Yes, good point. Pushing the system too hard is not efficient any way, and more boxes is more efficient power wise. Not space, weight and budget wise though
I'm going to use these subs: https://www.hoqs.eu/products/hoqs-eu-df-212-subwoofer equipped with LaVoce Wan 124.01
Generally I understand that over excursion is not as likely with paraflex subs in general since the cone stays quite controlled, but you need premium elements with strong motor force. It will also help that I will not run them very low, and I selected subs that trails off below 40Hz on purpose. I find it quite useless with really low sub frequencies for the kind of music we play. So I have been filtering it anyway when using subs that can reproduce below 30Hz. Just sounds muddy otherwise, unless you play music that is produced with it in mind and where instruments actually hit those notes. That will probably be a big power saving since every octave down demands 4x the power, and longer cycles have time to drain the caps, putting the demand back on the power supply.
I'm planning to run 3 phase. 32A @240 should probably be enough even if I decide to get some more amps and subs, but I always used 3 phase when I rented generators. And I have a nice 32A 400v power distro box in the rack with current and voltage readouts.
Also, as I mentioned I would like a backup generator at home anyway, and then it has to be 3 phase if I want to connect it up as a fallback.
Cannot view that link from here, but I see that it is line interactive, which means it doesn't constantly generate a sine wave and only activates when input power fails. At least it says it has sine wave output, so is better than your typical line interactive UPS, but I think it has to be an online double conversion UPS for it to be any use, apart from providing backup power if generator fails for a few minutes.
Perhaps I need to quote this part again:
But anyway, here's a double-conversion type: https://tripplite.eaton.com/smarton...-serial-bypass-switch-hardwire~SU6000RT4UHVHW
Been thinking more about the solution to run the amps from DC, and it makes a lot of sense as the inverter to handle large amounts of power probably is both the most expensive and inefficient part if using an online UPS.
But I fear my electronics knowledge is not good enough to start constructing even quite simple system when dealing with 400v AC and 240v DC :\
Selecting the right rectifier and capacitors to get a safe system that does what I want it to seem like it would require someone with expertise I lack
And it is the kind of work that would have to be at least verified by a qualified electrician, so will need to find a pro to involve if going that route.
But I fear my electronics knowledge is not good enough to start constructing even quite simple system when dealing with 400v AC and 240v DC :\
Selecting the right rectifier and capacitors to get a safe system that does what I want it to seem like it would require someone with expertise I lack
And it is the kind of work that would have to be at least verified by a qualified electrician, so will need to find a pro to involve if going that route.
If you are doing this commercially, or even semi-commercially do not make those sorts of modifications. It’s not a question of if something will eff up but when and how often.
That being said, switch mode power supplies actually run BETTER off the native 330-400V (exact voltage depending on PFC) than they do off the rectifier and AC. If the system were properly designed to run off the DC bus you will have far less power supply sag and more peak and RMS output power.
I used to be able to strap old PC power supplies for 220 (full wave rectifier mode) and feed them 330 VDC. They worked flawlessly. But no one in their right mind will ever sign off on it, and the problem of the exact rail voltage that the SMPS wants to see remains. Without PFC it’s always about 340V, but with PFC it varies. If some gear wants 340V and others 390 you have a problem. Too much voltage out of the secondary side and you blow the amplifier portion so it needs what it needs. PFC circuits can and will malfunction if the input is not the expected sine wave so it would have to be bypassed. Those kind of equipment modifications will put you in deep doggie doo If it ever comes to light.
That being said, switch mode power supplies actually run BETTER off the native 330-400V (exact voltage depending on PFC) than they do off the rectifier and AC. If the system were properly designed to run off the DC bus you will have far less power supply sag and more peak and RMS output power.
I used to be able to strap old PC power supplies for 220 (full wave rectifier mode) and feed them 330 VDC. They worked flawlessly. But no one in their right mind will ever sign off on it, and the problem of the exact rail voltage that the SMPS wants to see remains. Without PFC it’s always about 340V, but with PFC it varies. If some gear wants 340V and others 390 you have a problem. Too much voltage out of the secondary side and you blow the amplifier portion so it needs what it needs. PFC circuits can and will malfunction if the input is not the expected sine wave so it would have to be bypassed. Those kind of equipment modifications will put you in deep doggie doo If it ever comes to light.
