4 x XPA amplifiers power on main

[giubio]

Assuming I have four amplifiers and one pre:
n. 1 pre RMC-1
n. 2 ampli XPA-DR2
n. 2 ampli XPA-5
all them supplìed at 230 Vac (the italian voltage)
wich will be the current (in Amperes) needed in the main?
My home has the main capable of 6 kW continuous at 230 Vac and the protection is set at 12 Amperes 

[leonski]

Right off the top before any calculations, I'd say you have insufficient power from a single outlet.

12 amps @230volts (What is the Real, Measured voltage?) is just over 2.7kw, or about half the service to your house..

Even my modest (by US standards) house built over 30 years ago has a 100amp service. That's 24kw, about, at an input

voltage of 240. I don't know the real value.

But the amplifiers you have? The XPA-DR2 are EACH over 1kw output. The XPA-5 G2 EACH have a 1200va transformer.

The Powersupply claim for the DR3 is 'over 3kw output'......


Do you NEED such a huge amount of power? I presume some large space, maybe 600 cubic meters?

Here in the STATES, you'd have roughly the same capacity as 2x of our '15 amp' circuits @117 volts.


Now for some questions? How LOUD do you like it? How SENSITIVE are your speakers? How large the room in CUBIC measure?

Any chance of getting a 2nd circuit to the HT setup? DO NOT believe those 'efficiency' claims. It is nonsense. Just keep in mind

that from your wall outlet TO your ears, even the highest rated system will be No Higher than maybe 5% efficient. Speakers are HORRIBLE

while A/B amp outputs are maybe 50% when run at the 'best' value.....which is RARELY. You're more likely to see in-use amp efficiencies

about 1/2 that.

[giubio]

The amplifiers are able to erogate the power of 3kW, but they do not charge the main for the same power.
The real amount of power needed depends on the volume adjustment, that, of of course, will never be more than 25 to 50%.
Also, the peaks of power needed are just...peaks, not continuous, so I presume the power needed for a normal listening session can not require more than (4 x 3kW) * 30% = 3.6kw and the contract of my utility is for 6 kW (in Italy 6kW this is the maximum for home).
Of course one outlet is not enough. I am preparing the layout of the circuit with at least 6 outlets with wiring of 4 mms

I think the entire system, at normal listening volume, will be not more than 3 o 4 kW, not continuous with peaks of 5 o 6 for less than a pair of seconds.
The intervention of the protection (12A, or 24kW peak power) is delayed by minimum 10 seconds, warm to cold pole, and 0.1 sec for warm pole to ground for safety.
This is my personal opinion, but, I would like to know from te people in this forum which is the real consumption for normal listening for the DR2 or the XPA-5 at 110Vac.
With 230/240Vac the Amperes will be the half.

[leonski]

Nov 22, 2020 19:28:02 GMT -5 giubio said:

The amplifiers are able to erogate the power of 3kW, but they do not charge the main for the same power.
The real amount of power needed depends on the volume adjustment, that, of of course, will never be more than 25 to 50%.
Also, the peaks of power needed are just...peaks, not continuous, so I presume the power needed for a normal listening session can not require more than (4 x 3kW) * 30% = 3.6kw and the contract of my utility is for 6 kW (in Italy 6kW this is the maximum for home).
Of course one outlet is not enough. I am preparing the layout of the circuit with at least 6 outlets with wiring of 4 mms

I think the entire system, at normal listening volume, will be not more than 3 o 4 kW, not continuous with peaks of 5 o 6 for less than a pair of seconds.
The intervention of the protection (12A, or 24kW peak power) is delayed by minimum 10 seconds, warm to cold pole, and 0.1 sec for warm pole to ground for safety.
This is my personal opinion, but, I would like to know from te people in this forum which is the real consumption for normal listening for the DR2 or the XPA-5 at 110Vac.
With 230/240Vac the Amperes will be the half.

EXACTLY:   so why the heck do you NEED so much power if you never USE IT?   
Peak to continuous is Typically taken as 10db or 10x the power.    So?   If your amps are producing a total of 100 watts?   A 10db peak is a full KW.   Given a reasonable number for efficiency of the amplifier, you can
work backwards to your line.    In NO CASE will the total efficiency of such a system exceed maybe 5%.    That's how much acoustic power is produced VS power consumed from your utility.  

IMO, your estimate is Way High for continuous power.   Again, speaker sensitivity needs to be known as are listening habits.    

Keep in mind that even middle of the road sensitive speaker will put you OUT of the room at 10 watts.   An entire system?    It's gonna get LOUD.    

Chances are, with your plan you should be OK.    Multiple outlets on independent circuits are a very good idea.   You are saying that PEAK is 10X Continuous?   12A@240V is 'only' 2.88kw.....
Is my math in error?  
Here in the states we express it somewhat differently.    A 20 amp circuit is 2.4kw Short Term with a 20% derate for longer time periods.    I don't know the limits.  

I just read thru your post again.   3 to 4 KW 'at normal listening volume' is a HUGE number.   I would guess a far lower number, unless you have measured data.   +

You still have NOT answered the question of speaker sensitivity.    That's going to be in DB per watt at one meter.    1 watt is 2.83 volts at 8 ohms.   2 volts @4ohms, but never measured that way.  

4mm wire??   In the USA that would be an unheard of 6 gauge......10 gauge is most frequently used LARGE wire while 12 is what you will find on 20 amp circuits.   I don't know that a standard breaker will accommodate 6 gauge.

Except for the fact I'm not into all that excess power, I think you are on-track with the multiple outlet idea.    I personally have 1x20 amp circuit for JUST my amplifiers.    A 2nd circuit is a shared circuit for the Television
and small draw stuff.    I have a very good power conditioner which has a 400va isolation transformer which I use for the low power stereo and television stuff.  

I just went outside for a look.   My main panel breaker is 100amps and I have 2x120 legs which I can 'Y' for 240 volts service like for certain appliances.   

[leonski]

Have you spoken with an electrician? He can address continuous V intermittent draw and may have some idea of your total draw. I don't know how that is rated in Europe. Here? We have a 20% 'derate' from maximum....