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levyte357 View Drop Down
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    Posted: 08 July 2007 at 2:50pm
I may have this wrong, but if an amp (in UK) is powered thru a "standard" 240V socket, does this not mean the max  power the amp can supply
If the plug is fused at 13amp is:

240 * 13 = 3120W?


And if somehow the amp can be supplied with 240V @16 amps, the value is

240 * 16 = 3840W ?


Have been reading posts recently (here and other sites) about amps connected to 240v UK sockets, and having 4 or More 1850's connected, and absolutely punishing them, which according to my understanding, doesn't start happening until about 1kw per 1850.

Which in the case of 4x 1850's would mean 4k right ?
This is assuming amplifiers which are 100% efficient with "NO" loss of power through heat, leads, interconnects etc..




Edited by levyte357 - 08 July 2007 at 3:07pm
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ceharden View Drop Down
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Your calculations are correct for static current draw.  Music is not a constant load however so you can run amplifiers of a much higher rating without the average current draw exceeding 13/16A

For example:

Last night I was running a private party outdoors.  We had approx 5kW sound rig plus monitors,band backline etc.  In addition we had about 2kW of lighting if all the PAR cans were turned on at once.

The supply was one 13A socket and about 40m of cable (minimum 4mm2 because we'd jumpered up to 32A and then 63A Cee-form, the final 10m was 16mm2!)  Current wise, we didn't have any problems but  did have an issue with cumulative earth leakage (we think) taking out a 100mA RCD on the incoming supply to the house.
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That would be because 40m is outside of the protective bonding zone of the earth. A local earth spike would have sorted you out. Remove the RCD at the house, and put it on the line of the earth spike (needs a bit of thinking to wire it like that, but it's do-able)
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ive been thinking this too lev....do all amps come with a 13amp socket or are some of the larger amps fitted with ceeform jobbies? like the infinate2 mk11 for example all this talk of current draw drag races.
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levyte357 View Drop Down
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Originally posted by josh josh wrote:

ive been thinking this too lev....do all amps come with a 13amp socket or are some of the larger amps fitted with ceeform jobbies? like the infinate2 mk11 for example all this talk of current draw drag races.



Many come with some sort of 240V/16A  socket or 16amp cable with foreign mains plug. And every one mostly sticks 13amp cable/plug on it due to UK supply being a "shandy'ish" 13amp, not 16amp like on the continent.

I like the idea of only 2x drivers per amp in 4ohm bridge, so I would never have the problem of gettin enough current from each socket.

However big 8x sub gig would be 4x sockets just for 4x sub amps, unless 3 phase is in the building!

To clear this up once and for all; My sub amps will all have 16amp mains cable. If they all have 16 amp fuses, and the extension lead supplying each amp is equipped for 16Amps plus, can the amps draw upto 16A from the household mains?

As I heard the 13A limit is really regarding mains sockets, plugs.




Edited by levyte357 - 08 July 2007 at 8:07pm
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Originally posted by josh josh wrote:

ive been thinking this too lev....do all amps come with a 13amp socket or are some of the larger amps fitted with ceeform jobbies? like the infinate2 mk11 for example all this talk of current draw drag races.


The Infinite 7/8 Mk2 come with a thick cable, with some pre-tinned bare wire ends. It says in the manual it comes with a Ceeform so maybe I just got missed out, but we fitted each of ours with a Ceeform connector that goes into a little distribution board with trip switches etc. I'm no sparky so can't really tell you more than that.

Only thing is finding venues locally with enough power to really push it, without risking the ring main.


Levyte; you've got it the wrong way round, as far as I know. The socket will give you whatever you draw, it's the fuse that's the issue. If you wanna be dodgy, put a massive bit of copper wire in place of the fuse and you can pull out power as much as you like, until you go over the ring main limit and blow up the power to the building!

Edited by toastyghost - 08 July 2007 at 8:52pm
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Quote f you wanna be dodgy, put a massive bit of copper wire in place of the fuse and you can pull out power as much as you like, until you go over the ring main limit and blow up the power to the building!


Not sure if thats the kind of advice that should be given, especially when the kind of voltages your playing with are potentially lethal
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Originally posted by toastyghost toastyghost wrote:


If you wanna be dodgy, put a massive bit of copper wire in place of the fuse and you can pull out power as much as you like, until you go over the ring main limit and blow up the power to the building!
 
That is really bad advice!... You may end up with the house wiring on fire (!)
 
If you dont have enough power available in the building, you need to get a sparky to install some larger outlets and upgrade your distro
 
That said: I ran a pair of double 18s and a pair of Void Impulse 3T off a rack of Chevin amps ( A2000, 3000, 6000 and a DSP ) off a single phase 16A feed with no problems some weeks ago...
 
/peter
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levyte357 View Drop Down
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Originally posted by Rockin Rockin wrote:



Not sure if thats the kind of advice that should be given, especially when the kind of voltages your playing with are potentially lethal



Anyone else using these to get 100% safe 16amp from household socket?





Edited by levyte357 - 08 July 2007 at 11:54pm
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You cannot draw more than 13amps from a UK domestic plug safely.
 
I don't understand the above device. It looks like it has a transformer of some description, which doesn't make sense because to up the current, you need to decrease the voltage.
 
Now my maths isn't too hot without a figures table infront of me, but you would need to drop the voltage to around 200v - 205v to get 16amps.
 
Where did you get that picture Lev?
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levyte357 View Drop Down
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Originally posted by Ben_Lawrance Ben_Lawrance wrote:

You cannot draw more than 13amps from a UK domestic plug safely.
 
I don't understand the above device. It looks like it has a transformer of some description, which doesn't make sense because to up the current, you need to decrease the voltage.
 
Now my maths isn't too hot without a figures table infront of me, but you would need to drop the voltage to around 200v - 205v to get 16amps.
 
Where did you get that picture Lev?


http://cgi.ebay.co.uk/240v-SITE-RATED-RCD-16amp_W0QQitemZ280121359025QQihZ018QQcategoryZ26215QQtcZphotoQQcmdZViewItem

Maybe it's just RCD Protection +  some Huge capacitors ?


Edited by levyte357 - 09 July 2007 at 12:20am
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ceharden View Drop Down
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Just because it has a 16A outlet, doesn't mean there is 16A available!

It should probably have a 16A Ceeform inlet too if it's really for site use.

It's probably just an RCD in a big box you can't break/loose etc.  I doubt it does any more than the ones you get built into a 13A socket.
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