Yes, commercially it is not really viable having a unit with 220v DC outlets that you are supposed to put the right type of AC amplifier in
Probably the best commercial solution would be to build amp with extra capacitors. It seems like even quite beefy amps are still designed to run of mains power that allows for the extra peaks anyway. I would have thought there would be a market for amps that ensure that they draw a steady averaged amount of power. It is quite common to run systems of generator power, and nowadays on inverters and such that might not be able to supply sufficient peak power either. It would certainly increase cost and size of the amplifier, but would result in less cost and emissions due to having to use larger generators. To me it seems like the cost of extra capacitors and perhaps some controller would quickly pay for itself. But, yes, it is also possible the rest of the world is smarter than me and they don't exists because there is no demand or it will not work out as I think in practice
In my case it is not a commercial enterprise, and just for private use. So while that legally means a lot less liability if something goes wrong, I won't go near circuits with those voltages myself unless under professional guidance.
Probably the best commercial solution would be to build amp with extra capacitors. It seems like even quite beefy amps are still designed to run of mains power that allows for the extra peaks anyway. I would have thought there would be a market for amps that ensure that they draw a steady averaged amount of power. It is quite common to run systems of generator power, and nowadays on inverters and such that might not be able to supply sufficient peak power either. It would certainly increase cost and size of the amplifier, but would result in less cost and emissions due to having to use larger generators. To me it seems like the cost of extra capacitors and perhaps some controller would quickly pay for itself. But, yes, it is also possible the rest of the world is smarter than me and they don't exists because there is no demand or it will not work out as I think in practice
In my case it is not a commercial enterprise, and just for private use. So while that legally means a lot less liability if something goes wrong, I won't go near circuits with those voltages myself unless under professional guidance.
Decided to go ahead and get a portable power station. It is something I do want anyway since power interruptions has started to become a thing here lately. Ideally I would like something 3 phase so it can completely take over the whole house power on interruption, but I also like something that I can charge from solar rather than relying on diesel or petrol. And neither portable power stations nor inverter generators seems to exists in 3 phase. And it seems like the 3 phase online UPS units tend to be clumsy and not really made for dragging in to the forest.
Usually the portable power stations with decent output power is very costly though, and while still not cheap, there is a very good deal today on the Allpowers R4000 that can give 7000w peak and can charge and supply power at the same time, so basically work as an online UPS in a portable package.
https://iallpowers.eu/products/allpowers-r4000-portable-power-station-4000w-3600wh
I'm thinking that is really only for the subs I need to ensure that they have enough capacitance to average out the draw. For tops and other equipment that will not be an issue. So I can use a 3 phase generator plugged in to my distro, but put the power station or single phase UPS before the sub amp.
The R4000 might be a little weak to run the subs fully with 8000w RMS, but could on the other hand probably run the whole system quite loud for a few hours. At least I can try it out and see how far it can push the sub amp, and return it if it seems to weak to be any use.
Usually the portable power stations with decent output power is very costly though, and while still not cheap, there is a very good deal today on the Allpowers R4000 that can give 7000w peak and can charge and supply power at the same time, so basically work as an online UPS in a portable package.
https://iallpowers.eu/products/allpowers-r4000-portable-power-station-4000w-3600wh
I'm thinking that is really only for the subs I need to ensure that they have enough capacitance to average out the draw. For tops and other equipment that will not be an issue. So I can use a 3 phase generator plugged in to my distro, but put the power station or single phase UPS before the sub amp.
The R4000 might be a little weak to run the subs fully with 8000w RMS, but could on the other hand probably run the whole system quite loud for a few hours. At least I can try it out and see how far it can push the sub amp, and return it if it seems to weak to be any use.
When you get a UPS, there are few things to keep in mind.
You calculate your load in kw.
The load will have inrush that may last more than a few cycles.
The UPS power section must be able to deliver twice that calculated load.
