Question for the HVAC guys who use potential relays, I'm building a rotary 3 phase converter and will be using a potential relay to disengage my start capacitors to my idler motor. I'll be running it on 220v and will have a start capacitor bank somewhere between 1800 and 3000 uF (30 hp converter) that will have pretty high inrush current. From the other 30 hp converters I've seen, as high as 350 amps of inrush current will be needed to get the motor up to speed.

Are there any good articles written out there on how to select the right potential relay for larger industrial applications? I've been learning the ins and outs of electrical circuitry but am relatively new to potential relays, goal is to not blow up my kind of of expensive start capacitor bank in trial and error

The magic of the Google contains your answer.
ahcrnews

But I'm cheap and don't wanna pay a subscription

Upon thinking on it some more, I would be using this potential relay to open/close a contactor that would be handling the brunt of the load. Maybe my question shouldn't be how big of a potential relay to get but how to wire it into a contactor and operate it with a much lower current from the start capacitors.

That site should not be behind a paywall.
It's a series of articles of which some contain wiring diagrams. If you go to the bottom of the article it will provide links to previous articles in the series.

I'm confident your answers can be found there but if you need more help there is plenty of pros who can assist.