I have a few questions about Power Distros that I've been wondering about for a while now. This isn't for any specific application, just my own curiosity and personal knowledge gain. Also, I understand that for most of this, there are a thousand legal and safe ways to do it, but I'm specifically wondering what the most common ways of doing things are, whether or not they are the most logical. I have a thorough understanding of the concepts behind 3-phase and 208V power and such, but I don't know how it's actually traditionally applied in a theatre setting.
So lets say you're building a medium-to-large sized touring package that will tour the US for a musical, with many moving lights and conventionals in the rig. For the conventionals, most of the time, you would reach for a few ETC Sensor+ 96 x 2.4kW Touring Racks with Socapex outputs. That seems to be fairly standard, at least from, what I've seen. My question is about what you do when you get into Non-Dimmed power for moving lights and other elements of the production, such as motor power. Assuming you had a rig of entirely 120V moving lights, you could theoretically populate your Sensor racks with enough Relay modules and just run everything through the dimmer racks. With a large rental package, is it fairly common to change out dimmer modules as needed for your production, or do you generally just take full racks from the rental house without any shuffling of modules? This question also applies to scroller power and other remotely controlled straight power devices, as well as to console power and other constant powered devices which aren't traditionally part of the actual lighting rig.
Now, lets assume that you have a number of fixtures that do require 208V power. How would you go about powering these? As far as I'm aware, there's no single manufacturer that everyone goes to, like ETC for dimmer racks. I also can't seem to find anything about "standard" sizes for power distros, the way that most dimmer racks come in standard sizes (96, 48, etc.). Are there standard sizes (other than multiples of three, of course), or are most distros custom built as needed for each production? Also, how would you go about mixing 208V power with 120V power? Would your ETC dimmers generally handle all non-dim 120V power (via modules) while the distro took care of 208V, or would you mix the two voltages in the same distro?
Now, assuming that you've procured the correct distro for the show, how do you spec power going to each fixture? Again, I'm speaking mostly to how things are normally done, not the minimum requirements to be in compliance with code. Can you use the same 6-circuit socapex cables that you use with 120V power, or something similar to them? Or do you generally use individual cables headed to each position? Also, I've often seen L6-20 connectors used on 208V lines, presumably to prevent accidentally plugging into the wrong voltage. Is this fairly standard, or is there another connector that's often seen?
And finally, once you get to the theatre, how do you go about tying everything in to a company switch? My assumption is that you'd usually go from the company switch into a distro, then from that into your dimmer racks, but I could easily be wrong. Also, are there other parts of a lighting rig that would receive direct 3 phase power from the company switch before being pushed through a dimmer rack or distro? I'd assume all power for the show would come from these two pieces, but I could be wrong.
Sorry for the long post. Thanks in advance!