Have you tried testing the RCD on ramp and without the device connected

I couldn’t even get it to reset. I disconnected the load cables and it stills Tripped.

It’s been sent back to China for tests. Despite what you all might be thinking, this is a reputable brand.

If you cannot test it when disconnected i’d guess it’s beyond use.

Yep. Needs replacing. It has been suggested to bypass the RCD. I’m not ready to do this. I believe there’s a problem rather than nuisance tripping 

How old is the circuit and why has it now started operating under no load?

Two weeks old. Was tested and inspected and commissioned by the manufacturer 

At a guess, you have a NE fault or your device is at fault. Really hard to say without looking at the circuit 

At a guess, you have a NE fault or your device is at fault. Really hard to say without looking at the circuit