Incorrectly added neutral ?

[dm9289]

I have a situation where a 4th wire (neutral) was added to a disconnect ( 3hots and ground input 3hots and ground and neutral output ground and neutral hooked to case) and i believe improperly??? Input appreciated????. There are currently no line to neutral loads but i think this could be a future problem. Also in this hand made diagram there are other overcurrent protection problems but I would like to concentrate on the neutral for now.

Thankyou you guys are a great help to my education

Dave

 

[LarryFine]

I agree. It's at best a redundant EGC.

To be a neutral, it would have to have a direct connection to a secondary neutral.

 

[dm9289]

I agree. It's at best a redundant EGC.

To be a neutral, it would have to have a direct connection to a secondary neutral.

Thank you for taking time to look at my crappy diagram. Btw that 400amp disco is fed by a cable 3 hits bare stranded ground

 

[augie47]

You are correct. The neutral conductor should be eliminated or made a redundant EGC
Might be worth varifying that the gear is properly rated and not just rated for a 480/27 system.

 

[dm9289]

You are correct. The neutral conductor should be eliminated or made a redundant EGC
Might be worth varifying that the gear is properly rated and not just rated for a 480/27 system.

Thank you for your expertise and experience

 

[dm9289]

I agree. It's at best a redundant EGC.

To be a neutral, it would have to have a direct connection to a secondary neutral.

Thank you for your time this started as a tech in training installing an outlet for a monitor, he had some questions and the more I looked the worse things were. I omitted. several bad things with this install to concentrate on the neutral.

 

[dm9289]

You are correct. The neutral conductor should be eliminated or made a redundant EGC
Might be worth varifying that the gear is properly rated and not just rated for a 480/27 system.

I am going to be buying a new 480 panel cause the current one has no main and shares the tapped feed with a transformer. 125amp main lug panel fed from 400amp breaker not desired.
Since there is currently no neutral loads is there a special Panel i buy or just do not hook up neutral?


Working in that gear and pulling a new wire or cable is possible if the plant shuts down which we do not want to do. I would like the idea of having the neutral available but at this time its not necessary. There appears to be a few safety issues that need to be resolved.

 

[augie47]

If it is a 480 ungrounded or corner grounded system you need to make sure the panel is rated for that system.
There are panels on the market designed for 480/277 systems that, even thought they have a "480 rating", they are not suitable for 480 ungrounded or corner grounded systems
(Se 240.85 for additional information)

 

[Tulsa Electrician]

Be sure to relabel that 480 volt panel once the netutal wire has been removed or changed. Surprised there is no main in the 120/240 panel after the transformer and no OCD in 480 volt only panel after tap.
Got your work cut out for ya.

I see the main switch gear is 480 three phase ?? Three or four wire .
grounded or ungrounded.
What type of system? You may other issues.

 

[Tulsa Electrician]

If it is a 480 ungrounded or corner grounded system you need to make sure the panel is rated for that system.
There are panels on the market designed for 480/277 systems that, even thought they have a "480 rating", they are not suitable for 480 ungrounded or corner grounded systems
(Se 240.85 for additional information)

You must have posted why I typed.
He said plant I would be it's a 480 volt corner grounded delta. Just a quess

 

[dm9289]

Be sure to relabel that 480 volt panel once the netutal wire has been removed or changed. Surprised there is no main in the 120/240 panel after the transformer and no OCD in 480 volt only panel after tap.
Got your work cut out for ya.

I see the main switch gear is 480 three phase ?? Three or four wire .
grounded or ungrounded.
What type of system? You may other issues.

It is a 480volt wye I cant open the busway or gear to verify 3 or 4 wire (Arc flash policies) but I suspect 4. I have been digging around I think i have a Picture with the utility transformer open.

This single outlet job is the gift that keeps on giving. The 400 amp feed is 4/0 230amp plus 60ft away its tapped to a number #10 for a transformer. It goes on and on. I think at one point this portion of mill was knocked down due to a wind storm.

 

[Tulsa Electrician]

I was just about to edit. I seen gfpe in drawing.
Look for a drawing tag on trans.

 

[dm9289]

I was just about to edit. I seen gfpe in drawing.
Look for a drawing tag on trans.

Will do and thank you

 

[dm9289]

If it is a 480 ungrounded or corner grounded system you need to make sure the panel is rated for that system.
There are panels on the market designed for 480/277 systems that, even thought they have a "480 rating", they are not suitable for 480 ungrounded or corner grounded systems
(Se 240.85 for additional information)

Thank you for your in put this one definitely is a wye

 

[augie47]

IF it's a wye you can disregard my concern about the panel rating.
Since you have no neutral going to the fused disconnect that supplies your panel, there is no neutral path available at your panel.

 

[dm9289]

I was just about to edit. I seen gfpe in drawing.
Look for a drawing tag on trans.

 

[dm9289]

I was just about to edit. I seen gfpe in drawing.
Look for a drawing tag on trans.

 

[Tulsa Electrician]

Thanks