Why can't i find a 32 amp version of this?

Adam_Iron_Horse wrote: He's just bought a distro so he can take advantage of this feed, but I had it in my mind we would have to try and distribute the power across the 3 phases. Should we be worried about this or would be ok to take a 32A feed for the amp rack and then lights off another phase. (The hall really isn't large enough to warrant a 63A phase I wouldn't say only a 300 person limit) Cheers

If you are on the national grid then don't worry too much about phase balancing, the only thing to watch out for is your neutral current. Due to the way we wire electrical systems the CSA of the wire for the neutral will only be the same CSA as a phase, yet due to harmonics the current you potentially could be putting down the neutral wire can, in certain situations, be higher than the current you are pulling from any one phase. This can lead to an overloaded neutral, and in old installations where you don't have a 4 pole breaker (or any over current breaker on the neutral) this can lead to problems. In your case as you will be drawing less than 32a per phase (depending on how much lighting you have, but certainly less than 32a on your feed for audio) from a 63a feed, the neutral will definitely be oversized enough not to worry about it.

Don't forget that if only one supply in a 300 people hall that lighting can very quickly fill that 63a supply, and want more. It's not just about the audio

Edit - Spelling


Edited by James Tengo - 09 April 2013 at 10:54am

James Tengo wrote: Adam_Iron_Horse wrote: He's just bought a distro so he can take advantage of this feed, but I had it in my mind we would have to try and distribute the power across the 3 phases. Should we be worried about this or would be ok to take a 32A feed for the amp rack and then lights off another phase. (The hall really isn't large enough to warrant a 63A phase I wouldn't say only a 300 person limit) Cheers If you are on the national grid then don't worry too much about phase balancing, the only thing to watch out for is your neutral current. Due to the way we wire electrical systems the CSA of the wire for the neutral will only be the same CSA as a phase, yet due to harmonics the current you potentially could be putting down the neutral wire can, in certain situations, be higher than the current you are pulling from any one phase. This can lead to an overloaded neutral, and in old installations where you don't have a 4 pole breaker (or any over current breaker on the neutral) this can lead to problems. In your case as you will be drawing less than 32a per phase (depending on how much lighting you have, but certainly less than 32a on your feed for audio) from a 63a feed, the neutral will definitely be oversized enough not to worry about it. Don't forget that if only one supply in a 300 people hall that lighting can very quickly fill that 63a supply, and want more. It's not just about the audio Edit - Spelling