Haligan;
The best and simplest answer I can give or explain to you for:
"What Are Non-Line-To-Noodle (Neutral / Grounded Conductor) Loads"Would be this:
"Any Circuit / Load Which Does Not Use The Grounded System Conductor"
L-L (Line-to-Line) and / or 3Ø L-L-L (Line-to-Line-to-Line) Circuits + Connections to Equipment do not use a Grounded Conductor for their Circuitry.
Most commonly known types of these loads would be 1Ø Air Conditioners, Electric Water Heaters and 3Ø Induction Motors.
These loads would have Branch Circuits deriving from 2 or 3 Pole Circuit Breakers.
As already mentioned, the "Typical" L-L Voltages (U.S. Systems) would be:
208, 230 (240), 460 (480) and 575 (600).
This is not 100% default though, as a "Single Voltage" rated system - and even a Multiwire type System, may have these voltages between an Ungrounded Conductor and a Grounded Conductor.
The key on the "Single Voltage" rated systems is the Grounded Conductor is not the typical "Noodle" (Neutral / Common Conductor).
For a 3Ø 3 Wire Grounded Delta, there is a Grounded Conductor, but it's not a "Neutral".
The Voltage between any two conductors will be (close to) the same no matter which 2 Lines are measured.
For instance, if the system was 240 VAC, there will be 240 VAC between any two wires - even the one which is Grounded and any of the remaining two Ungrounded Conductors.
Voltage to Ground will be 240 Volts from any of the two Ungrounded Conductors, and ZERO from the Grounded Conductor and Ground.
An example: If we Grounded Ø Line "C" at the Transformer + the Service, ØA and ØB will show 240 VAC to Ground, but ØC will show ZERO Volts to Ground.
Measuring between A-B, B-C or A-C will show 240 VAC.
The exception to the L-N / L-L reading would be what's found on the 120/240V 3Ø 4 Wire Delta.
The system will have a nominal L-L Voltage of 240 VAC from A-B, B-C and A-C.
The winding forming "A-C" at the Transformer, is Center Tapped - which results in a Voltage of 120 VAC from Line A and Line C to the Center Tapped Grounded Neutral Conductor / Ground.
From Line B, the Voltage to the Center Tapped Grounded Neutral Conductor / Ground is around 208 VAC.
There are a lot more varieties of systems which differ greatly from "The Common Ones", which may be discussed in detail if needed.
Check out the Electrical Theory and Applications area for past threads covering these items. Also check through the Technical Reference section for various Scematics of Transformers + etc.
Bob (Iwire) has done very well with the information He has posted in this thread!
Allright Bob!!!
To try and assist a bit on the "+/-" and "Returning Current" subjects of AC, refer to the Transformer Schematics shown in one of Bob's (Iwire) posts.
First thing - do not even worry about anything being Grounded! Consider all these Transformers to have absolutely no physical connection to "Ground" at any point.
The Inputs (Primaries) and Outputs (Secondaries) will not be Physically Connected To the Earth Ground anywhere.
This eliminates the "Ground Return" consept all together - and helps make the most important points about the normal operation of an AC Power System.
With the above stuff in mind, visualize the Current Flow on each side of the Transformer - Primary Windings and Secondary Windings.
Visualize the Current flowing acrossed each Winding as if it was moving like the Blade of a Sawzall (Reciprocating Saw).
Picture it going back and forth, keeping a constant "Frequency" time speed, yet "Peaking" at the "End" of a certain direction's movement (as the Blade reverses direction and moves the other way).
Picture this continuing over and over and over - like two Kids on a "See-Saw", when one Kid goes up, the other goes down. The Kid that went down pushes up off the ground, causing the "Up" Kid to come down, reversing the directions of movement for the two Kids.
If they don't get tired (or bored), they will continue to "Alternate" their positions between "Up" and "Down" - yet they are still the same Kids, on the same Teetering Board, with the same Fulcrum Point at the Center of this "Lever" - the Teetering Board.
That is what simply is going on with the Current on an AC Circuit - the Current 'Runs" in one direction, then "Runs" in the other direction.
There is no fixed Polarity (only "Transient Polarity Points or Reference Points) - just like the Sawzall Blade and the Kids on the See-Saw.
This simple theory may be applied to any of the Transformer Schematics shown in this thread, and to any of the Windings (Primary or Secondary) - regardless if there's 2 or 3 wires from the coil.
It's that simple!!!
For more information, check the Electrical Theory / Applications section, and the Technical References section here at ECN.
Also feel free to ask any additional questions you may have.
Scott35