You should also consider powering up the devices in sequence, may be use some breakers.
Number them 1, 2, 3 etc so when you restart, won't miss the sequence.
The battery backup time in minutes.
Consider fuel filling time, restarting delays etc.
Take twice this time in sizing the battery.
Some UPS have a feature that shuts off output if the load drops to less than 10%
Make sure you do not get one like that.
When you rent generators, there may be a minimum KVA rating offered by the supplier, say 25 KVA.
Get a quiet generator that comes in a sound proof enclosure.
Keep two extinguishers nearby.
Regards.
You calculate your load in kw.
The load will have inrush that may last more than a few cycles.
The UPS power section must be able to deliver twice that calculated load.
You should also consider powering up the devices in sequence, may be use some breakers.
Number them 1, 2, 3 etc so when you restart, won't miss the sequence.
The battery backup time in minutes.
Consider fuel filling time, restarting delays etc.
Take twice this time in sizing the battery.
Some UPS have a feature that shuts off output if the load drops to less than 10%
Make sure you do not get one like that.
When you rent generators, there may be a minimum KVA rating offered by the supplier, say 25 KVA.
Get a quiet generator that comes in a sound proof enclosure.
Keep two extinguishers nearby.
Regards.
Seems like I misunderstood how the unit works, and noticed that it does have a UPS mode with a switchover time of 15ms.
So it is working like a line interactive UPS rather than online, and I doubt there is a way to override that.
It does accept 2000W on solar input, so I guess in theory one could have a charger connected to generator that supplies 2000w, or have a DC generator, and make it work like an online UPS that way, but will give a few 100w less input power.
I wonder how it acts when you have both solar and AC inputs connected, because it can accept total of 4000w that way, and perhaps it cannot use UPS mode when combining inputs and that will force it to provide power through the inverter, which would be great. Have asked manufacturer to clarify, so we'll see what they say.
So it is working like a line interactive UPS rather than online, and I doubt there is a way to override that.
It does accept 2000W on solar input, so I guess in theory one could have a charger connected to generator that supplies 2000w, or have a DC generator, and make it work like an online UPS that way, but will give a few 100w less input power.
I wonder how it acts when you have both solar and AC inputs connected, because it can accept total of 4000w that way, and perhaps it cannot use UPS mode when combining inputs and that will force it to provide power through the inverter, which would be great. Have asked manufacturer to clarify, so we'll see what they say.
So I think the portable power station is a no go, but it is already shipped and has a 30 day money back guarantee so I guess I will test it out.
I'm now thinking the best approach would be to simply rectify the output of the generator and plug it into a solar inverter. A 20kW 3 phase inverter that can handle between 160v and 1100v input can be had for around €1500. Adding a decent sized bank of capacitors in parallel I hope it should be able to both ensure a nice sine wave with constant voltage and be able to add extra capacitance needed to get an nice averaged draw.
This also adds the advantage of being able to better run unbalanced loads, since those inverters often have balancing abilities allowing 50% of total output to be drawn on one phase.
I'm now thinking the best approach would be to simply rectify the output of the generator and plug it into a solar inverter. A 20kW 3 phase inverter that can handle between 160v and 1100v input can be had for around €1500. Adding a decent sized bank of capacitors in parallel I hope it should be able to both ensure a nice sine wave with constant voltage and be able to add extra capacitance needed to get an nice averaged draw.
This also adds the advantage of being able to better run unbalanced loads, since those inverters often have balancing abilities allowing 50% of total output to be drawn on one phase.
IS there any advantage to 3 phase inverter? 3rd harmonic ADDS in the neutral on a 3 phase system - it cancels in single phase. The advantage of 3 phase is on a motor or generator - producing uniform power over the complete cycle causing less mechanical load variation compared to a single phase motor. They just run smoother, and they are self starting (no need for run caps which like to die in the middle of the summer - how many times have you had to replace it on your A/C?). Your load will be as steady as it is going to be anyway, if a cap or battery bank is used for storage. The inverter can draw all the pulses it wants. It just has to be big enough to handle the peak. The good thing about them is they are usually parallelable, as solar systems are often scaleable and with redundancy. Need more capacity? Buy another later.
