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

You can adjust the speeds at the HMI

Its very hard to say without looking at it. If it fails under no load and the neutral is disconnected I’d go for the device. But if neutral is connected and it has loads attached i’d look at the load. I am not an expert RCDs have always been neutral issues in my previous experience 

If you do find the fault I interested

It’s a machine fault that is blowing RCDs. I replaced the RCD and it ran for 4 days and now will not reset load free. I believe there a earth leakage fault >200mA. I have not considered frequency as being a problem. Having spoken with the operator that had increased the speed.

The only time I seen this happen was a three phase RCD that was three pole with single phase loads on it. Got it replaced with a four pole RCD and was okay

These are 4 pole RCDs

3 phase. No neutral 

Neutral installed to the machine but not utilised 

Theres a good document out there that shows how type b rcds are good for picking up high frequency hamonics for mode four ev chargers. They can burn out type a rcds

Is that not ya problem? You may need a Delta RCD without neutral

Is that not ya problem? You may need a Delta RCD without neutral