Power Path

A general overview of the power path.

The three phase and single phase power starts in the plant room. There is a large black switch for the single phase to the proj box and a bunch of trip switches for the three phase to the projectors (a trip switch for each of the phases). The power then 'enters' the proj box through the switch located on the wall, this brings the contacts together for both the single phase and three phase in the contactor box (located under the floor).

When a stop button is pressed (there are six located in the proj box next to electric machinery and near the exits – ask a projectionist to show you exactly where) it breaks both the single phase and three phase contacts, effectively cutting power to the equipment that uses these sources.

Once 'entering' the proj box the power then goes to the circuit breakers located next to the platter. The three phase doesn't actually go there but can be cut by tripping the three phase contactors switch located on the circuit breaker box. There is also a bunch of single phase trip switches for the projectors (even though the projectors use three phase a lot of the switching mechanisms inside use single phase hence tripping this switch will cut power to the projector), platter, amp racks, sound processors etc... Look on the board for more details.

WARNING: It is important to trip the single phase supply before working on a projector.

With regards to the projectors, once the power has gone 'through' the circuit breaker it then goes through the fuses. Ask a projectionist to show you these. If a red LED comes on it means the fuse is blown. The fuses are labelled and once the correct fuse is known it can be replaced.

With regards to the sound rack; after the circuit breaker the power goes to the necessary amps and processors.

With regards to the control box that controls the smaller control panels next to each projector (for shutters and lights); after the circuit breaker the power goes to the large control box (there is also a bunch of fuses inside the large control box) and then to the control panels.

Other details

You can turn the lights on in the proj box without turning on the main power switch. Hence it is on a separate circuit. Also the masking can be controlled at the bottom of the auditorium without using our buttons so once again must be on a separate circuit. The trip switches for these are located in the ceiling.

The lights in L3 can be turned on without power to the proj box. Hence - you guessed it - must be on a separate circuit. The trip switches for all the lights in L3 (spots and fluorescents) are located in the plant room. Ask a qualified projectionist to show you these.

There are other bits and bobs that haven't been included and if something stops working and you are unable to solve it using the power path or divine intervention then don't panic and call someone on the emergency contact list. Located next to the power switch in the proj box.