[SML] house light control systems recommendations needed

[e-mail frank.wood95]

What you are describing in not what I call an emergency, rather a
serious inconvenience. A real emergency is when you have to evacuate
the auditorium, fast. Depending on the efficiency of your
communications, it is quite possible for the LX operator to say "Some
silly b****r has turned the house lights on", and react by turning
them off again. Hence the override.

The rest of the system is a standard requirement in the UK. In the
event of a power failure, emergency lighting must be provided from a
completely independent source, and this must include all the exit
boxes and routes. Nowadays, this is often done with rechargeable
batteries in each fitting. This is an administrative nightmare to
check and maintain. The other way is to use a central battery running
dedicated 50V fittings. This is less trouble to maintain, but not
zero-trouble. The batteries are usually open Ni-Cd or Ni-Fe cells,
which require periodical checks on the electrolyte. They also need,
from time to time, to be put through a full discharge-charge cycle.

The trouble with both is that they usually monitor only one phase, so
if either of the other two fails, the automatic system may not
operate.

Back-up generators are notoriously unreliable. Their starter batteries
als need maintenance. I was once in a big transmitter station when
they tested the big diesel back-ups. It took them six minutes to come
on line! This is not tolerable in a potentially life-threatening
situation.

Until quite recently, some theatres used gas lighting, at least for
the exit routes. I can certainly remember this at Covent Garden on the
interminable exit stairs from the uppermost balcony, on the fifth
level of a big opera house.

On 4 December 2014 at 00:19, Riter, Andrew <andrew.riter at ubc.ca> wrote:
>> One missing point from all the posts seems to be what happens in an
>> emergency
>
> In our situation, the emergency system is activated outside of the dimming/control system.
>
> Select house and stage lights are on a relay.  1 side of the relay is the dimmer supply, and the other side is the emergency system (land line and then genny).
>
> If the Relay control circuit loses power, the relays throw to the emergency power supply, and lit up the room.
> If the fire alarm is activated, the system triggers the relay and the system lights up.
>
> So there is no need for human interaction to turn on the lights in an emergency.
>
> If there is a need to evacuate without triggering the emergency system (bomb), then the console operator would turn on house and work lights.
>
> Andrew M. Riter
> Assistant Technical Director / Head Lighting Technician
>
> 604-822-2372
> Andrew.riter at ubc.ca
>



-- 
Frank Wood