Hi,
I am planning a mobile PA video thingy for festivals big, small, new and old. So i probably run into lightning, generator & cablelength voltage drop problems. I dont want to send problems with my gears powersupply to the next fellow on the festival. The do no evil part. It's all inside a small marque, audience 2/3 distance seating is at 4 meter. So no big poweramps needed.
I am a bit stuck in how to protect my gear at a reasonable cost, weight and ease. I am into speakers and "video", not a big whizz on making my own circuitry. Off the shelf solutions would be the way to go, for me.
The set-up
My questions, noob on electricity... bare with me
1. Would a different kind of powersupply on the amplifier make a difference? So i could use it in the AC guard 16A 230V group? And use a smaller UPS for only projector and BR player? Big savings on weight and money there. Thereby changing the function of the AC guard to protection of gear and loose sound when power fails.
2. Are switching powersupplies really that prone to problems with wildly varying voltages? Compared to transformer based ones?
3. Are there other 16A 230V protectors? lighter in weigth, cheaper, faster switch back time's. Google thinks Sollatek is the go to brand...
4. Would a Sollatek voltage stabiliser help in doing no evil to others on the festival ground? For my switching powersupply gear
5. Anything i miss in this? Please do comment!
Running everything on batteries is not an option
Many thanks in advance! My head is somewhat spinning from all these options!
I am planning a mobile PA video thingy for festivals big, small, new and old. So i probably run into lightning, generator & cablelength voltage drop problems. I dont want to send problems with my gears powersupply to the next fellow on the festival. The do no evil part. It's all inside a small marque, audience 2/3 distance seating is at 4 meter. So no big poweramps needed.
I am a bit stuck in how to protect my gear at a reasonable cost, weight and ease. I am into speakers and "video", not a big whizz on making my own circuitry. Off the shelf solutions would be the way to go, for me.
The set-up
- 4 x 200 Watt @4 Ohm Class AB switching power suply (1.4 factor for eff) 1.120 Watt
- Projector bulb type total power consumption 370 Watt
- BR player 12 Watt
- Popcorn machine 860 Watt 8 Oz type
- Airconditioner 12.000 Btu, high Seer inverter type 1.100 Watt
- All lights are leds attenuated with a led dimmer pack less then 150 Watt
My questions, noob on electricity... bare with me
1. Would a different kind of powersupply on the amplifier make a difference? So i could use it in the AC guard 16A 230V group? And use a smaller UPS for only projector and BR player? Big savings on weight and money there. Thereby changing the function of the AC guard to protection of gear and loose sound when power fails.
2. Are switching powersupplies really that prone to problems with wildly varying voltages? Compared to transformer based ones?
3. Are there other 16A 230V protectors? lighter in weigth, cheaper, faster switch back time's. Google thinks Sollatek is the go to brand...
4. Would a Sollatek voltage stabiliser help in doing no evil to others on the festival ground? For my switching powersupply gear
5. Anything i miss in this? Please do comment!
Running everything on batteries is not an option
Many thanks in advance! My head is somewhat spinning from all these options!
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Amplifiers are the least of your problems.
I shudder thinking about the AC system and the popcorn machine, **big** problem is that they will not run continuously but turn on/off all the time, triggered by their own thermostats.
Problem is that this is not the City power supply, but a small power generator.
In a City stuff is turning on/off all the time, but the average is ... well ..... average, it sort of evens out.
But when your AC turns on, which to boot is an electric motor based device , it will "eat" all of your power capacity ,even if for a second, so generator detector will speed up the motor to compensate ... that takes seconds ... then it will find power consumption has stabilized and slow it down.
Then the opposite when AC turns off; with the popcorn machine doing the same in a smaller scale.
The point is that your AC will be very unstable, because largest consumers go on/off all the time.
Personally, I'd run TWO generators: a smaller one only for amps and sensitive equipment which needs *stable* voltage, and a larger one for stuff which can stand rollercoaster type voltage,at least popcorn and AC .
Flip a coin for lighting and projector, although I'd also put them no the larger one.
OR, rent one of these:
Not kidding, and you might share it with others.
