OK what to name this topic..?? ..Amperage needed to run...

Hello all, I thought I would post this inquiery here hoping that someone could help. A warning first :D I am not an electrical guru at all , so this might even be a strange (stupid) question. OK...what I'm trying to figure out is what sort of power is needed to run certain pieces of gear. I would like to plan ahead how many AMPs I'll need on certain circuits (does that make sense :? ) before I decide how much power I need to bring to the studio. How do you determine what sort of Amperage (??) a piece of gear requires?? I looked up so many manuals and spec sheets but none mention anything about this. Or can this be worked out of the given Voltage, freq. etc.?? So basically I would like to work out what sort of power my gear will be sucking out of the electrical. How can I determine these factors?? I hope the post makes some sense. Thanks very much!

Hello Sen, As far as amps, believe it or not, most recording gear such as outboard stuff is usually rated in mA. It's not until you get to large consoles, 2 inch tape machines, amplifiers and guitar amplifiers, where you may have a higher amperage. Depending on how large your facility is or if your doing a project studio. In a small studio, you probably won't use more than 60 amps. In a large commercial multi room facility, you may have multiple 200 amp panels. (I'm not familiar w/ Australia's power use, so I really don't know how it's set up...110v, 220v, etc.) :? John will have a better insight for you on this. Aaron

A lot of gears operating power is listed as wattage so you have to just do the math to convert it to find out what the current draw (amperage) is

giles117 wrote:

A lot of gears operating power is listed as wattage so you have to just do the math to convert it to find out what the current draw (amperage) is

yeah that's what I was saying...how do you covert?? :( I'm really not familiar with these types of formulas at all :( Thanks for the input guys and Aaron, that's a pretty good general guidence of power consumption in studios. Thank you for that... As giles said, if I could somehow calculate what each piece needs then I would be happier...but those general guidelines are good too. I probably won't have more than 20 outboard rack units at the start and my Console is not too big either (Tascam 3500)..however I would like to allow for future upgrades and additions..Just not sure if single phase will be enough for the whole place.. :( thank you guys again :) cheers

Many apologies, i should have posted the law it's Ohms Law whereas.... P = Wattage (power) E = Volts I = Amps R = Resistance or ohms so.... if you have the wattage and you know your voltage you can figure out the Current draw thusly: I = P/E If you;d like to know more here is a nice chart Having been a DIY'er (I've built amplifiers and mic pre's, etc..) an electronics repair tech concurrently while mixing FOH and being a DJ this has come in handy many a day especially on the road putting together a live PA and having to balance the loads, etc... and figure out power draw for the system. When on tour and in one of those little halls in meridian, MS before they upgraded the Theatre. :) Have fun.

Also in most audio application. Single Phase is all you need. I have run Large PA rigs covering 10,000 plus folks and all I needed was a 200 Amp single phase main breaker. And we might have drawn 120 Amps max in the heat of the show which is about 60% of the rated box. :) So certainly for the low current consumption this gear nowadays draws that will be adequete. So yeah, never fear. Also when designing a system and you have an estimate of your power load, ALWAYS as a rule (the good old boys taught me this one) ALWAYS leave a power headroom of at least 30%, or to state it another way never use more that 70% of the rated current draw of the breaker you have the gear on. :) A Good rule is to have each outlet in your studio on a separate breaker. 20amp or 30amp. and except for faulty equipment you will probably never run out of juice. :) My Little control room as 4 circuits in it. and I prolly draw no more than 15 amps for everything I am running.

giles117 wrote:

Many apologies, i should have posted the law it's Ohms Law whereas.... P = Wattage (power) E = Volts I = Amps R = Resistance or ohms so.... if you have the wattage and you know your voltage you can figure out the Current draw thusly: I = P/E

thanks a lot giles..once I saw all these "i" , "r" etc. it started coming back to memory...I finished high schooil in Europe and we had U=voltage...anyway thanks very much

If you;d like to know more here is a nice chart

sorry, which one..? :?

Also when designing a system and you have an estimate of your power load, ALWAYS as a rule (the good old boys taught me this one) ALWAYS leave a power headroom of at least 30%, or to state it another way never use more that 70% of the rated current draw of the breaker you have the gear on.

yep, I was allways gonna do that :)

My Little control room as 4 circuits in it. and I prolly draw no more than 15 amps for everything I am running.

would you mind just giving me a rough idea of what you're currently using ?? Thanks a lot

Sorry giles I realized I wasn't logged in and that's probably why I didn't see the chart.I see it now :) Thank you The "log me in automatically each visit" option is not working...? :( thanks cheers

