Reply to thread

Message

<blockquote data-quote="TJ Cornish" data-source="post: 115597" data-attributes="member: 162">Re: X32 v2 RTANote - I got distracted/delayed in the middle of typing this, and others have covered some of the ground here already.&nbsp; Mac is correct, though confusion in this arena is somewhat understandable, since terminology and scope are confusing.Power is generated in 3 phases, and in broad strokes, is distributed around the country in 3 phases.&nbsp; At some point, mostly in residential and light commercial areas, the 3 phase branch circuit is split around the neighborhood, with the last mile transformers operating off one of the supply phases on the primary side; the secondary side is a center-tapped winding, creating two hot legs 180° out of phase and/or polarity (interchangable in this particular case).&nbsp; Whether you call this single phase or two-phase is mostly a matter of semantics and convention.&nbsp; It&#039;s definitely single-phase-derived, however the result is definitely two-phase as seen on an oscilloscope.&nbsp; Once again, there&#039;s more similarity than difference between true 3-phase power and &quot;two-phase&quot; power, as by the time you and I see it, we are seeing the result of multiple transformers, and whether we have 3 legs 120° apart or 2 legs 180° apart doesn&#039;t make a lot of difference to single-phase loads (single-phase in this context being defined as devices requiring one hot and one neutral).All of that is fairly academic.&nbsp; The kicker here is &quot;does it make any difference whether things are supplied from the same phase or not?&quot;&nbsp; The answer is:&nbsp; ~~Drumroll please~~ generally not much.&nbsp; Even loads separated on different &quot;phases&quot; share the same neutral wire and ground wire if they are fed from the same transformer, so they are really not that separate.&nbsp; To get true separation, you need multiple services derived from multiple transformers, with complicated ground scenarios, and even then you can still get goofed up with induced noise from wires in proximity to other wires and/or noise sources.I haven&#039;t read the thread and haven&#039;t followed the situation at hand, but the short answer is that no, it&#039;s not generally recommended to separate lighting and audio on different phases.&nbsp; It&#039;s generally better to balance the load on all phases, which reduces neutral current and stress on the infrastructure from phase imbalnces, and to deal with noise issues other ways.</blockquote>

[QUOTE="TJ Cornish, post: 115597, member: 162"] Re: X32 v2 RTA [B] Note - I got distracted/delayed in the middle of typing this, and others have covered some of the ground here already. [/B] Mac is correct, though confusion in this arena is somewhat understandable, since terminology and scope are confusing. Power is generated in 3 phases, and in broad strokes, is distributed around the country in 3 phases. At some point, mostly in residential and light commercial areas, the 3 phase branch circuit is split around the neighborhood, with the last mile transformers operating off one of the supply phases on the primary side; the secondary side is a center-tapped winding, creating two hot legs 180° out of phase and/or polarity (interchangable in this particular case). Whether you call this single phase or two-phase is mostly a matter of semantics and convention. It's definitely single-phase-derived, however the result is definitely two-phase as seen on an oscilloscope. Once again, there's more similarity than difference between true 3-phase power and "two-phase" power, as by the time you and I see it, we are seeing the result of multiple transformers, and whether we have 3 legs 120° apart or 2 legs 180° apart doesn't make a lot of difference to single-phase loads (single-phase in this context being defined as devices requiring one hot and one neutral). All of that is fairly academic. The kicker here is "does it make any difference whether things are supplied from the same phase or not?" The answer is: ~~Drumroll please~~ generally not much. Even loads separated on different "phases" share the same neutral wire and ground wire if they are fed from the same transformer, so they are really not that separate. To get true separation, you need multiple services derived from multiple transformers, with complicated ground scenarios, and even then you can still get goofed up with induced noise from wires in proximity to other wires and/or noise sources. I haven't read the thread and haven't followed the situation at hand, but the short answer is that no, it's not generally recommended to separate lighting and audio on different phases. It's generally better to balance the load on all phases, which reduces neutral current and stress on the infrastructure from phase imbalnces, and to deal with noise issues other ways. [/QUOTE]

Verification