Neutral NOT as CCC

[xformer]

Can someone give me a few practical examples of when 310.15B5a would be used?

 

[jumper]

Any MWBC. Except 3 phase MWBCs with high harmonics, over loaded with computers, fluorescent lights and such.

 

[jumper]

I did not mean to include 2 phase circuits off 3 phase, but I did not state that when I said "any".:slaphead:

 

[jumper]

This is an excerpt from another member(Infinity/Rob) that I keep handy:

Here's some examples of when to count the neutral as a CCC:

208Y/120 volt system-different circuit types:

A)- 2 wire circuit w/ 1 ungrounded, 1 neutral = 2 CCC's
B)- 3 wire circuit w/ 2 ungrounded, 1 neutral = 3 CCC's
C)- 4 wire circuit w/ 3 ungrounded, 1 neutral = 3 CCC's*

Notes:
A)- A normal 2 wire circuit has equal current flowing in each of the circuit conductors so they both count as CCC's.
B)- In this circuit the neutral current will be nearly equal to the current in the ungrounded conductors so the neutral counts as a CCC
C)- In this circuit the neutral will only carry the imbalance of the current between the three ungrounded conductors so it is not counted as a CCC, with one exception, *if the current is more than 50% nonlinear then the neutral would count as a CCC.

120/240 volt system-different circuit types:

D)- 2 wire circuit w/ 1 ungrounded, 1 neutral = 2 CCC's
E)- 3 wire circuit w/ 2 ungrounded, 1 neutral = 2 CCC's

Notes:
D)- A normal 2 wire circuit has equal current flowing in each of the circuit conductors so they both count as CCC's.
E)- In this circuit the neutral will only carry the imbalance between the two ungrounded condcutors so the neutral is not counted as a CCC.

 

[Dennis Alwon]

When you have a full house in either single phase or 3 phase the neutral often doesn't count unless most of the load is non linear-- high harmonic as in computer or electronic equipment- fluorescent lights, etc.

 

[jumper]

When you have a full house in either single phase or 3 phase the neutral often doesn't count unless most of the load is non linear-- high harmonic as in computer or electronic equipment- fluorescent lights, etc.

Dennis, it is a "full boat" not "house.":lol:

Playing a lot of cards are we?

 

[Dennis Alwon]

Dennis, it is a "full boat" not "house.":lol:

Playing a lot of cards are we?

Yep- a freudian slip or as my brother Floyd would say "Floydian Slip"

 

[jumper]

Yep- a freudian slip or as my brother Floyd would say "Floydian Slip"

LMAO

 

[RUWired]

This is an excerpt from another member(Infinity/Rob) that I keep handy:

Here's some examples of when to count the neutral as a CCC:

208Y/120 volt system-different circuit types:

A)- 2 wire circuit w/ 1 ungrounded, 1 neutral = 2 CCC's
B)- 3 wire circuit w/ 2 ungrounded, 1 neutral = 3 CCC's
C)- 4 wire circuit w/ 3 ungrounded, 1 neutral = 3 CCC's*

Notes:
A)- A normal 2 wire circuit has equal current flowing in each of the circuit conductors so they both count as CCC's.
B)- In this circuit the neutral current will be nearly equal to the current in the ungrounded conductors so the neutral counts as a CCC
C)- In this circuit the neutral will only carry the imbalance of the current between the three ungrounded conductors so it is not counted as a CCC, with one exception, *if the current is more than 50% nonlinear then the neutral would count as a CCC.

120/240 volt system-different circuit types:

D)- 2 wire circuit w/ 1 ungrounded, 1 neutral = 2 CCC's
E)- 3 wire circuit w/ 2 ungrounded, 1 neutral = 2 CCC's

Notes:
D)- A normal 2 wire circuit has equal current flowing in each of the circuit conductors so they both count as CCC's.
E)- In this circuit the neutral will only carry the imbalance between the two ungrounded condcutors so the neutral is not counted as a CCC.

Attached is a visual aid to go along with the post.

View attachment Counting CCC.sdr.doc

 

[jumper]

Attached is a visual aid to go along with the post.

View attachment 6838

Nice. Saved that.:thumbsup: