillogram is again at 200A per division on the vertical scale and this time both chokes and auxiliary contacts are in use. The peak to peak inrush has been reduced to under 400A.

The great reduction in current provides longer contact life & less stress on the capacitors. Contact Illimite Inc. for available contactor sizes, price and additional information.