An Uninterruptable Power Supply (UPS) Room is where all the power distribution for a Central Apparatus Room (CAR) is stored. The purpose of the UPS room is to distribute power to all the broadcast kit and air-handling units in CAR, as well as to provide power back up when there is an issue with the main supply. The back up power is generally only a few minutes, this gives enough time to shut down systems correctly so no data is lost. In extreme cases such as data or broadcast centers the battery back up will still only last a few minutes but this gives enough time for the diesel generators to start up so even if a power cut lasted several hours CAR would still be able to work as normal.
The main power supply to the UPS room in Ravensboure is 1600A 3 phase 415V. This mains current gets distributed to 3 places:
- Air-handling units
- Battery chargers
The air-handling units at Ravensbourne are not on an Uninterruptable Power Supply due to the fact that they run off a 3 phase current and the battery back up system has not got the capacity for this much power.
I have created a quick example of how the power is distributed around the UPS room.
The switchgear is where the battery back up can take over if the mains goes out. This system in its basic form is a relay switch on each output socket, if mains power stops it switches nearly instantaneously to battery power. For Ravensbourne this gives between 10 and 15 minutes of power, long enough to shut down all the broadcast kit correctly. From the switchgear the mains is distributed to all the sockets in CAR. Some switchgear systems also have surge protection built into them, smoothing out the current to the broadcast kit and giving it a longer life.