I run live Rock shows regularly,and have used both approaches, either the two smaller ones or a rented large beast.
Also repair lots of stuff blown by generators going wild.
The big problem is not the brownout, but generator trying to compensate and then one big power consumer turning off.
We use 220V lines and I have measured peaks as high as 270/280VAC many times, lasting for over 10/15 seconds ... few can stand that.
And if you stand by the generators you'll hear them speed up/down all the time.
I shudder thinking about the AC system and the popcorn machine, **big** problem is that they will not run continuously but turn on/off all the time, triggered by their own thermostats.
Problem is that this is not the City power supply, but a small power generator.
In a City stuff is turning on/off all the time, but the average is ... well ..... average, it sort of evens out.
But when your AC turns on, which to boot is an electric motor based device , it will "eat" all of your power capacity ,even if for a second, so generator detector will speed up the motor to compensate ... that takes seconds ... then it will find power consumption has stabilized and slow it down.
Then the opposite when AC turns off; with the popcorn machine doing the same in a smaller scale.
The point is that your AC will be very unstable, because largest consumers go on/off all the time.
Personally, I'd run TWO generators: a smaller one only for amps and sensitive equipment which needs *stable* voltage, and a larger one for stuff which can stand rollercoaster type voltage,at least popcorn and AC .
Flip a coin for lighting and projector, although I'd also put them no the larger one.
OR, rent one of these:
Not kidding, and you might share it with others.
I run live Rock shows regularly,and have used both approaches, either the two smaller ones or a rented large beast.
Also repair lots of stuff blown by generators going wild.
The big problem is not the brownout, but generator trying to compensate and then one big power consumer turning off.
We use 220V lines and I have measured peaks as high as 270/280VAC many times, lasting for over 10/15 seconds ... few can stand that.
And if you stand by the generators you'll hear them speed up/down all the time.
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Thanks!
Could three phase power be a solution? One phase for the popper and the AC, one phase lights, one phase sound and image? Any experience with UPS use? AVR on the UPS. I did some research into the Airconditioner types, the type i would like to use is a Inverter type, these come with softstart and without the current inrush compared with the on / off compressor type.
Looks nice, but still have the feeling i don't quite get or understand all the problems i will encounter. Help still welcome!
Could three phase power be a solution? One phase for the popper and the AC, one phase lights, one phase sound and image? Any experience with UPS use? AVR on the UPS. I did some research into the Airconditioner types, the type i would like to use is a Inverter type, these come with softstart and without the current inrush compared with the on / off compressor type.
Looks nice, but still have the feeling i don't quite get or understand all the problems i will encounter. Help still welcome!
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The loads that matter are the popcorn and the aircon, the audio is a noddy little load.
Personally I would hire in a super silenced entertainment grade machine good for ~25Kva or so (plus a spare if appropriate) and appropriate distribution equipment and then stop worrying about it, 25Kva being about the smallest that properly silenced machines with an AVR come.
Small machines are often trouble, where a proper diesel machine of reasonable size and fitted with an AVR will produce something substantially indistinguishable from normal mains.
One thing that does help is to hang a few kw of more or less resistive load as a baseline, site lighting is good for this.
The cheap way to bodge this is to bring in a good quality inverter genset (Honda for preference) for the audio and LED loads (A 2KVA set should do), note most of these are petrol which your site safety guys may well have a problem with, and a larger cheap machine for the aircon and heater loads, but that really is a hack.
If you are running more then one machine, think most carefully about the grounding arrangements, this gets complicated (and very much subject to local regs) quickly.
For the UK, BS7909 is the appropriate standard to work to, other places have other temporary power standards.
I would note that most festivals have power organised centrally, you tell the festival organiser what you need and they organise appropriate machines and distribution cabling, usually contracting the work to a temporary power specialist.
Regards, Dan.
Personally I would hire in a super silenced entertainment grade machine good for ~25Kva or so (plus a spare if appropriate) and appropriate distribution equipment and then stop worrying about it, 25Kva being about the smallest that properly silenced machines with an AVR come.
Small machines are often trouble, where a proper diesel machine of reasonable size and fitted with an AVR will produce something substantially indistinguishable from normal mains.
