VFD is blowing my RCD

[Doddy]

There's a lot of ambiguity with the OP's description.

Firstly, how have you connected an Arduino PWM output to the VFD? I'm guessing this is a run-of-the-mill HuanYang VFD - no-where in the manual describes setting this up for a PWM input (ref. configuration parameters PD002 and PD070). You mention some external drivers and electronics, is this providing the PWM to analogue conversion?, details please.

Let's get back to basics. Isolate the Arduino. Just have two switches - connected between FOR and DCM (this is your On/Off), and between VR and VI (this is your 0/100% speed control), set PD002 to 1 (default = 0) and PD070 to 0 (default). Then test the behaviour using just these. If your problem goes away then it's nothing to do with "surge of power".

I've had the same vfd and spindle setup for almost a year and not had this issue.

So what's changed?

and previously it was the surge of it starting

I've read the description a couple of times. Maybe too early in the morning for me but I can't see where you discuss starting problems.

I hooked it up the same way it had been connected.

Let's have a look at the wiring diagram for this.

Also, please confirm that you've earthed the VFD.

I don't always agree with A_Camera but just this once - yeah - please post some relevant photos of the wiring to the VFD, and confirm the PD002 and PD070 settings.