Disconnect and Main panel

[Shawn Rowe]

Is it possible to have a "disconnect" directly adjacent to the meter (exterior) and have a Main panel in a garage.

I came across a house a few weeks ago that had a disconnect outside and a wired main panel in the garage with another disconnect (two disconnects total). I thought it needed correction but the electrician say this is to code.

Am I missing something here? can some one explain?

Sorry, I cannot find photos.

[jlybolt]

From what you describe the inside panel is a subpanel and the main means of disconnect is at the exterior. Are the neutrals and grounds seperate at the interior panel?\\

Any pictures?

[Jeffrey R. Pope]

This is where the proper terminology becomes very important. Forget "main" panel and "sub" panel. There is "service equipment" and then everything else - appliances, outlets, panels. . . what ever.

The service equipment is that which contains the service disconnect (the first point to disconnect power from the utility, after the drop or lateral, and usually directly after the meter). Everything else is "load-side" equipment.

Additional disconnects (such as that in the garage) are allowed and not uncommon, however, they must be wired differently than the service equipment, in that the neutral cannot be grounded.

All load side equipment (including additional panels) must be bonded to the service equipment and GEC via an equipment grounding conductor (EGC) or other approved means. Neutrals are to be grounded only at the service equipment (there are exceptions to that rule, but that's another story).

So, to answer your question, there is one service disconnect (located in the exterior service equipment) and an additional (or load-side) panel (located in the garage).

[jlybolt]

What Jeffrey said.

Shawn, check out elect cont eduation at
http://education.nachi.org/show.php?...element_id=251

Its some good reading.

[Shawn Rowe]

Thanks for all the responses.

Let me explain again, I understand how everything should be wired but I was curious if there were any exceptions that I have missed.

Keep in mind, it is the electrician (“the licensed expert”) that wired this that said I am wrong and he is right. I would think after 30 years in the business he would know what is correct and what is not.

I just want to make sure that my case is valid and that there are no exceptions for his wiring arrangement.

Also, Jeff can you point me to where I can read more about this:

Neutrals are to be grounded only at the service equipment (there are exceptions to that rule, but that's another story).

The neutral at the service disconnect was NOT grounded. (I am sorry but I cannot find the photo)

[Paul W. Abernathy]

Going above that...I will add......YES you treat the panel in the garage as a SUB panel or as we really should call it " Remote Distribution Panel " but nothing says it can't also have a OCPD on it.....does not have to be a Main Lug Only panel....

IN fact we find it cheaper to place a normal panel and set it up as a 'SUB" panel with isolated netural and so on and grounding bar......4 wire setup.....but still have a OCPD controling the panel at this location also....nothing says you can't have a OCPD at both ends...

What is important is the FIRST Main Disconnect MUST be sized to protect the conductors to the SUB panel.

[Shawn Rowe]

So Paul, under no circumstance should the neutral not be grounded at the service panel. No exceptions, RIGHT?

[Paul W. Abernathy]

Originally Posted by srowe

Thanks for all the responses.

Let me explain again, I understand how everything should be wired but I was curious if there were any exceptions that I have missed.

Keep in mind, it is the electrician (“the licensed expert”) that wired this that said I am wrong and he is right. I would think after 30 years in the business he would know what is correct and what is not.

I just want to make sure that my case is valid and that there are no exceptions for his wiring arrangement.

Also, Jeff can you point me to where I can read more about this:


The neutral at the service disconnect was NOT grounded. (I am sorry but I cannot find the photo)

OK........As Jeff said...at the MAIN Disconnect or Service Disconnect which is the FIRST one.....the grounded conductor IS on the same buss at the grounding....it is the PANEL downstream on the load side that SHOULD NOT have the grounded and grounding conductors together....

Here is an image for you of WHY....



Ok.....this is not the BEST picture to explain this....IGNORE the conduit if it does not apply......and the verbage about the grounding conductor connection and so on.....

The reason I post it is because it is similar to your question in regards to the setup...notice the service disconnet and the panel setup...

Now in this they are only running the Grounded and Grounding conductor to show you HOW they sepatate in the panel.....BUT ofcourse in REAL life you would also have (2) Ungrounded conductors as well....this image just shows you need to seperation at the panel.....

The requirement to not have a Neutral to Case bond which would REQUIRE the 4 wires is Art. 250.6(A) and the image below is again the best I can find to explain it......so ignore the conduit in the image...and assume that it is the ground wire...But it explains WHY at the panelboard in the garage should not have the 3 wire setup and the neutral bonded to the case.....in Art. 250.142(B) is the actual article you are looking for if in fact you are...lol



(B) Load-Side Equipment. To prevent dangerous voltage on metal parts, the grounded neutral conductor must not be bonded to the equipment grounding (bonding) conductor on the load side of service equipment, except as permitted by 250.142(A).

Exception 1: The grounded neutral conductor can serve as the effective ground-fault current path for existing ranges, dryers, and ovens

Exception 2: The grounded neutral conductor can be bonded to the meter enclosure on the load side of the service disconnecting means

Anyway...pictures are nice to look at anyway.... I sure wish mike would make some images that DONT use conduit........but I think you get the picture....

[Paul W. Abernathy]

Originally Posted by srowe

So Paul, under no circumstance should the neutral not be grounded at the service panel. No exceptions, RIGHT?

No their are exceptions...but they more or less pertain to Detached Buildings...if the garage is attached to the dwelling it SHOULD NOT be run in 3 wire.....it should have (4) conductors......unless it was run in Conduit which can serve as the grounding conductor....but VERY rare......Mr. Decker may see it more than most in Chicago...we dont here in VA or areas where NM and SER are used.

See my images and examples I posted above this......

If the SERVICE panel is directly after the meter cab and the OCPD is within that Service Panel.....it MUST have the Grounded and Grounding conductors on the same buss and the panel bonded to this buss...it is ONLY after it leaves this panel does it have to be seperated.....if it goes to a "Remote Distribution Panel" (ie: Sub Panel )

[Shawn Rowe]

Your explanation is more than enough, your last post is exactly what I wanted!!
Thanks for going out of your way to help!

[Paul W. Abernathy]

Shawn,

Just remember...that disconnect BY the meter...is the Main Service Disconnent.....the panel in the garage IS considered the 'Remote Distribution Panel " and would need to have (4) wires going to it....if attached....

Gets more complicated if the Garage is Detached..so we wont go their...

Actually I answered this for you so you will provide BOARDING when I come down to St. Augustine and play golf...thehehehe

I LOVE that city.....thats where I want to retire in...ohhhhh.....40 years !