There would be advantage to a 3 phase generator to drive a rectifier load, as the ripple current in your capacitors goes WAY down. 3 phase rectifiers are often run without ANY filtering and produce reasonable DC ripple that way.
There would be advantage to a 3 phase generator to drive a rectifier load, as the ripple current in your capacitors goes WAY down. 3 phase rectifiers are often run without ANY filtering and produce reasonable DC ripple that way.
Single phase would be fine I guess, but I like to have the output as 3 phases with separate breakers to separate critical loads like DJ booth and speakers from lights and stuff. And if it can balance the load so 50% of total can run on one phase, that is very easy to comply to, so the disadvantage of having it split on phases pretty much disappears.
50% running of one side of a single phase system would be “normal” operation. It would take more than 50% to overload one side. And the single phase inverters i was looking at for my home build had load balancing anyway (12 kW).
You ALWAYS want critical loads on a separate breaker, regardless of what feeds it. With something like this they could have their own inverter.
A 3 phase rectifier coming off the generator would need a full size neutral because of the harmonics but it should be a short feed. It matters when going 500 feet and trying to save wire or make it easier to pull in the conduit…..
You ALWAYS want critical loads on a separate breaker, regardless of what feeds it. With something like this they could have their own inverter.
A 3 phase rectifier coming off the generator would need a full size neutral because of the harmonics but it should be a short feed. It matters when going 500 feet and trying to save wire or make it easier to pull in the conduit…..
Good points. It is quite common that systems that will need this kind of solution will expect a 3 phase connection to connect to their distro which already have breakers and their amps connected. I have already configured my rack like that, and it is nice with a direct swap-in for the typical generator solution.
When running on generator maybe 50% on one phase is possible with a good generator, but I always try to balance the load since I been told it makes them run more evenly.
Good point about the neutral, makes sense to keep the inverter close to generator.
However I think I will scrap the idea of running a big 15-20kW inverter from all 3 phases on generator. When looking at the solar inverters I only checked spec on weight which seemed reasonable to fit in a suitable container. However, those things are huge! Definitely not for lugging around even with a reasonable sized cart.
I haven't been able to clarify if UPS mode on the Allpowers R4000 can be bypassed in any way. But there are AC, Solar and EV charger inputs. AC accepts up to 2400w, solar 2000w and EV 2000w, with the total when using AC or EV and solar at the same time is 4000w. It is not specified EV and AC at the same time, but I assume that is not possible since EV is just another AC input, and the limitation of 2000w is simply due to that being the closest amp setting on a charger that matches spec.
So to keep everything going through the inverter I might have to do with only 2000w of charging through solar, using something like a Eltek Flatpack, but hopefully I can supplement the rest through AC or EV without going into UPS mode.
When running on generator maybe 50% on one phase is possible with a good generator, but I always try to balance the load since I been told it makes them run more evenly.
Good point about the neutral, makes sense to keep the inverter close to generator.
However I think I will scrap the idea of running a big 15-20kW inverter from all 3 phases on generator. When looking at the solar inverters I only checked spec on weight which seemed reasonable to fit in a suitable container. However, those things are huge! Definitely not for lugging around even with a reasonable sized cart.
I haven't been able to clarify if UPS mode on the Allpowers R4000 can be bypassed in any way. But there are AC, Solar and EV charger inputs. AC accepts up to 2400w, solar 2000w and EV 2000w, with the total when using AC or EV and solar at the same time is 4000w. It is not specified EV and AC at the same time, but I assume that is not possible since EV is just another AC input, and the limitation of 2000w is simply due to that being the closest amp setting on a charger that matches spec.
So to keep everything going through the inverter I might have to do with only 2000w of charging through solar, using something like a Eltek Flatpack, but hopefully I can supplement the rest through AC or EV without going into UPS mode.
Of course the weight is totally crazy on solar inverters. That’s what it TAKES to be able to put out 6, 12, 18 kW continuously. Remember that about your amplifiers. The weight will tell you what it can continuously put out too. If it weighs 14 pounds, consuming one rack unit, and rated 14,000 watts…. And the less “continuously” it can operate, the more trouble it has with peak loads, poor power supply, or overheating.