One thing that does help is to hang a few kw of more or less resistive load as a baseline, site lighting is good for this.
The cheap way to bodge this is to bring in a good quality inverter genset (Honda for preference) for the audio and LED loads (A 2KVA set should do), note most of these are petrol which your site safety guys may well have a problem with, and a larger cheap machine for the aircon and heater loads, but that really is a hack.
If you are running more then one machine, think most carefully about the grounding arrangements, this gets complicated (and very much subject to local regs) quickly.
For the UK, BS7909 is the appropriate standard to work to, other places have other temporary power standards.
I would note that most festivals have power organised centrally, you tell the festival organiser what you need and they organise appropriate machines and distribution cabling, usually contracting the work to a temporary power specialist.
Regards, Dan.
Hi,
Thanks! I do understand that buying or renting my own generator would solve all the problems. How to protect the gear when this is not possible? And i have to do with what is on site? Not to be annoying, but to cover all possible scenario's. Even with a perfect two generator set-up, people still can trip over a powerline and unplug it, lightning can strike. How to prevent this killing my gear?
I see the popcorn popper as a heater. With a small stirring motor. Wrong? Do these machine's have high inrush current? And if so, would that be something that can be fixed? Softstart popcorn popper?
Thanks! I do understand that buying or renting my own generator would solve all the problems. How to protect the gear when this is not possible? And i have to do with what is on site? Not to be annoying, but to cover all possible scenario's. Even with a perfect two generator set-up, people still can trip over a powerline and unplug it, lightning can strike. How to prevent this killing my gear?
I see the popcorn popper as a heater. With a small stirring motor. Wrong? Do these machine's have high inrush current? And if so, would that be something that can be fixed? Softstart popcorn popper?
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The problem is that heaters demand a lot of current. Heater switches on and demands 10A (for example). Generator is only supplying 2A at the time, so needs to really put some work in to maintain something that's now demanding 6x the current. After a few seconds, everything has spun up and is working harder.
No real problems there - the lights might go dim for a second, but most amps won't notice or care.
When the heater switches off, you have a problem. The generator is now working for the 12A supply, but now only 2A is being drawn. Voltage goes high while the components reduce speed. In some cases, the voltage will be high enough to start destroying things. Imagine putting 100v across a 63v cap and you're there.
IMO, your best bit is an old boat anchor amp that just doesn't care what you do to it. I have a QSC USA850 that fits that description.
The alternative is, if you're running a 110v system, find an amp that has a universal power supply - usually an IEC input, and will run on 100-250v just fine, thanks to switch-mode technology. That will save you from a 150v input from a 110v generator going high-voltage, but won't save you from 280v from a 230v generator.
Chris
No real problems there - the lights might go dim for a second, but most amps won't notice or care.
When the heater switches off, you have a problem. The generator is now working for the 12A supply, but now only 2A is being drawn. Voltage goes high while the components reduce speed. In some cases, the voltage will be high enough to start destroying things. Imagine putting 100v across a 63v cap and you're there.
IMO, your best bit is an old boat anchor amp that just doesn't care what you do to it. I have a QSC USA850 that fits that description.
The alternative is, if you're running a 110v system, find an amp that has a universal power supply - usually an IEC input, and will run on 100-250v just fine, thanks to switch-mode technology. That will save you from a 150v input from a 110v generator going high-voltage, but won't save you from 280v from a 230v generator.
Chris
Most audio loads are highly variable in nature. They'll draw 2A all the time and 12A on every kick drum hit. If the audio is a large fraction of the total load on the generator you'll be getting those wild swings in output voltage repeatedly - not just every time the heating elements turn off.
There would still be a gap or an overlap - and the spike could be just a s bad. Shorter duration maybe. Overbuilt boat anchor amps can handle it better than modern stuff. Better solution is overkill on the genny. We used 5kW Honda for 800 watts of audio. Ran fine. 2.8kW genny couldn't handle it - and sent the governor into a tailspin. That's why some were recommending a rented 10-20kW diesel. It would stay more steady in the face of a varying load, because it would be lightly loaded regardless.
