Uninterruptible Power Supplies

I was just about to bite the bullet & shell out for one of  these units and then I read a couple of customer reviews on Amazon which put me off Oxxtron, so I'm now looking at APC, though I don't want to spend a fortune on it and don't really know the load I'm drawing.

My entire studio (DAW, Console, Outboard, Keyboards) are essentially all powered from one wall socket, though this splits out into a pseudo star system using several 6-way distribution blocks.

What's the easiest way to calculate (or measure) the total load on the system so I can spec a suitable APC UPS?

Thanks

I have my equipment - PC, Roland Octa Capture and a couple of small power requirement devices all on UPS.  If I were doing a recording session and only had the PC connected and got a short power glitch/dropout it could still interrupt a recording session if I only had the PC connected.

APC and Cyberpower seem to be the two main "consumer" UPS vendors here in the US.  

One thing to consider, thanks to the EU requirement, is that new/recent PC power supplies are "PFC" type.  Many PFC power supplies require either a true sine wave output from the UPS (when on backup battery power) or that the UPS has a less than 4ms switching time.  If the UPS does not meet one of those spec's many PFC power supplies will fail (will power off) when the UPS is switching to backup battery power.

Bristol_Jonesey


I was just about to bite the bullet & shell out for one of  these units and then I read a couple of customer reviews on Amazon which put me off Oxxtron, so I'm now looking at APC, though I don't want to spend a fortune on it and don't really know the load I'm drawing.

My entire studio (DAW, Console, Outboard, Keyboards) are essentially all powered from one wall socket, though this splits out into a pseudo star system using several 6-way distribution blocks.

What's the easiest way to calculate (or measure) the total load on the system so I can spec a suitable APC UPS?

Thanks

If you're running everything off of one wall socket, then you can estimate how much power you're using simply by checking the breaker rating on that circuit.  if it's a 15A breaker (typical - some bay be 20A for household use) then you're using 230V X 15A = 3450W.  (NOTE:  I know that Colin is in the UK so his voltage is 230V, if you're in the USA your house voltage is 120V).
 
that will be a conservative estimate (more than you're actually using) because a) you're only using 1 wall socket and that breaker will cover more than just one  and b) you're not tripping the breaker (or at least you didn't say you were) so you're not using the full 15A yet anyway.

The rating of a wall socket does not tell you anything about how much power you are using. It is telling the maximum amount of power you can use. eg my wall socket is 240 V rated at 10 amps which translates into 2400 watts but I am only drawing much less than that. eg 400 or 600 watts or so. Just as a computer is also not necessarily drawing the amount of power the power supply is rated at. The power supply inside your computer is the maximum power it can supply and most often the computer will be drawing less than that.

The only way to do it effectively is to measure the current in line and you can do that with the correct device. Adding up the total power consumption on all your gear might bring you into the ballpark although some of those ratings might be in maximum power draw situations eg your active monitors going flat out but most of the time they are not. 

I don't agree with jcschild below re using more than one circuit.  Unnecessary if the total power consumption of your entire studio is well under the maximum you can draw from one wall socket. In fact for earthing reasons and earth hums it is better. But if I were running a 1000 watt radiator or similar I would definitely plug that into its own circuit.

Bristol I don't like turning the entire studio on with one switch. It is not actually a smart idea at all. Firstly you will give the switch contacts a serious workout every time you do it and that could wear out. Also everything coming on at once might create a power situation/surge that some things may not like or even get damaged.

I have got a power board connected to the one wall socket but with 4 switches on it. I have got my studio wired up to 4 circuits. My computer goes direct to 24/7 power and gets power all the time. I did design and build a power filter though which has a frequency response only up to and slightly above the mains frequency. I am sure that helps a lot. (I still power it off when not in use) That way even if all 4 switches are switched off (by someone else that is) and the computer is doing something important it will never get power shut off in the middle.

Circuit 1 feeds a spare extension cord now which is not used. Circuit 2 feeds the mixer and some basic important power feeds to to my laptop etc. Circuit 3 feeds a six foot rack with everything in it and circuit 4 feeds just the monitor system. That way I can turn them all on of course and sequentially but also I can leave stuff off that I may not necessarily use. eg to do a computer backup I don't need any circuits on or to just do some editing on phones circuit 2 only etc.. You will save power by switching parts of your studio on that you only need at any given time. Think about what things you actually need to do any particular job and put those items on the same circuit. It works very well. 

As far as the UPS thing I tend to think they are only really helpful if you in an area prone to power failures. If you are not you may not need it at all. The price of that unit also looks too cheap for me as well. I did some research on this a while back and found out the units that really work cost much more eg over $1000 for about a 1200watt unit but it was a serious quality unit though.

1) running everything off one circuit never mind one plug is not good. you should have minimum 2 x 15 amp circuits (or 20 amp)

also depends on how much gear you have.

ideally you have 1 UPS for computer and LCDs and another for the rest.

Tripp lite is who i prefer or Ultra for the larger units.  APC is too pricey.

typical computer. 700W power supply, 2 x LCDs @ 75 watt each (really more like 25watts but safe is better)
so just for those items you need 850W UPS.  NOTE watts do not equal VA.. a 1000 VA UPS is not good enough for 850W..

also Brown outs/Dirty power are far more common and far more damaging than spikes. so you really need a line interactive UPS.
(this keeps the volts the same no matter what your power does..  well to a point of course.)
something like the tripp lite OMNIVS1500 its 940W.

for higher wattage than that the Ultra ULT33046 2000VA

its generally cheaper to buy 2 smaller UPS than 1 large one for more wattage than 1200 it gets really expensive.


you need to add up all the wattage of your items to find out.. just knowing your plug is 15 Amp dont tell you jack..
which BTW is only good for 1800 Watts

Thanks guys, lots of information to absorb and different strategies to explore.
@ Beagle - Reece, I know you weren't ranting at me mate, besides, I like your rants!
@ Jeff - I should have qualified what I meant by  "switching the entire studio on with one switch". It's true that it's all powered from one socket, but when I switch on initially, all this does is power up my rack, desk, monitors (video) & interface. Then I power up the pc, then finally my monitors (audio)

The important devices to have protected are the computer (obviously) and video monitors.

UPS's I have looked at talk about a 4ms switchover time. Is this quick enough to protect my pc?

With regards to how many amps one really needs:

from: http://www.furmansound.co...v=03&id=AC_CURRENT

"Q: I understand each of my power amplifiers require a 20 amp circuit, and that my power amplifiers can draw as much as 50 amps! Won't I have a problem with a 15 or 20 amp AC power conditioner shutting down?


A: It’s VERY unlikely. What the amplifier manufacture has failed to explain is that they are concerned with peak current draw, not RMS current draw. There are very few power amplifiers manufactured regardless of price or topology that will exceed 5 amps RMS at FULL VOLUME! Typically, it’s half that amount."

Also, look for one that connects to your PC (usually USB).  Windows will detect it and allow you to set up what/when to "orderly" shutdown the PC.   This is good for times when the PC is powered on but unattended.