Hey all. I was reading a recent thread and it was mentioned that issues could occur in a system if all channels are brought up a once. I do this all the time to check lamps and have never had a problem. I always assumed that in a permanantly installed system this wouldnt be something to worry about. I ran a show at a festival where we had 300 amps of portable dimmers on a 200 amp feeder but we only had about 175 amps worth of lights, (I know not ideal, but it was what the rental rep set up, dont yell at me). I didnt ever bring up every light there to any level at once just becasue we were kinda flying on the seat of our pants load wise but again it probably would have been ok. So are most systems out there not capable of running with every light up, or is this not a common problem?
are there problems with bringing up every channel in a system at once?
- Thread starterAman121
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If you were to do it in my venue I would throw you out of the booth, not because it would overload anything but because it would incur a power peak on our electricity bill that could mean several thousand dollars more in monthly expenses that could have been avoided, and better spent on something else. There's no good reason to bounce the entire rig to full, and far better ways to test the integrity of the electrical system.
Never thought of that. How big is your rig? And what if you brought up everything sequentially to full but not all at once?
DuckJordan
Touring IATSE Member
Then you wouldn't have the demand charge.
DuckJordan
Touring IATSE Member
If I flash your rig to full you're going to have to pay thousands of dollars more on your bill? please, do explain...
Our electrical utility charges based on usage and peak demand. If we go above certain thresholds then the billing structure changes and costs us anywhere from $600 to $2000 per month in additional demand charges, depending on the peak. If we were an office building we would be better off paying a high demand charge because it is offset by a lower usage charge. Since we are theatre with an uneven usage pattern, we get penalized by the demand charge but see negligible benefit from the reduced usage charge.
Google "peak demand charge" for much more detail than I can provide.
I don't buy that at all.
If the lighting system is properly designed and installed and you have the power available, there should be no problem with going from 0 to full with everything. I've done it before as a cue with no problems at all. And the higher electric bill is something I've never heard of before. The only issue I see is that it's probably not the best thing in the world for lamp life.
Am I wrong? I'd love to hear from some of the electrical pros here on CB.
DuckJordan
Touring IATSE Member
You are completely wrong, My facility is the same way, the one on the other side of town is the same way. As a business you are charged a usage fee, and if your usage isn't "Steady" they will tack a demand charge. So anytime your building lets say is dormant for a week, then you turn your rig on 600+ amps, now you have a demand charge because you need 600 amps now. Residential never sees something that big because they'll likely never pull more than 100 amps total for an entire house. Not to mention the seldom times you pull from 0 to 100 amps at once.
CrazyTechie
Well-Known Member
At my dad's work their power bill is calculated based off of their highest power draw for the month, since they are a business rather than residential. They have several large compressors for moving cement powder between the rail-cars and the silos for storage and then into the semi trucks for loading. My understanding of the way it works is if, for example, one morning they started up all of the compressors at the same time ,incurring a large power peak, they would be charged for the entire month based on that large power peak.
So for example lets say their normal peak during a cycle is 100kW and lets say that costs $0.10 and hour. (I'm just making up the figures here for simplicity sake). If on that power draw they drew say 1000kW at $1 an hour, for that billing cycle they would be charged the $1 per every 100kW drawn.
That's my understanding of how it works and I hope I used the terms correctly.
So for example lets say their normal peak during a cycle is 100kW and lets say that costs $0.10 and hour. (I'm just making up the figures here for simplicity sake). If on that power draw they drew say 1000kW at $1 an hour, for that billing cycle they would be charged the $1 per every 100kW drawn.
That's my understanding of how it works and I hope I used the terms correctly.
In my day job I'm a P.Eng (electrical) with a university background in power distribution and control systems. Does that make me 'pro' enough?
There is no way to determine where you live and what billing structure is in place for your facility, so maybe there is no problem in you doing what you do. If your lighting rig is small enough it may not matter anyway, even if your electricity supplier does have demand billing, or maybe it is large enough that you are into demand billing with the HVAC load alone.