Some slight misunderstandings here, generators do NOT (typically) speed up or slow down significantly depending on load, the shaft speed sets the frequency, and is maintained substantially constant by the engine governor.
It is the field current that sets the terminal voltage, assuming a proper machine (The very cheap building site crap uses a compound wound alternator and can indeed be all over the shop), in a decent machine the field is controlled electronically by the automatic voltage regulator electronics to maintain terminal voltage.
As to how you protect your gear, for gross faults, there is always insurance.....
Other then that, a shunt trip breaker and voltage and frequency relays to trip things out in the event of a serious voltage or frequency excursion (The latter often caused by a blocked fuel filter).
It is the field current that sets the terminal voltage, assuming a proper machine (The very cheap building site crap uses a compound wound alternator and can indeed be all over the shop), in a decent machine the field is controlled electronically by the automatic voltage regulator electronics to maintain terminal voltage.
As to how you protect your gear, for gross faults, there is always insurance.....
Other then that, a shunt trip breaker and voltage and frequency relays to trip things out in the event of a serious voltage or frequency excursion (The latter often caused by a blocked fuel filter).
But the cheap job site generators are what people use. With intermittant heavy loads the governors can't maintain speed control without overshoot/undershoot, sending voltage and frequency all over the place. Toroid transformers really get upset when the frequency momentarily drops to 30 Hz.
"A decent machine" is a rented diesel. A $499 Home Depot Special will do if (and only if) the load is relatively light for the size, all your front end electrincs are on a power conditioner, and the amps are built like tanks (but not too big). Think old 1978-vintage CS800 or a home brew version.
"A decent machine" is a rented diesel. A $499 Home Depot Special will do if (and only if) the load is relatively light for the size, all your front end electrincs are on a power conditioner, and the amps are built like tanks (but not too big). Think old 1978-vintage CS800 or a home brew version.
I have not seen a job site generator on a festy site for a long, long time (Except possibly powering an RV, or a kettle during build and break).
There are rented diesel sets, but the other option are the small inverter petrol machines, some fire risk from the fuel, but with the better sort the output is clean and they are quiet and compact.
These generally do not cope well with refrigeration compressor startup transients, but for small audio loads are probably the best option if the highly flammable fuel is not a show stopper for you.
I had a 6KVA class Honda diesel that was ok, single phase, acoustically a bit loud, but with an AVR that I would not be too bothered by for this sort of job, but that was a few thousand pounds to buy.
That rented diesel in either road tow or skid mount is not actually THAT expensive to hire, and means you can get on with the gig without having to think about power issues.
Depending on where you are the local council may demand paperwork, or the AHJ may demand that suitable cables (Which in the US does NOT usually mean home depot orange) be used.
73 Dan.
There are rented diesel sets, but the other option are the small inverter petrol machines, some fire risk from the fuel, but with the better sort the output is clean and they are quiet and compact.
These generally do not cope well with refrigeration compressor startup transients, but for small audio loads are probably the best option if the highly flammable fuel is not a show stopper for you.
I had a 6KVA class Honda diesel that was ok, single phase, acoustically a bit loud, but with an AVR that I would not be too bothered by for this sort of job, but that was a few thousand pounds to buy.
That rented diesel in either road tow or skid mount is not actually THAT expensive to hire, and means you can get on with the gig without having to think about power issues.
Depending on where you are the local council may demand paperwork, or the AHJ may demand that suitable cables (Which in the US does NOT usually mean home depot orange) be used.
73 Dan.
Thanks for all the replies! So would this thing help me protect my gear? At least against spike's and overvoltage?
Techical Specification Type of control Micro processor Input Range 230Vac -29% to +23% Output Disconnect Voltage Low = 185 V
High = 264 V Correction Speed Low = 0.5 s
High = 2.0 s Surge / Spike Response Within 10 Nanosecond Frequency 45-75Hz Connection Direct Wiring 6 mm²
And how about these?
Microprocessor Controlled Voltage Stabilisers - SVS Range
From Sollatek, the Voltright SVS range of voltage stabilisers protects electrical equipment by monitoring the mains voltage and stabilising any rises or drops, ensuring a constant voltage and suppressing any surges or spikes. The SVS series accommodates voltage fluctuations across a very wide range, and maintains an output voltage that is accurate to within fine tolerances. The Voltright voltage stabiliser have microprocessor controlled operation resulting in extremely fast reaction times.
