[Al Skierkiewicz]

Adam,
The first time I encountered this type of block was in the power distro of our analog transmitter. This transmitter was built in Missasauga, outside of Toronto. All tranmsmitter module power is 50 volts so the distro is very complex. There are 8 2kW (conservative) modules in each of two cabinets for each of two transmitters. Total power is 800 Amps for a fully black picture.
In our digital transmitter we have dual redundant power distro in large cabinets on one wall of the transmitter facility. Three phase power comes in through these blocks, then distributes to the rest of the cabinet where everything electrical is mounted on DIN rails. To protect the final amplifier, the mains breakers are motor driven trip so that mains voltage will be removed within two cycles of the power line sine wave upon fault. The mains voltage then routes to time delay relays which first insert huge resistors to limit "inrush current" and then following a sufficient time delay, bypass the resistors for full power. There is obviously a variety of telemetry devices installed in the cabinet as well. Everything is installed on DIN rails including small relays like those used for the orange light. Inside the transmitter cabinets, the same rail mounted terminal strips are used for all three phase and low voltage wiring. (low being anything less than 300 volts.) This includes all blower power, DC power supplies, control wiring and telemetery. All high voltage wiring requires special handling and special hardware to prevent arcing and corona discharge. It also requires some very special safety controls so that high voltage cannot be applied with the covers open or circuitry bypassed. High voltage in this transmitter is 35,000 volts at 2 amps.