It seems like there is a constant battle between mechanical designers, electrical designers, maintenance technicians and engineers over just what a properly fabricated control panel should look like. If it were up to mechanical, the panel would be the size of a breadbox and well hidden so that it wouldn’t destroy the clean lines of the machine. If it were up to maintenance you would be able to walk inside, turn on the light, sit down and fire up the laptop while sipping a beverage from the backplane-mounted vending machine. Engineers and electrical designers fall somewhere in between because as we know, they are the most firmly grounded in reality.
Plant specifications usually dictate what kind of layout an electrical enclosure will have. It is common to use divided wireway to separate AC and DC wiring, finger safe terminal blocks, distribution blocks for high voltage distribution and appropriately sized and colored wiring. For some reason the controller is usually somewhere on the left side of the backplane though either on top or at the bottom while most of the higher voltage distribution ends up on the right. This may be because flange mounted disconnect cutouts are usually on the right and single door enclosure hinges are usually on the left.
I have seen plant specifications where AC and DC wiring must be kept in separate wiring ducts, no dividers allowed. These same specs dictated redundant controllers, redundant power supplies and generally made for a much larger enclosure than usual. I have also seen panels with no wireway at all, wiring was simply tie-wrapped together. I’m sure this made the mechanical designers happy, but didn’t go over well with anyone else.
Regardless of your personal preferences and discipline, it is in everyone’s best interest to have a clean looking enclosure, properly labeled and with enough room for the inevitable work that will take place during troubleshooting and machine modifications. If your plant or company doesn’t have a wiring specification I would be happy to provide a good generic one free of charge. It doesn’t mention the cup-holder you may want, but you can add that yourself!