If the show requires the entire rig at full then that's the cost of doing business. If there is no need for it, then why would you choose to incur the cost when it provides no benefit?
While not intending to dismiss anyone's expertise, this doctor wants a second opinion.
My understanding of demand charges is that the utility computes the average usage for 15 minute intervals. You'll get billed for the highest 15 minute interval for that month. So if you have 2 large power hungry machines, it's to your benefit to use them alternately if possible.
What we're talking about here is a VERY quick, sudden spike of in-rush current when everything is brought up at once. While I can see making a point that this stresses the lamp filaments (and dimmers), I can't see the electric bill going through the roof and breakers tripping if the system is properly installed.
If I'm wrong, please feel free to explain why.
My understanding of demand charges is that the utility computes the average usage for 15 minute intervals. You'll get billed for the highest 15 minute interval for that month. So if you have 2 large power hungry machines, it's to your benefit to use them alternately if possible.
What we're talking about here is a VERY quick, sudden spike of in-rush current when everything is brought up at once. While I can see making a point that this stresses the lamp filaments (and dimmers), I can't see the electric bill going through the roof and breakers tripping if the system is properly installed.
If I'm wrong, please feel free to explain why.
It's hard to say, first off because one of you is in Canada and the other is who knows where.
I can tell you my college gets hit with peak demand charge all the time, the question is how peak is the demand change. Part of the reason the school invested in some renewable energy technologies like steam co-generation for our heating plant is because they installed oversized capacitors (used to keep power generation steady) which would reduce the 'height' of the peak demand spike when the college chillers kicked in.
The logic of charging is pretty sound from the utilities perspective, they are over-generating to cover these high spikes in power usage all day long. This is the same reason the power amps in most venues have a 60+ second power on sequence, partially because of the load on the rails but in SOME cases it's due to billing power as well.
I can tell you my college gets hit with peak demand charge all the time, the question is how peak is the demand change. Part of the reason the school invested in some renewable energy technologies like steam co-generation for our heating plant is because they installed oversized capacitors (used to keep power generation steady) which would reduce the 'height' of the peak demand spike when the college chillers kicked in.
The logic of charging is pretty sound from the utilities perspective, they are over-generating to cover these high spikes in power usage all day long. This is the same reason the power amps in most venues have a 60+ second power on sequence, partially because of the load on the rails but in SOME cases it's due to billing power as well.
hobbsies
Active Member
I feel like this thread has been sidetracked by electric billing procedures.
There are 2 things you should know about bringing every channel to full to do a lamp check. First, bringing a cold lamp to full puts a lot of strain on your lamps, and you will blow through your lamps a lot faster than what your lamps' advertised life. The second issue is part of this power strain argument. If you have enough power to support all of your fixtures on at full, I'd say that's pretty rare.
What I do, is I have a "warmup cue" where I bring all of the conventional fixtures to 15-20% over the course of a minute, and leave them on for several minutes. This lets your warm up your lamps without causing them to blow, and gives you the opportunity to do a broadway check (looking up at all the fixtures to see if any are out). If there are any out, you can quickly identify which ones are out. This is also a good method to use if you don't have an RFU of some sort. Some of the newer boards have a channel check function that lets you easily step through channels one by one, but only do a channel check after the warmup cue has finished.
JD
Well-Known Member
Peak demand surcharging is a pain, and something to be aware of. Now, if there are systems in the building that exceed what the dimmers system demands, then it becomes irrelevant. However, if the dimmer system is your largest draw, then activity can effect the rate structure. In the "old" days, there was often a paper chart recorder. These days it is just another thing tracked by the digital meter. Lets say you had a theater that was going to be vacant for a couple of months. The act of a sudden peak would make a large difference in your billing, even though the amount of KWh consumed was very low.
Let's not sidetrack it further with a discussion, previously argued vociferously, of Preheating Conventionals?.
So THATS what that method is called. I've always been a fan of that, and my stage managers have been as well.
I've never heard it called a broadway check. I've always just been taught its a lamp check. Preshow always involves everything at 10% and checking for blown lamps/ burnt out gel.
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