A properly balanced 3 phase motor or generator has a constant TORQUE on it, not one that varies from zero to 2X at a 3600 RPM rate. Which is what happens on a single phase motor. Seriously. Its only the mass of the rotor that mitigates this.
A properly balanced 3 phase motor or generator has a constant TORQUE on it, not one that varies from zero to 2X at a 3600 RPM rate. Which is what happens on a single phase motor. Seriously. Its only the mass of the rotor that mitigates this.
Comparing inverters to the amps, the Morin x1304 should be able to deliver 30000w into 2 ohm and weights a little over 10kg.
An inverter with same power rating will probably weight triple, but worst of all be like 10 times as large it seems. For sure not a 1U box, and not even 8U, but a separate behemoth that will require more of a trailer than a trolley
Now the inverter will probably be rated for actual continuous consumption, but the amplifier for RMS or program, so apples and oranges. And when inverters mention peak capacity it is typically for 500ms, so unless you reproduce 1Hz you should require much shorter durations, which never is specified. 500ms is slower than many fuses, so if the amp would require anything near its rating for those durations it would not be able to run on mains either.
If sizing the inverter to handle peak output of amplifier, it seems like using amplifiers as inverters would be much more compact, lightweight and cheaper...so I'm guessing that is wrong, and probably something like a 4000w inverter could handle the x1304. Then the size and weight would be similar, but it would be cheaper. That would correspond quite well to to typical actual draw figures compared to their program rating, which tends to be stated as 1/8, so that is 3750w which really must be the limit for continuous consumption for the amp since it comes with a 16A 240v connection. So a 4000w inverter will probably be fine, especially if running into 4 ohm. If you want to push the last decibel in 2 ohm then a 6000w inverter should mean it doesn't have to run 100%.
Should get the R4000 tomorrow and will be curious to see what kind of output I can get from the 4000w inverter in it. Subs are a few weeks away, but perhaps I need get a dummy load for testing anyway to spare family and neighbours
An inverter with same power rating will probably weight triple, but worst of all be like 10 times as large it seems. For sure not a 1U box, and not even 8U, but a separate behemoth that will require more of a trailer than a trolley
Now the inverter will probably be rated for actual continuous consumption, but the amplifier for RMS or program, so apples and oranges. And when inverters mention peak capacity it is typically for 500ms, so unless you reproduce 1Hz you should require much shorter durations, which never is specified. 500ms is slower than many fuses, so if the amp would require anything near its rating for those durations it would not be able to run on mains either.
If sizing the inverter to handle peak output of amplifier, it seems like using amplifiers as inverters would be much more compact, lightweight and cheaper...so I'm guessing that is wrong, and probably something like a 4000w inverter could handle the x1304. Then the size and weight would be similar, but it would be cheaper. That would correspond quite well to to typical actual draw figures compared to their program rating, which tends to be stated as 1/8, so that is 3750w which really must be the limit for continuous consumption for the amp since it comes with a 16A 240v connection. So a 4000w inverter will probably be fine, especially if running into 4 ohm. If you want to push the last decibel in 2 ohm then a 6000w inverter should mean it doesn't have to run 100%.
Should get the R4000 tomorrow and will be curious to see what kind of output I can get from the 4000w inverter in it. Subs are a few weeks away, but perhaps I need get a dummy load for testing anyway to spare family and neighbours
Had delays with getting the subs, so have not been able to really push the R4000 with the full system yet, but when testing with the sub drivers set up for preconditioning and watching the consumption on the R4000, it seems like I will not have to worry about the continous draw that much.
I'm quite confident that the 4000w will be enough to drive the system which consists of 4 subs with 2000w AES each and 4 tops with 640w, so 10560w total. Typically continous draw will be around 1/8-1/4 of rated, and for example the Morin x-1304 amplifier claims a max draw of 3100w but rated effect of almost 30000w when running 2 ohm. With my speakers in 4 ohm I will run that amp on about 1/3 power, and realisticly I don't think draw for the whole system will exceed 2500w in total, and should have room to scale up the system if needed.
