Load Calc, Redundancy & Permits
The single-line diagram is the production.
A power install is a load calculation, a phase-balance check, and a permit filing more than it is a stack of cable. Here's the work.
Load calculation. Two weeks before the event we collect equipment lists from every department — audio (PA, monitor world, FOH), lighting (moving heads, conventionals, dimmer racks), LED (panel count and processor draw), video (projectors, switchers), kinetic (winch motor banks), broadcast (encoder racks, UPS rigs), catering (warming racks, refrigeration), talent trailers (HVAC, lighting). Each piece has a published draw at full load. We sum the totals with 25% headroom and a phase-balance check across L1, L2, L3.
Service vs. generator decision. If the venue has spare service that covers the load calc, we tie into venue switchgear with a master disconnect at FOH. If venue service is short or unavailable (outdoor sites, brand pop-ups in parking lots, film locations), we spec generator capacity. Generator sizing is load calc plus 25% headroom, plus another 15% for surge tolerance during motor starts. Multi-unit configurations get paralleling switchgear.
Redundancy and life-safety. Critical paths get dual-feed redundancy. Egress lighting and audio for emergency announcement run on a separate phase from production, with an automatic transfer switch falling back to a backup source. Broadcast feeds run on conditioned UPS-backed lines so a brief generator transition doesn't kill the stream. For shows with two generators, paralleling switchgear syncs them so neither feeds 100% of load — either one carries the whole show if the other fails. Life-safety redundancy is non-negotiable on shows with audience capacity over 500.
Permits and inspection. Temporary power installations in LA County require permits from the local AHJ — LADBS, Long Beach, or county jurisdiction depending on venue. Generators with diesel storage need fuel permits. Outdoor events on public property need film permits with a power addendum. We file the paperwork, coordinate the inspection, and provide a licensed C-10 electrician on every install. Inspector-ready single-line diagrams ship with the truck.
Truck call and install. Generators arrive on day one of load-in, get spotted, leveled, and grounded. Camlock feeder runs from generator yard to the distro positions. Distro panels get patched in, every circuit labeled, master disconnects placed. Phase-balance check runs at first power-up, before any department is energized. We re-check phase balance after every major department comes online.
Fuel and 24-hour monitoring. Generators on multi-day events get a fuel tender on site and refueling scheduled around show breaks. Every generator has a tech on rotating shifts monitoring run hours, fuel level, temperature, and load. Faults page the on-call electrician within 30 seconds of the alert. Strike happens after the last department powers down and the master disconnect is locked out.