Hot restrike MH and generator

[AusLee]

Hello,

A football stadium is supplied by a 1MVA tansformer and we have a 1.1MVA Caterpillar generatort for backup. I have two questions:

1. My idea is that when there is an important game with TV retransmission, switch off the transformer and run the generator: this way, as long as there is fuel, there will be no risk of power failure during the game; and at the same time it will be a good exercise for the generator because when there are no games, this gen will be running on a small fraction of its power.

2. In case you don't agree with me in item 1, we are thinking of replacing some projectors in the lighting towers from normal type to "hot restrike" type, so that in case of power failure, the generator will start and within one minute, these projectors will be giving their 100% output and provide a minimum safety level of illumination until the rest of the projectors comes to their 100%, then the game continues.

The question is that someone is saying "hot restrike" projectors does not provide this service. Their trick is that they are active all the time, so anytime you switch ON the circuit, the lamp goes at 100%. But this "active all the time" means that there has to be energy available all the time, so, if the normal supply fails and we switch to generator, then this is one delay that does not make the projectors "online all the time" anymore, and so: when the gen gets connected all the projectors will start in the same manner; probably the hot restrike will be a little fatster than the others but not quite much, and the unperceivable difference will look more like "their is a problem with the other projectors" rather than a solution in the system (for the specators). What do you think?

 

[davidbeach]

Why not add a 1.2MW rotary UPS to allow the system to ride though the generator start time?

 

[AusLee]

There is not enough money for that

But tell me is that isuue with hot restrike real?

 

[mouli11]

I feel your plan no 1 is an ideal solution. But I do not understand the reason for switching off the Transformer. You can keep your Transformer also on and through an AMF panel you can feed power generator supply and in case the fuel is exhausted the power can be switched back instantly to Main supply through Transformer.
In my opinion the HOT restrike lamps do take considerable time to ignite and give full illumination.

 

[dpc]

The "Hot-restrike" lamps with restrike more quickly than a standard lamp, but it is not instantaneous and the light output will not be close to 100% when they re-strike. For safety, you should probably have battery-powered emergency egress lighting.

There is a flaw in your logic regarding Item #1. The engine-generator could certainly fail, so there is a risk of power failure regardless of what source you use. If you feel the generator is more reliable than your utility source, then your approach might make sense. You might also want to consider the noise issues associated with the generator.

 

[ruggedscot]

Simple solution if you want to avoid loss of power is to have a dual string and alternate your lighting between Generator and utility.....

Thuis if you lose one you only lose 50% and you can switch over to the availiable source if required.

Yes it comes down to cost. If your genny is more reliable than the mains then by all manner of means run it during the game but generally utility tends to be pretty reliable unless of course the utility company supports the other team ;-)

Id go for running on generator for the duration of the game that way you would be isolated from the grid. But splitting the load across would be a good way to get a resolution.

Rugged

 

[alehman]

This is a battery back that maintains the arc in the lamp in the event of loss of power. It's a possible solution, but might be very costly for the quantity required.

http://www.bodine.com/products/specs/arckeeper.html