Commercial circuit loading question...

[benny]

Hi,

I work for a company who supply pa systems for commercial sites, sometimes these are 5 or 6 large racks.

We supply them with a flying lead, and thats where we leave it.

On the last system we supplied there was 6 racks that had a total load of 10.5 kW's. evenly distributed.

Can a client plug these into the same ring without a problem? (I'm just interested, we usually supply them to companies that are running all the cabling anyway but I've never asked how they do it).

Thanks,

 

[electronicsuk]

10.5kw @ 230v is around 45 Amps, so no, this load would be too high for a standard 32A ring.

What do you base your 10.5kW figure on? I ask because you mention PA systems (no doubt these racks contain amps), and the output power at the speaker terminals of an amplifier is not the same as the current drawn by the power supply.

 

[benny]

Thanks Mathew,

I based the calcs on the draw from the equipment, it includes quite a few power supplies and battery chargers (its all battery backed up 24 volt gear).

Kev

 

[RF Lighting]

10.5kW does not sound like an unreasonable figure for a commercial PA system.

My mate works in a large theatre, and they regulally have touring companies turning up with an audio rig requiring a 32A three phase supply.

 

[breezer]

ouch

 

[JohnD]

The theatre I used to work at had switchable power packs, so you could configure them to be 3-phase or SP.

At the time I think I put them on a C20 radials off a submain to the gallery (at switch-on they sometime tripped Bs)

 

[electronicsuk]

10.5kW does not sound like an unreasonable figure for a commercial PA system.

My mate works in a large theatre, and they regulally have touring companies turning up with an audio rig requiring a 32A three phase supply.

Agreed, although I own some PA gear myself and am also an active member of some other discussion boards related to the sound/light industry and have often seen people make the assumption that 3kw amp = 3kw drawn on the mains side. Just thought it was worth pointing out

 

[RF Lighting]

Agreed, although I own some PA gear myself and am also an active member of some other discussion boards related to the sound/light industry

Yeah me too

Blueroom?


For the benifit of others, I have a 500W (output) power amp which requires a 420W electrical supply

A 2kW amp needs a 1.3kW electrical supply (well the one I'm looking at does). A few of these can soon add up.

 

[electronicsuk]

Yeah me too

Blueroom?

Damn, my secret lare is no longer a secret!

 

[Spark123]

Yeah, I'm on there too sometimes, so I take it you are the very same electronicsuk that I gave an earbending about widowmakers? I use the username pauldf over there btw.

 

[electronicsuk]

Yeah, I'm on there too sometimes, so I take it you are the very same electronicsuk that I gave an earbending about widowmakers? I use the username pauldf over there btw.

No, doesn't ring a bell. My username over on the BR is the same as here though.

 

[davelx]

and I'm on there too. but different use name.