Neutral Q

[Alwayslearningelec]

This feeder with 3 #1/0 and G is obviously wrong as it needs the neutral, because it's 3Phase 4W panel and 3 P breaker correct?

 

[retirede]

A neutral isn’t required if there are no L-N loads.

 

[infinity]

because it's 3Phase 4W panel and 3 P breaker correct?

Nothing on that drawing indicates that a neutral is required. #1/0 for 300 amps is incorrect.

 

[Alwayslearningelec]

Here's the remainder of loads/one line.. MDP and LP panels. There's has to be L to N loads..lol.

And if your feeding a 3P 4W panel you'd need the neutral. Feed to LP has no neutral.

 

[Alwayslearningelec]

Nothing on that drawing indicates that a neutral is required. #1/0 for 300 amps is incorrect.

2 sets of 1/0.

 

[don_resqcapt19]

Here's the remainder of loads/one line.. MDP and LP panels. There's has to be L to N loads..lol.

And if your feeding a 3P 4W panel you'd need the neutral. Feed to LP has no neutral.

You only need to install a neutral if that panel has line to neutral loads. A 3P 4W panel does not require a neutral if there are no line to neutral loads.

 

[Alwayslearningelec]

You only need to install a neutral if that panel has line to neutral loads. A 3P 4W panel does not require a neutral if there are no line to neutral loads.

Thanks. How do know if a load is line to neutral?

 

[infinity]

Is the feeder in post #1 feeding a 1Ø, feeder? If so then the neutral is there.

 

[Alwayslearningelec]

Is the feeder in post #1 feeding a 1Ø, feeder? If so then the neutral is there.

Don't understand what your asking. The continuation is in post #4.

 

[infinity]

The continuation is in post #4.

So this is panel LP-1? Is there a tap in what appears to be a wireway?

 

[don_resqcapt19]

Thanks. How do know if a load is line to neutral?

Are there any single pole breakers?

 

[ggunn]

Here's the remainder of loads/one line.. MDP and LP panels. There's has to be L to N loads..lol.

And if your feeding a 3P 4W panel you'd need the neutral. Feed to LP has no neutral.


View attachment 2575847

View attachment 2575846

How are you getting 120/240V single phase in the Power Riser Diagram from a 208/120V three phase service?

 

[infinity]

How are you getting 120/240V single phase in the Power Riser Diagram from a 208/120V three phase service?

He's not. The distribution panel (MCP) shows single phase, 120/208 volt panels.

 

[LarryFine]

Thanks. How do know if a load is line to neutral?

Single-pole breaker, or a 2- or 3-pole breaker feeding a load with a neutral conductor.

If you have any one or more of these, you need a neutral in the feeder.

 

[gadfly56]

Are there any single pole breakers?

There appear to be, at the very bottom, (4) 1-pole breakers.

 

[retirede]

This certainly would have been easier to address if the first post contained all relevant information!

 

[Alwayslearningelec]

This certainly would have been easier to address if the first post contained all relevant information!

Sorry. Yellow are new circuits. So below is the one line, panel MDP( which feds sub panels) and one sub panel schedule.

1. The heat trace circuits out of LP-1 have to be line to neutral correct?
2. Also looks like loads out of sun panel 1A are line to neutral?

 

[infinity]

Yes the 2 sets of (3)-#1/0 is incorrect. That parallel feeder requires a neutral. The (3)-#6 to LP-1 is wrong becuase that requires neutral also.

 

[ggunn]

He's not. The distribution panel (MCP) shows single phase, 120/208 volt panels.

On the Power Riser Diagram it shows "MDP1 250AMP 120/208Y 3 PHASE MAIN BREAKER" feeding "2C SUB PANEL 120/240 1 PHASE MAIN LUG". Does that just mean the panel is 240V rated but the circuits will all be 208/120V single phase?

 

[infinity]

Does that just mean the panel is 240V rated but the circuits will all be 208/120V single phase?

Yes it will be supplied by 120/208. I'm guessing that the panel is rated for 120/240 as you've stated.