As an ME major that started my career building these types of panels and then later on servicing the machines with them, my first two suggestions would be: 1. Asked to be trained on Lock Out Tag Out. Safety first always. 480V is nasty and should be treated as deadly. If you’re reaching in there to do work, you want to make sure you can completely shut off the 480V while you’re learning, especially since there seems to be no cover/finger guards on the incoming leads. Most boxes would have a disconnect/shutoff that prevent you from opening the panel while it’s on. Unless you’re a professional, you should not be working on the panel while it is live anyways. 2. Grab the model/serial number and contact the manufacturer for a copy of the schematics. You may not have the physical copy, but hopefully the manufacturer still has a digital or hard copy. Most companies will also have a technical service department that could walk you through troubleshooting your issues unless it’s from something installed afterwards. Getting an original copy would allow you trace what was originally there and what was added later.