[Amps] what is a 4 wire 240VAC service?

[Jim Brown]

On 4/4/2011 3:49 AM, Jim Thomson wrote:
> &&   I read 2 x yrs ago, there is a new standard in the Pro audio industry..called ... `balanced power`     They ended up  with 60 vac  from each hot side to neutral.   It was recognized by the power co`s too..and has it`s own sub section
> in the electrical code.   You can get the same result by running the same audio gear on 240 vac to begin with....if it`s capable of 240 vac operation.

While this practice DOES exist, and a sub-section was added to NEC to 
allow it with severe restrictions on HOW it can be used, it is used only 
a few fools who don't understand the laws of physics. It offers 
virtually no real benefit, and is far more costly than other practices 
that do far more to minimize hum, buzz, and RFI. The sub-section was 
added to NEC after intense lobbying from one or more companies who had 
equipment to sell, and by rock and roll roadie types who didn't 
understand the fundamental physics.

It is NOT a standard, nor are there any AES (Audio Engineering Society) 
Standards that suggest or condone it.

73, Jim K9YC
Vice-Chair, AES Standards Committee Working Group on EMC