Sen, keep in mind that so far all the "yanks" who've responded are used to 120 volt USA wall power; your 240 volt single phase would take exactly HALF the amperage to run the same amount of stuff. Another example - when my studio was still intact, I ran two smaller mixers (probably about equal to a 3500), 3 midi keyboards, 3 drum machines, a set of electronic drums, a DAW with 21" CRT, about 10 other midi modules, an 8 x 8 midi patch bay, 3 digital reverbs, a Tascam 38 1/2" 8 track, 3 cassette decks (2 dual for dubs, 1 single), a do-everything guitar processor, and probably half a dozen other rack units I'm forgetting, as well as a Hammond with the big 822 leslie - ran the whole thing off one 20 amp circuit at 120 volts, and quiescent power draw was less than 10 amps, not including power amp or lights - I'm not suggesting you try to get by on that little power, the lights dimmed slightly when I turned the power amp on (but I still had the full 120 volts once the power supply had stabilized) - Point is, you're running twice the voltage so would use half the current for the same power usage. Also, since you don't have two phases to choose from you won't have to worry about which one's to use for lights, etc - just don't put a frig on the circuit with your studio stuff unless you like pops and clicks in your tracks. Hope that helped... Steve

knightfly wrote:

Sen, keep in mind that so far all the "yanks" who've responded are used to 120 volt USA wall power; your 240 volt single phase would take exactly HALF the amperage to run the same amount of stuff.

Thanks for the "warning" Steve :) I did realize you guys are on different voltage (I thought it was 110)

Another example - when my studio was still intact, I ran two smaller mixers (probably about equal to a 3500), 3 midi keyboards, 3 drum machines, a set of electronic drums, a DAW with 21" CRT, about 10 other midi modules, an 8 x 8 midi patch bay, 3 digital reverbs, a Tascam 38 1/2" 8 track, 3 cassette decks (2 dual for dubs, 1 single), a do-everything guitar processor, and probably half a dozen other rack units I'm forgetting, as well as a Hammond with the big 822 leslie - ran the whole thing off one 20 amp circuit at 120 volts, and quiescent power draw was less than 10 amps, not including power amp or lights -

thats good news Steve...thanks :)

Also, since you don't have two phases to choose from you won't have to worry about which one's to use for lights, etc - just don't put a frig on the circuit with your studio stuff unless you like pops and clicks in your tracks.

Well at some stage I even thought of putting three phase in there, but I more and more think that i won't need it...much cheaper too (the most important thing at the mom) :roll: Yep there won't be any friges on the same circuit...shoul I also throw the air con on a different one as well?

Hope that helped... Steve

It did indeed Thank you very much Steve :!: cheers

shoul I also throw the air con on a different one as well?

Yep.

Agreed, different circuit - and, if you can find some heavy duty surge suppressors I'd plug your AC AND the Frig into them, even though they're on a different circuit (still the same ground, and ultimately the same transformer coming into the place) - by putting the suppressors across the power for the AC and frig, you should reduce any spiking that may spill into the power distribution in general. (You can always try the setup without suppressors, but may find them necessary if you get any pops or clicks in your studio monitors...) Steve

Me Three, Yeah Put all that other junk on another leg of power. Each Hot is a leg so in three phase you have a Ground, a neutral and 3 hots. Basically. And by isolating the Hot for a specific task you lessen the risk of current build up on the ground leaking into you precious audio side chain and generating that annoying bu=zz thing. Now for the ultimate.... Transformer isolate the audio Power lines. :) That is my fav. You actually control the voltage a lot better that way and end up with really clean power. :)

knightfly wrote:

Agreed, different circuit - and, if you can find some heavy duty surge suppressors I'd plug your AC AND the Frig into them, even though they're on a different circuit (still the same ground, and ultimately the same transformer coming into the place) - by putting the suppressors across the power for the AC and frig, you should reduce any spiking that may spill into the power distribution in general. (You can always try the setup without suppressors, but may find them necessary if you get any pops or clicks in your studio monitors...) Steve

Great info..thank you Steve again :!: So how would you plug things into those suppressors? Is the gear connected to those directly, or do you wire your power points to these suppressors? Excuse the ignorance please :(

Me Three, Yeah Put all that other junk on another leg of power. Each Hot is a leg so in three phase you have a Ground, a neutral and 3 hots. Basically. And by isolating the Hot for a specific task you lessen the risk of current build up on the ground leaking into you precious audio side chain and generating that annoying bu=zz thing.

well yeah those were the thoughts , but that would really be a rather expensive exercise for me to bring the 3 phase in. (I've been told around $2500 AUD just to connect the 3 phase :( ) And doing something like this would be more of a thing that you'd see in building commercial facilities, while I'm only building a home/project thing. But hey you never know, a couple of nice projects done and I could even save for the 3 phase :)

Now for the ultimate.... Transformer isolate the audio Power lines. That is my fav. You actually control the voltage a lot better that way and end up with really clean power

Now ... I don't get that "transformer isolation" thing.. How would that be done :?: Thank you everyone so much 8) cheers

