I need an electrical engineer

I own a small motorhome which has a generator and 30 amp shore power. The power comes in to a smart switch from the shore and the generator and from there to an EMS (Electrical Management System). The EMS is not working and I cannot purchase a replacement. I need the EMS converted to a simple Circuit Breaker. I have already purchased the breaker but the conversion is too complex for me. I did replace the EMS 5 years ago but now that EMS is no longer manufactured.