use of proper equations and voltage values - 3 phase or single phase

[Smart $]

Thank you so much for explaining
but it is a bit confusing
you have two voltage values 208/120 and the formula doesnt tell which one to use
they just tell you use "E" but which one ????
so it depends on that particular circuit and what is on it
also when it comes to the three phase formula you dont always use it even though the voltage is 3 phase
again it depends on what is on that particular circuit

Regarding common U.S. 3? alternating current systems, a few things to remember to make it less confusing:

A 2-wire circuit is always 1?
Note number of circuit wires disregards any Equipment Grounding Conductor (EGC).

If one wire is connected Line (L, or more specifically L₁, L₂, or L₃) and one to Neutral (N), it is the lower voltage.

If both are connected to L, then it is the higher voltage.

A 3-wire circuit is 3? if each is connected to a different Line. If one of the three is connected to Neutral, it may be split-phase 1? (e.g. 120/240 on a 240/120V 3? 4W system), or have 3? current implications, but considered 1? circuits (e.g. 120/208 on a 208Y/120V 3? 4W system).

When you understand 3? 4W voltage systems, you will understand 4-wire circuits (...'cause I'm getting lazy ).

 

[Smart $]

Regarding common U.S. 3? alternating current systems, ...

PS: L₁, L₂, and L₃ are commonly denoted as A, B, and C, respectively.

 

[K8MHZ]

You would not want a receptacle that provides 277V to look just like one that is connected to 120V! You don't want be able to plug in a 120V appliance to a 277V source.

See 406.3 (F) about that, but also be advised that there are such things as 277 volt receptacles. Check out NEMA 7-15 through 7-50 types.

Just for example, Hubbell P/N HBL5302

 

[ZMIKE123]

THANKS AGAIN

THANKS AGAIN

wow !!!!!!!!!!!
i learned alot just today
thank you all so much for your help
i can see you guys really know your stuff here
ITS A PRIVILIGE AND PLEASURE TO BE HERE
thanks again