200 amp sub panel from 200 amp main (seperate building)

[MidgetD]

I work as a journeyman electrician but do not poses a residential license. However, I am allowed in my state to perform my OWN electrical work. I just built a metal building and need to run power to it.

I am planning to remove my current 200 amp (30 slot ) panel from my home and replace it with a 42 slot 200 amp panel with feed thru lugs ( lugs at bottom protected by man breaker).

I can then use my old panel in my shop as a sub panel.

I plan to run 4/0 4/0 2/0 USE wire. I will have a ground rod at the panel as well as each corner to bond the steel building. Do I have to run an equipment ground? Im unsure about that.

My other question concerns whether a seperate building is required to have a dedicated disconnect or will the homes main breaker serve the purpose.


Alternate plan would include buying a 150 amp breaker (plug in ), 150 amp main for old panel and a new 200 amp panel for the home and 2/0 aluminum wire.

 

[charlie b]

You will need a disconnecting means at the separate building. 225.32. I don't think you will have documented safe switching procedures, so I don't think you can take credit for its Exception 1. Even if you could, I don't think you would want to turn off the entire house, in order to do work on the panel in the shop.

You can only use your existing panel if it is service rated. 225.36. But given that it is presently used as your home's service panel, I don't think that will be an issue.

You will need an EGC. 250.32(B).

I don't see the purpose of putting ground rods around the building.

 

[augie47]

Allow me to suggest an alternative that might be worth thinking about.
The NEC will allow you to connect a second set of service conductors to your meter and route them to your separate building, provided they do not enter the original structure.
Your meter base would need to be rated to accept both conductors, your line side conductors would need to be rated for the total load and such an install would need to be approved by your POCO and AHJ.
In that manner there is no EGC needed.
The install would be a "service" install, the conductors would simply come from your meter rather than the POCO POA.

 

[qcroanoke]

I don't see the purpose of putting ground rods around the building.

Doesn't 250.32-A require a grounding electrode and or a grounding electrode system?

 

[david luchini]

Doesn't 250.32-A require a grounding electrode and or a grounding electrode system?

I don't think you read Charlie's post in its entirety. :happyno:

You will need an EGC.

 

[GoldDigger]

I don't think you read Charlie's post in its entirety. :happyno:

But even when an EGC is run, the fact that the circuit is going to a separate building also requires a GES at that building, yes?

 

[ActionDave]

But even when an EGC is run, the fact that the circuit is going to a separate building also requires a GES at that building, yes?

I think he is talking about the OP notion of putting ground rods at each corner of the building. I don't see any reason for that either. A bond to the building steel at one spot should be enough.

 

[augie47]

But even when an EGC is run, the fact that the circuit is going to a separate building also requires a GES at that building, yes?

You do.
(I think charlie b was noting there is no NEC requirement for a ground rod at each corner.
The OP will need a Grounding Electrode System meeting the requirememts of 250.32(A) and will need to assure building steel is bonded per 250.52(A)(2))

opps dave beat me to it

 

[MidgetD]

Charlieb
,The panel at the shop would have a Main breaker so I could isolate it at the shop panel. I just wouldn't be able to kill the underground cable without killing the house panel's main.the extra ground rods are just to ensure that the entire building is grounded mainly for lightening. overkill but I just wanted to make sure all the beams were grounded well, I installed a service on a double wide once and had to bond all the beams. So to reduce the chance of bad bonding due to paint etc I thought I'd install a few $8 rods. After all it is MY home. Your home I probally wouldn't worry about it


Augie 47, I like that suggestion as it reduces my required wire size, but wouldn't I then need a 400 amp service to my meter base? $$

Most service cables don't include a grounding conductor. So I would have to buy a seperate wire. Would it have to be insulated or can it be directly buried bare cooper?

 

[Dennis Alwon]

Midget-- you can buy individual conductors- USE that can be run in a trench if the appropriate size cable is not available.

 

[suemarkp]

Augie 47, I like that suggestion as it reduces my required wire size, but wouldn't I then need a 400 amp service to my meter base?

Either your combined load is 200A or it isn't. Using a 320/400A meter base doesn't mean there are extra costs on the utility side. Even when I had a calculated load of 375A, the utility was only willing to feed it with 1/0 aluminum which cost a few hundred more than their default size of #2 aluminum (for a 200A service).

So all this should cost you is a meterbase that can be double lugged. Hard to say what is going to cost more -- a feed thru panel and a 4th wire, or 3 wires from a 320/400 meter and a regular panel. Guess it depends on how long that run is from building to building -vs- meter to building.

 

[texie]

I think the OP should check with his POCO before setting this up as a service from the same meter as the house. While this is certainly NEC compliant and in my view a good way to do it, some POCO's require all service diconnecting means to be adjacent to the meter (which would mean that you are back where you started-needing an EGC to the out building).

 

[qcroanoke]

I don't think you read Charlie's post in its entirety. :happyno:

Yes I did.
EGC: Equipment Grounding Conductor.
GEC: Grounding Electrode Conductor
Did you read 250.32.A?

 

[MidgetD]

I am allowed to reidentify a EGC with green tape at eac termination. Correct? Article 250.119 (A). The reason I ask is that I have enough 4awg thhn black on hand and would like to use it for the EGC and just strip the insulation where it is visible.

Is this still valid if the code only calls for a #6 but I upsize to #4 because of availability?

 

[qcroanoke]

I am allowed to reidentify a EGC with green tape at eac termination. Correct? Article 250.119 (A). The reason I ask is that I have enough 4awg thhn black on hand and would like to use it for the EGC and just strip the insulation where it is visible.

Is this still valid if the code only calls for a #6 but I upsize to #4 because of availability?

Yes. #6 and larger.
250.19 (A) (2).a allows stripping the insulation from the entire exposed length.
Let me add that if you are doing direct burial THHN is not listed for that. I'm not sure that stripping all the insulation from the entire run would help either.

 

[don_resqcapt19]

I am allowed to reidentify a EGC with green tape at eac termination. Correct? Article 250.119 (A). The reason I ask is that I have enough 4awg thhn black on hand and would like to use it for the EGC and just strip the insulation where it is visible.

Is this still valid if the code only calls for a #6 but I upsize to #4 because of availability?

If the circuit conductors are part of a cable assembly, then the EGC must also be a part of that same cable assembly.

 

[jumper]

Yes. #6 and larger.

It is #4 or larger conductors that can re-identified as EGCs

An insulated #6 EGC has to be green or green and yellow striped.

 

[qcroanoke]

It is #4 or larger conductors that can re-identified as EGCs

An insulated #6 EGC has to be green or green and yellow striped.

You are correct.
Was thinking it said #6 and larger. Actually says larger than #6.
I stand corrected.

 

[jumper]

You are correct.
Was thinking it said #6 and larger. Actually says larger than #6.
I stand corrected.

I think the wording changed in the 2008 to clarify this.

 

[suemarkp]

If the circuit conductors are part of a cable assembly, then the EGC must also be a part of that same cable assembly.

Can't he pull the 300.3(B)(3) exception? As long as the cable doesn't have ferrous components, and he puts the cable and EGC in the same raceway stubs and knockout, it should be compliant.