Dear all,

I am looking for a DC SSR capable of handling a maximum DC current of 300A under a maximum switching voltage aroud 250V. maximum conduction duration is 10 seconds, once each ~15minutes.
The best I found till today is a 100A SSR.
Anyone with any previous experience with such item? anyone has any previous experience connecting multiple SSRs in parallel to increase current switching capability?

Thanks in advance for any help.
Wissam.

What is the nature of the load, capacitive inductive or resistive ?
Do you have access to any auxiliary voltage of about 12V referenced to the load return connection ?
It may be more practical to create a DC switch function using an optically coupled gate driver, and some paralleled Mosfets, assuming that the load is DC and not bi-directional.
What is the switch maximum ON resistance that you need in the application?

This really isn't that difficult unless you need ultra-fast switching. As a previous commenter stated, you'll need a bias supply of 10 to 18VDC, which could be made from the 250 VDC, but if you need isolation, you can buy an off-the-shelf DC-DC Converter to convert 250VDC to 12VDC at 1-2 watts. Using MOSFETs, you can parallel without a lot of trouble. It would be harder using IGBTs.
That's all I can give you without knowing more about your requirements. Good luck.