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Author Topic: Generator sizing for d-cinema auditorium Justin Hamaker Film God Posts: 2253 From: Lakeport, CA USA Registered: Jan 2004 posted 10-21-2019 04:27 PM                        A new reality of life in Northern California is the potential for "Public Safety Power Shutoffs" from PG&E as a way to help prevent fires from electrical equipment during high wind events. Due to the risk of business interruptions from these outages, we are looking at the possibility of installing generators that will be able to power our two largest auditoriums. I'm curious if anyone has worked up the size generator is needed to run and auditorium using an NEC NC2000C with a GDC non-imb server, and the related peripherals. I realize every location is different, but I'm trying to get an idea on what I need.  |  IP: Logged Frank Cox Film God Posts: 2234 From: Melville Saskatchewan Canada Registered: Apr 2011 posted 10-21-2019 05:54 PM                        A good clamp meter would probably tell you what the peak power consumption is at the main panel box. Or you could estimate it by watching your electric meter. Remember that there's more power needed than just what's running the projector and sound system. There's the popcorn machine, lights, the exhaust fan in the mens room.... Not to mention the air conditioners, heaters...  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 10-21-2019 07:49 PM                     You need to consult a qualified electrician on this to get it right. It is not something you'll want to go back and change out again because of the expenditure. PLus, you will legally be obligated to run all emergency and egress lighting in the building if it is occupied and a qualified electrician will be able to tell you exactly what in your buildings has to be powered. You may also want to power any cold storage. Mark  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 10-21-2019 08:30 PM                        There is more to this than just the generator. Generators take some time to start and stabilize when power is cut. Generally, you would want the equipment to be on a UPS that would be capable of powering everything for a few minutes in order to allow the transfer to generator power to take place. I have no idea what that would cost, but it would require a fairly mondo UPS. Also, most UPSes designed for computer equipment aren't really good at powering other things (most don't have a proper sine-wave output, for example). The transfer switch is an important piece, and a possible point of failure. Also, generators come in diesel and natural-gas varieties. Diesel has the benefit that it is not dependent upon the public gas supply (which might not survive an earthquake, for example), while natural gas has the benefit of not needing on-site fuel storage. For a cinema, natural-gas is the obvious choice, assuming that the building has gas available. Either type requires regular maintenance. My only personal experience with this stuff is in a data-center environment, so I can't be more helpful, unfortunately. The point about exit-signs and fire safety equipment above is a good one, too. My guess is that keeping a cinema fully operational through a power outage probably won't be cost effective. A small generator for emergency lighting is probably a good idea, though, even if your local code doesn't specifically require it.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 10-21-2019 10:34 PM                     Some Tesla Power Walls charged via solar or similar would probably work for 5 minutes until the genny is on line. It can take 5 or more minutes some times for one to start up and warm up to a point you can then bring it on line. The generator in this picture is 1.5 megawatts and located on Farnsworth Peak at the DTV transmitter site. There is a gigantic UPS behind it that is on auto-transfer if the main power feed fails. The UPS can run 8 DTV transmitters for about ten minutes, or just long enough to warm up the generator and switch over to it. You don't need one anywhere near this large, but you still need an adequate sized unit to run those screens and some ancillary stuff. And possibly a fuel storage tank as well for a long term run. You may also find that for a little more expenditure that you can get a large enough unit to run all the screens. Mark  |  IP: Logged Marcel Birgelen Film God Posts: 3357 From: Maastricht, Limburg, Netherlands Registered: Feb 2012 posted 10-22-2019 03:33 AM                     I've done datacenter related work for many years. It is something you really need to work out with a bunch of trained experts. For datacenters it's pretty simple: everything except the cooling needs to be on UPS and everything needs to be on the generator. But consider a hospital, stuff becomes a lot more complicated already, making the correct sizing of emergency power systems much harder. If you don't want to be able to light up your entire building but just sections of it during a power outage, then it's going to be quite complicated as you really need to decide what systems you're going to need and what not. You essentially would need to adapt your internal wiring for this. It's hard to know the complexity of that, without having a complete overview. Then there are the systems you really need to have on a no-break/UPS system and those you can live without for a few minutes. Since you probably can't afford to redo your whole wiring, you would need to work with smaller UPS units around your building. Stuff you probably want to put on a UPS besides your servers and projectors are also the lamps of your projectors as a show will be seriously hurt when the lamp of your projector goes out. Then there is the sound. Do you accept people sitting in complete silence for a minute or two? Or do you want to put the sound system on UPS too? Depending on the wattage, those are already quite some beefy UPS systems you need for that alone. Also keep in mind that putting in stacks of batteries around your building creates extra fire hazards. Talk with somebody of your local fire brigade about it, they often don't like those distributed UPS systems or they require something like a central "emergency off' switch for them, as those autonomous systems pose a serious risk for electrical shocks for them. Then there are also the "backbone