About using AC contactor for DC switching Voltage?

[akhilr]

I want to use the AC contactor(i.e. who's contacts are made for switching AC voltage) for switching DC voltage(in my case 300VDC).What is the De-rating factor(Also provide the formula for the De-rating factor) I have to apply if I want to use AC contactor for switching DC voltage.Can I use AC contactor which has switching capacity of 415Vac for switching 300VDC voltage.Also i want the De-rating factor for the Current to be considered.

 

[lee26loo]

Yes, you can use this parts. The same contacts even can take higher rate of DC current compair to the AC current rate. For example: some product marks the contact can take either 3 amperes AC or 10 amperes DC depending on how and what the contact material is made. For a general guide line,use the same AC rate applies to DC is safe enough.