I'm getting chargers to input 2000w to solar and 2000w to car charger, which means the R4000 should be able to work as an online UPS, charging and delivering 4000w continous at the same time, so more than enough to drive the sound and DJ eqipment.
I also found a portable three phase inverter generator, something I didn't think existed after looking around: https://kipor.org/produkt/fme-df-8000-inverter-stromerzeuger-dual-fuel/
Should be capable of 15kW "surge", which is typically measured in seconds rather than ms, so will probably handle the needs of the system on it's own without problem. With the R4000 connected to two of the phases, and the last phase being used for lights, I should have more than enough continous power as well as capacitance for plenty of peak power. And unlike a regular three phase generator, phases does not have to be balanced, other than not exceeding 2.4kW on any phase.
They also have an extension tank making it possible to run the system for very long time without refuel. If I would be pushing it to give continous 6kW, it should run for over 18 hrs. Using propane should only reduce total output by 300w, and using a transfer switch it would be easy to keep it running a whole festival. More expensive to run on propane here though, but also good as a backup if there should be problems with carburettor.
Not a cheap solution, and probably overkill with both the generator and R4000, but will be useful for more than the occasional party and since houses here are connected with three phase, the generator can be connected to power my whole house with clean power if there are power cuts. And with the R4000 I can run the system for a couple of hours at full power as backup, or without using the generator at all for smaller and shorter events. If both lasts 10 years (probably very optimistic), they should pay themselves off in that time if I only use them for a single event per year when compared to rental and fuel cost compared for a Atlas Copco trailer, and hopefully mean less hassle and stress, be less noisy, give cleaner power with more surge capablility and generate less emissions. Probably I will make some more events now when I have my own setup, and perhaps rent it out occasionally, so should pay for itself in a few years I hope.
I'm quite confident that the 4000w will be enough to drive the system which consists of 4 subs with 2000w AES each and 4 tops with 640w, so 10560w total. Typically continous draw will be around 1/8-1/4 of rated, and for example the Morin x-1304 amplifier claims a max draw of 3100w but rated effect of almost 30000w when running 2 ohm. With my speakers in 4 ohm I will run that amp on about 1/3 power, and realisticly I don't think draw for the whole system will exceed 2500w in total, and should have room to scale up the system if needed.
I'm getting chargers to input 2000w to solar and 2000w to car charger, which means the R4000 should be able to work as an online UPS, charging and delivering 4000w continous at the same time, so more than enough to drive the sound and DJ eqipment.
I also found a portable three phase inverter generator, something I didn't think existed after looking around: https://kipor.org/produkt/fme-df-8000-inverter-stromerzeuger-dual-fuel/
Should be capable of 15kW "surge", which is typically measured in seconds rather than ms, so will probably handle the needs of the system on it's own without problem. With the R4000 connected to two of the phases, and the last phase being used for lights, I should have more than enough continous power as well as capacitance for plenty of peak power. And unlike a regular three phase generator, phases does not have to be balanced, other than not exceeding 2.4kW on any phase.
They also have an extension tank making it possible to run the system for very long time without refuel. If I would be pushing it to give continous 6kW, it should run for over 18 hrs. Using propane should only reduce total output by 300w, and using a transfer switch it would be easy to keep it running a whole festival. More expensive to run on propane here though, but also good as a backup if there should be problems with carburettor.
Not a cheap solution, and probably overkill with both the generator and R4000, but will be useful for more than the occasional party and since houses here are connected with three phase, the generator can be connected to power my whole house with clean power if there are power cuts. And with the R4000 I can run the system for a couple of hours at full power as backup, or without using the generator at all for smaller and shorter events. If both lasts 10 years (probably very optimistic), they should pay themselves off in that time if I only use them for a single event per year when compared to rental and fuel cost compared for a Atlas Copco trailer, and hopefully mean less hassle and stress, be less noisy, give cleaner power with more surge capablility and generate less emissions. Probably I will make some more events now when I have my own setup, and perhaps rent it out occasionally, so should pay for itself in a few years I hope.