Sen, if your AC is one of the small window types you would just buy a surge suppressor (hopefully they have them in Oz) and plug the AC ONLY into it - that way, any spikes generated by the AC turning on or off will be attenuated by the suppressor. There's an old saying; "The best way to get rid of noise is to NOT generate it in the FIRST place" - Same goes for Refrigerators - when their compressor turns on and off, you get spikes generated that will be seen on the mains supply. By plugging the offending device into a suppressor which is then plugged into the mains, those spikes will be reduced BEFORE they ever get to the mains, so will affect other stuff plugged into that supply FAR less. For heavier loads, such as split HVAC units, you would need to have an electrician wire suppressors (called MOV's) into all legs of the power right where the unit is connected to the mains. For anything less than a large professional studio, I think 3-phase power is 'way overkill - it costs a lot to have installed, it's more difficult to wire unless you find a QUALIFIED, and I do mean QUALIFIED, not just licenced, electrician; plus, a lot of utility companies will not even install 3-phase without a guarantee of a minimum usage of power. If you want really clean power, you should check out these guys (probably what Bryan was talking about) http://www.equitech.com/ Check out their articles and papers button, it's an education in itself... Steve

Roger that Steve! Thanks for the link too.Once again, you've been an invaluable source of good info..as has everyone else here... I better go and read those equitech papers again more thoroughly... thanks :!:

I have been looking to get one of Equi-Tech's wall mount balanced power supplies, but they are so expesive! The one I have been looking at for a while is like $6500. :shock: Can you guys perscribe any more ways besides the MOVs to clean up and filter power with a standard wall breaker box?

BTW...cool avatar Steve!! :D

Carl, how much gear (amperage-wise) were you planning on running on balanced power? (Keep in mind that your finished product, other than the improvements you'd hear while monitoring, doesn't care whether your power amps and the rest of the monitoring chain has balanced power or not - only the recording chain) - Things that can help without balanced power - surge suppressors/filters on all power distribution strips, ABSOLUTE star ground system, the lowest capacitance cabling you can find, soldered or punch block patch bays (not 1/4" jacks/plugs in the rear), keeping power runs as far away from (and non-parallel to) mic cables and line level audio, keeping digital runs (both digital audio and MIDI) at least a few inches away from mic lines, keeping "wall warts" as far away from EVERYTHING as possible - On that last, I once temporarily plugged a wall wart into the aux power plug in the rear of one of the power amps in my PA setup - the only audio cables close to it were two 18 inch long TRS balanced feeds from a Symetrics 525 compressor/expander/gate into the balanced TRS inputs of a Yamaha power amp - the cables passed within about 3-4 inches of this wall wart, and the hum was so bad I couldn't kill it with the expander/gate. All this with shielded, BALANCED, half-meter cables... Glad you liked the avatar; closest likeness to an Akita we had who died last year - smarter than most of the people I work with, and I never worried about my wife being alone nights when he was around - 150 pounds of "don't even THINK about it"... Steve

I have all the brochures for the gear so I need to sit down and calculate it out. The audio and electrical cabling is being worked out by John on the design plans. I plan to use the existing wiring for the lighting and one or two regular 15A outlet in each room for a vacuum or cellphone charger, computer, lamp, whatever. The breaker box or balanced supply would ONLY feed the outlets for audio gear and would be the AV grade outlets. The patchbays are being built pre soldered pig tails so that shouldn't be a problem. I am also considering running my OWN ground for my gear and not tapping off the building's since there is machinery being uses all over it.

Actually no Steve I was talking about something way more expensive (after installation). I figure if you got budget for 3 phase heck might as well go all out and purchase a Dry-type ISO transformer and get that puppy installed. When I was building small studios for Video production back in the Early to mid 90's We always spec'd a Dry-type Power transformer. :) I noticed that Equi=tech is now selling them as well. We always used a 10Kva unit. Really regulated the heck out of the current :) But then those Rack mount Equitech's really work well. I have one on my recording truck. when I 1st used one (which prompted my purchase) you could look at the console and see the lights (LED's) stablized. It really smoothed out the AC. And you dont need the expensive deal. Geez we go for overkill sometimes. I use the 2RQ to drive all the electronics on my remote truck.

knightfly wrote:

Things that can help without balanced power - surge suppressors/filters on all power distribution strips, ABSOLUTE star ground system, the lowest capacitance cabling you can find, soldered or punch block patch bays (not 1/4" jacks/plugs in the rear), keeping power runs as far away from (and non-parallel to) mic cables and line level audio, keeping digital runs (both digital audio and MIDI) at least a few inches away from mic lines, keeping "wall warts" as far away from EVERYTHING as possible -

Ok Steve now..with the star earthing...Are all the pieces of equipment in the studio earthed to one common point or is it just every piece on one circuit to the same ground and then again every piece on another circuit to the same ground point??

Glad you liked the avatar; closest likeness to an Akita we had who died last year - smarter than most of the people I work with, and I never worried about my wife being alone nights when he was around - 150 pounds of "don't even THINK about it"... Steve

I thought it maght have been actually your dog, and am very sorry he's not around anymore :( ..looks like a beautiful dog

Sorry..wasn't logged in again.. :x

Hey Sen. From The SAE site......

The Star Earthing System is where you ask your electrician to earth each power outlet individually (as you see in the above illustration.) In this setup each power point sees the same ground directly and a unit earthed to outlet 1 and connected with a patch lead to something earthed to outlet 2 won't see outlet 2 as it's earth because it has it's own more direct route to ground. The earth, as stated before, is connected to a copper stake in the ground.

This is a short but interesting document on tech power: http://www.soundcontrolroom.com/GuidelinesElecPower.pdf