This Is Not An Exam Question!!

[kuiperbelt]

Neighbour and his Dad possess 2 x 2500 Watt loudspeakers
with built in Amplifiers. He believes on max output they would draw
nearly 20 Amps each. He is afraid this will trip the 32Amp ring breaker.
Someone please advise.

[Hymie]

As their neighbour, you must me hopping that it causes the main incoming fuse in the consumer unit to blow.

[Hymie]

If they are each drawing in excess of 13A they will require connection to the mains supply by other than a BS 1363 (13A) mains plug – normally an IEC 60309 plug and socket arrangement.

[klazomaniac]

Hymie is correct regarding BS1363 type cartridge fuses.

Below is a 2500W (built in amp) speaker. If you scroll to the specs, You'll see that it only consumes 1100W

Therefore: P / V = 1100W / 230V = 4.78 A

I am not an electronics expert, But I would hazard a guess that the consumption of the setup would be approx the same. So with both functioning at full capacity, You would be looking at a draw in Current of about 10A max.

Get some earplugs kuiperbelt ;-)

[klazomaniac]

https://www.gear4music.com/PA-DJ-and-Lighting/Alto-Professional-TS412-2500-Watt-Active-PA-Speaker/52XA

[The Builder]

If I remember correctly, amplifiers are often quoted with a 'Peak power' output.
A sort of maximum power that can be generated (theoretically) for a fraction of a second.
What you actually hear is RMS (Root Mean Square) which is a little less than half Peak power.

[ZebuSanctuary]

On the proviso these are 240 volt active loudspeakers as opposed to being passive, the liklihood, 2500 Watts is the peak power rating.

However, let us look at the instance where the continuous power rating (rms) of the loudspeaker is 2500 Watts.

Assuming 8Ω impedance, current flowing through the speaker coil √(2500/8) approximates to 18 Amps. Add on another 2 to 3 Amps for ancillary circuitry, then rounding up, we arive at 20 Amps (your neighbour's reckoning). Doubling up gives 40 Amps for the two speakers.

It must be remembered this is the current derived from the the secondary circuit of a mains transformer. It would not be unreasonable to suggest a 2:1 step down mains transformer in each active loudspeaker. This results in 10 Amps flowing in the mains fed primary circuit of each transformer.

Therefore the 32Amp breaker on the ring main (handling 20 Amps) will comfortably operate without tripping. Conventional 13Amp plug more than adequate.