Contactor & Fuse Combinations

[thatmarkdude]

Hey,

I'm attempting to redesign a switch and the new design in supposed to encorporate contactors in series with fuses. However, one of the requirements is for no contact welding to occur. The rated surrent has been calculated as 2405A and the maximum fault current is 40kA.

So I understand that for a given fuse and a given current flow, by using the time current characteristic one can easily find out how long it takes for the fuse to blow. However, naturally I assume that if the current is too high for a long time period, the fuse might only blow after contact welding has occurred on the contactors.
Is there a method of finding out wheather or not contact welding will occur before a fuse blows in a circuit?

Cheers

 

[cuky2000]

See if infor in the link below can help

http://www.eaton.com/Electrical/Con...leased&Rendition=Primary&dDocName=TB02003001E

 

[gattie]

Suggest you Google & read up on IEC type 1 & type 2 Coordination with regard to welding of Contacts.
Good Luck

 

[ScottyUK]

The IEC 60947 series of standards to be more specific. Wasn't this discussed in your other thread?