Suitable for all electronic and electrical devices, Sollatek voltage stabilisers are particularly useful in applications such as medical refrigeration and air conditioning.
Features and Benefits:
• All-electronic construction with no moving parts
• Easy to install and has a small foot print
• Input Range: 230Vac -29% → +23%
• Output Accuracy: Input = 171 → 275V, Output = 230Vac ± 6%, Input = 164 → 171V, Output = 230Vac ± 10%, Input = 274 → 285V, Output = 230Vac ± 10%
• Correction Speed: 750Volts / Second
• Response Within 15 Millisecond
• Wave form distortion: None
• Electronic switching
• Frequency: 45-75Hz
I do understand, the above gadget would not compensate for powerloss in Ampere. But no use at all? To protect my gear?
I now know what to rent if i need a generator. How would you specify you power needs to a festival that rents you? With this setup? 230 Volt territory. 2 x 16A 230 nobody elso on the cable / connection. Maybe 400 Volt 16A? Invertertype generators?
Regards Phenoholic
An externally hosted image should be here but it was not working when we last tested it.
Techical Specification Type of control Micro processor Input Range 230Vac -29% to +23% Output Disconnect Voltage Low = 185 V
High = 264 V Correction Speed Low = 0.5 s
High = 2.0 s Surge / Spike Response Within 10 Nanosecond Frequency 45-75Hz Connection Direct Wiring 6 mm²
And how about these?
Microprocessor Controlled Voltage Stabilisers - SVS Range
From Sollatek, the Voltright SVS range of voltage stabilisers protects electrical equipment by monitoring the mains voltage and stabilising any rises or drops, ensuring a constant voltage and suppressing any surges or spikes. The SVS series accommodates voltage fluctuations across a very wide range, and maintains an output voltage that is accurate to within fine tolerances. The Voltright voltage stabiliser have microprocessor controlled operation resulting in extremely fast reaction times.
Suitable for all electronic and electrical devices, Sollatek voltage stabilisers are particularly useful in applications such as medical refrigeration and air conditioning.
Features and Benefits:
• All-electronic construction with no moving parts
• Easy to install and has a small foot print
• Input Range: 230Vac -29% → +23%
• Output Accuracy: Input = 171 → 275V, Output = 230Vac ± 6%, Input = 164 → 171V, Output = 230Vac ± 10%, Input = 274 → 285V, Output = 230Vac ± 10%
• Correction Speed: 750Volts / Second
• Response Within 15 Millisecond
• Wave form distortion: None
• Electronic switching
• Frequency: 45-75Hz
I do understand, the above gadget would not compensate for powerloss in Ampere. But no use at all? To protect my gear?
I now know what to rent if i need a generator. How would you specify you power needs to a festival that rents you? With this setup? 230 Volt territory. 2 x 16A 230 nobody elso on the cable / connection. Maybe 400 Volt 16A? Invertertype generators?
- 4 x 200 Watt @4 Ohm Class AB normal power suply boat anchor type amp. (1.4 factor for eff) 1.120 Watt maximum peak
- Projector bulb type total power consumption 370 Watt continuous
- BR player 12 Watt continuous
- Popcorn machine 860 Watt 8 Oz type on/off
- Airconditioner 12.000 Btu, high Seer inverter type 1.100 Watt continuous
- All lights are leds attenuated with a led dimmer pack less then 150 Watt on /off
Regards Phenoholic
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No.
get proper voltage, period.
Those lightweight so called "stabilizers/protectors" are meant for lightweight stuff, think computers and such, I'd *love* to see them burst in flames trying to compensate for an AC motor inrush current, specially if the compressor is stalled in a deadpoint or a high compression part of the cycle.
get proper voltage, period.
Those lightweight so called "stabilizers/protectors" are meant for lightweight stuff, think computers and such, I'd *love* to see them burst in flames trying to compensate for an AC motor inrush current, specially if the compressor is stalled in a deadpoint or a high compression part of the cycle.
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