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

[Sen]

Hello all,
I thought I would post this inquiery here hoping that someone could help.
A warning first 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!

[Aaronw]

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

[giles117]

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

[Sen]

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

[giles117]

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.

[giles117]

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.

[Guest]

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

[Sen]

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

[knightfly]

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

[Sen]

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)
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

[Aaronw]

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

Yep.

[knightfly]

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

[giles117]

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.

[Sen]

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
cheers

[knightfly]

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