systems" like switches, TMS and other server systems, like PoS systems. The same may be true for your box office and concession PoS systems. Then what do you want to do with your lightning? You probably have an emergency lightning system that takes over once the power drops out, but putting your lightning on the generator is an absolute requirement. You can ask yourself if putting it on UPS is a requirement too, because I've noticed that lights going out will generally cause a little panic. If you have switched your lightning to LED entirely, putting it on UPS will be far cheaper, but still, it adds up. Don't forget systems like airco and/or heating. Especially air-conditioners are power hungry beasts, but you probably don't want to run without them. The same goes for heating, even if you're using e.g. gas for heating, don't forget that heating units themselves, ventilation and pumping systems will all require quite some electrical power. You don't need to put them on a UPS, but you need to account for it when sizing your generator. Sizing the generator, in the end is pretty easy. Simply run everything you need and you can reliably "shed" when the power drops at maximum performance and measure what you need. Add at least 30% for comfort and that's what the generator needs to give. Another thing to consider, when installing a generator, is the amount of fuel it can store. Although most systems can be refueled while they're running, in my experience, expensive contracts that guarantee a refill within x hours are often worthless. If the shit hits the fan, you'll see that those companies are totally over-stressed and there's always an excuse of not getting to you in time, often those excuses are legitimate, like a flooded road, etc. So, having a fuel reserve of at least 48 hours is pretty crucial in my opinion. Last but not least: procedures and testing. You need to have the proper procedures in place and you need to test your setup regularly. You shouldn't be afraid to eventually do this while you're open. You should be confident that your emergency power works the way it should work, even if you're not around yourself pulling the levers. The best way to do it, is to regularly run on those systems. The first few times you'll be switching over to emergency power, you'll find those many little things you haven't thought about. After you've done it a few times, stuff should start to go smooth. Also, switching back from generator power to the net is something that needs to be thought about. Do you switch back automatically or manually? How do you know your feed is sufficiently stable to accept your load? Lots of things to think about. Off course, if you're talking about planned outages, you can plan ahead and do a more orderly transition, but make sure your emergency power system doesn't come back to bite you. You're adding lots of new components, components that can be operated wrongly and components that can break. I've seen those systems fail and facilities go dark, while their external feeds never went off-line... Maybe you think that I'm dramatizing it a bit, but I've been there.  |  IP: Logged Jack Ondracek Film God Posts: 2348 From: Port Orchard, WA, USA Registered: Oct 2002 posted 10-22-2019 09:57 AM                        A lot of this is good information, but much is related to specific functions. In my parallel field (broadcast engineering), I maintain generators at transmitter and studio locations. In both cases, there isn't much that's unusual or specific to the industry. Critical equipment, such as office computers and rack-room gear are backed up by UPSs until the generator spins up and takes over. Any generator I have over 40kW has a block heater that keeps it moderately warm. Those units are up, ready to go and on load within 10 seconds of the time the power goes down. In some smaller stations that suffer infrequent, short-term outages, Generac home-type generators work quite well. They take a bit longer to run up, because they don't start on a hair trigger. Even then, they are on-line within 20 seconds. I have had a generator at my drive-in for over 20 years. It has actually been on-line with customers only 6 times or so. Each time however, I had nearly 1,200 people on the property. That's a lot of passes, missed cheeseburgers and unfulfilled expectations... and few places are as inky dark at night as a drive-in in the middle of nowhere. In my opinion, even having saved only those evenings, the generator has been well worth the investment. One winter, we were down for 3 days, due to numerous power poles being dropped by ice. In that case, the generator kept our house and walk-in coolers at temperature, and we lost nothing. When ACE installed my digital gear, they put in two Tripp-Lite UPSs on each screen; one 240 volt unit for each projector (Barco 23 and 32b's) and a 120 volt unit for the server and network equipment. My lamps are not on UPS and go down until the generator takes over, but restart quickly. All of my other computers (POS, audio processing, etc) are on UPSs. The exit lights are LED-based and have their own batteries. In my case, the only catch was to up-size the generator enough that it could manage the starting current required to spin up the 3-phase compressors I have on my walk-in cooler and freezer. Everything else was able to be easily measured by a clamp-on ammeter. As for running a generator in California... good luck with that one. A friend of mine down there is the operations manager for a small group of radio stations. He says the paperwork & permitting required to run a generator in California is typical of the bureaucratic absurdity that prevails there.  |  IP: Logged Bruce Cloutier Expert Film Handler Posts: 161 From: Gibsonia, PA, USA Registered: Aug 2016 posted 10-22-2019 11:30 AM                        This is an interesting topic. I bet all of these outages are creating new business for companies supplying UPS and generator systems. That means costs will go up and it will be hard to find people who can do the work in a timely fashion. Hopefully many are already using reasonable UPS equipment. Around here we see occasional <5sec power dropouts. I envision some power company employee moving the clip leads on the big transformer someplace to adjust for load variations during the day. If you aren't on a UPS things reset and it disrupts everything. The DirecTV DVRs here go through a reboot that takes some 20 minutes. Hint: Check your UPS batteries periodically. This is the reason that I added a ride-through power supply to the JNIOR 412DMX. It's there for us to evaluate but basically the power input on the JNIOR stores enough energy to keep the unit running for 15 or 20 seconds when external power is lost. So it "rides through" the power glitch and doesn't reset. It also lets us log the power event. The jury is out as to whether or not this is worth adding to the remainder of the JNIOR line. We figure most need to be on a UPS anyway. And, it frustrates those of you who like to reset the JNIOR by yanking the power. Jack, your involvement in a parallel field might answer something that we have been wondering about here. It must be a common thing. We have JNIORs in a lot of cinemas. I am not sure about drive-ins. But we are surprised to find them popping up in broadcast company locations. Mostly security related though. They monitor remote transmitter buildings and issue emails and/or texts. You can run the same sensors that you would use in a security system to the JNIOR's inputs including motion detectors and all of that. I guess they also monitor environment and I am not sure what else. We just couldn't figure out how they found their way there. Perhaps you're to blame?  |  IP: Logged Jack Ondracek Film God Posts: 2348 From: Port Orchard, WA, USA Registered: Oct 2002 posted 10-22-2019 05:51 PM                        Not sure if it was me, Bruce.... maybe, but... I would like to get some more info though. What you describe is very common here... mostly low voltage analog metering (<12Vdc), logic status and dry relay contacts for control, event-based notification, calendar-based relay activation and some level of if/and/or/then scripting. Most of the control and monitoring equipment for US radio stations is made either by Burk or Broadcast Tools, with 2 or 3 other companies taking up minor shares of the market.  |  IP: Logged Justin Hamaker Film God Posts: 2253 From: Lakeport, CA USA Registered: Jan 2004 posted 10-22-2019 06:00 PM                        Let me clarify a bit on what we are looking in to. First and foremost, we are looking for a generator circuit which will power our refrigerator and freezer to protect product. This generator would also power lights to the common areas of the building - restrooms, hallways, etc. This would also power the office and at least one of the POS terminals so we could close out business if power was lost. Secondly, since we are on a well, we are looking at a generator which will run our pump and water treatment building. This would ensure the fire suppression system remained functional, as well as protect this critical equipment. Third, we are looking at a generator which would provide sufficient power to run our two main auditoriums so we could at least maintain limited business during a prolonged power outage. We are very realistic about what we would need to be able to keep operating. The purpose of my question was to get a sense of how much power an auditorium would need to keep running. All of this would be weighed against the cost of a generator which was capable of running the entire business. I also want to add that this is not a DIY project. We are working on getting quotes from electricians who specialize in generator installs. Part of the reason for my question is so I have enough information when talking to the electricians. The information about the UPSs is something I hadn't considered before, but it makes perfect sense.  |  IP: Logged Marcel Birgelen Film God Posts: 3357 From: Maastricht, Limburg, Netherlands Registered: Feb 2012 posted 10-23-2019 02:15 AM                     Instead of buying a generator, there is also the possibility of renting one. The last time I did such a calculation, the rental prices for a heavier model wasn't all that much higher, so it made sense to put the whole building on a generator. This also saved us the headache of adapting the internal power grid. It's not really easy to do a general estimate of the power consumption of a single auditorium, as there are so many variables that come into play. Below, I made an estimation of an average sized room, seating about 150 to 200 people, but I may be overestimating or even forgetting some important factors. Server: 0.5kW Projector: 0.5kW Lamp: 5kW (based on 4kW lamp + overhead) Automation and other doodads: 0.5kW Audio system: 6kW (based on 10 amps @500W + overhead) Other audio components: 0.5kW Booth Airconditioning and ventilation: 4kW Room lightning: 2kW Room cooling: 15kW Total: 34kW Let's assume a Power factor of 0.7, then this would require about 48 kVA without any overhead margin. It's obvious that this is based on a lot of assumptions. Like the lamp in the projector, the amount of cooling needed, which is very dependent on the climate and the sizing of the audio system, which is also very dependent on the size of the auditorium. The same goes for stuff like auditorium lightning. Are you already using LED everywhere? How bright is it in there? Do you use any kind of power hungry special lightning? Also, the Power factor is something pretty specific to your situation, although I guess that 0.7 is a worst-case scenario in the case of a modern cinema auditorium. Those estimations are based on peak usage of all systems concurrently. In practice this doesn't happen very often, but you still have to design for it. You know, that hot summer night, where everybody flocked to your cool theater to watch the latest uber-loud blockbuster in 3D...  |  IP: Logged Lyle Romer Phenomenal Film Handler Posts: 1400 From: Davie, FL, USA Registered: May 2002 posted 10-23-2019 05:49 AM                     Also consider if your heat (even if you rarely use it) is electric. When I did my home standby generator, the local code required that the generator be sized for the maximum power of all circuits which would be connected to it. In order to power the A/C, the calculation needed to use the power consumption of the electric heating elements, which I have never actually used living in South Florida, but which use more power than the A/C. You definitely want to research the local electrical codes to see if things like this (that don't really pass the common sense test) apply.  |  IP: Logged

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