electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
That would not allow you to run 3 wire AFTER the meter to the house.
If you want to run three wire, you need your service disconnect at the house.
Upcoming wire pull and conduit calcs
- Thread starter Jeronimo
- Start date
If you want to run three wire, you need your service disconnect at the house.
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
Exception No. 2:
It shall be permissible to connect meter enclosures to the grounded circuit conductor on the load side of the service disconnect if all of the following conditions apply:
- (1)Ground-fault protection of equipment is not installed.
- (2)All meter enclosures are located immediately adjacent to the service disconnecting means.
- (3)The size of the grounded circuit conductor is not smaller than the size specified in Table 250.122 for equipment grounding conductors.
250.142 (B)Enhanced content:
If the grounded circuit conductor is re-grounded on the load side of the service and the grounded conductor becomes disconnected at any point on the line side of the service, the equipment grounding conductor (EGC) and all conductive parts connected to it would become energized. Under this condition, the potential to ground of any exposed metal parts could be raised to line voltage. This rise in potential on noncurrent-carrying conductive parts could result in arcing in concealed spaces and could pose a severe shock hazard, particularly if contact is made with metal piping or ductwork.
Even without an open grounded conductor, a connection between the grounded conductor and the EGC on the load side of the service places the EGC in a parallel circuit path with the grounded conductor. Exposed and concealed non-current-carrying metal parts could also be hazardous.
See also 250.30(A)(3) and 250.32(B), which prohibit the creation of parallel paths for normal neutral current.
Not creating a parallel path
Load side feed to house panel
PVC conduit
Only ground fault protection is in house panel
My drawing
Last edited:
this would be the case ANY time the grounded conductor becomes disconnected on the line side of the service?
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
250.142(B) exception 2 is only giving you permission to bond a meter socket to the grounded conductor, it's not giving you permission to do that to anything past it.
Tomorrow when you have more time can you expand and break that down barny style for me?
I'm seeing a grey area and thats why i brought it up in the first place
250.142(B) ----> 250.32(B) exception 2 ----> 250.30(a)1 exception 1
^this^
Your meter is not directly next to the service disconnecting means. You don’t get ex. 2.
But the meter enclosure IS the service disconnecting means
It has a 200A main - then a second handle of course in the house panel 245' away
In your drawing it looks like the service drop lands at your meter directly, then your service conductors run underground to the panel, making it your service disconnect.
Attachments
Right. The meter main is adjacent to the disconnect because it IS the disconnect -
There's no parallel path
I can't figure out what I'm missing or not understanding
Meter is not a disconnect.
a 200amp breaker in the meter/main panel ON THE POLE isn't considered the disconnecting means for the downstream panel?
I don't have jurisdiction to install a disconnecting means above the before the meter.
I see my mistake. That’s solves the issue I saw.
Elect117
Senior Member
- Location
- California
- Occupation
- Engineer E.E. P.E.
You are not a separately derived system.
250.32(B)(1) is your rule.
Exception 1 doesn't work.
Exception 2 is for separately derived systems.
Service conductors end at the first disconnecting OCPD. Everything down stream of the first 200A is considered an outside feeder. Sections 225 and 250.32 would apply.
See definitions in Art. 100 for Feeder, Service Equipment, and Service Conductors for more detail.
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
250.32(B)(1) Exception No. 1:
For installations made in compliance with previous editions of this Code that permitted such connection, the grounded conductor run with the supply to the building or structure shall be permitted to serve as the ground-fault return path if all of the following requirements continue to be met:
With the Meter/Main at pole every subsequent Panel is a sub-panel subject to separate grounded and grounding conductors being run after the meter/main.
For installations made in compliance with previous editions of this Code that permitted such connection, the grounded conductor run with the supply to the building or structure shall be permitted to serve as the ground-fault return path if all of the following requirements continue to be met:
- (1) An equipment grounding conductor is not run with the supply to the building or structure.
- (2) There are no continuous metallic paths bonded to the grounding system in each building or structure involved.
- (3) Ground-fault protection of equipment has not been installed on the supply side of the feeder(s).
With the Meter/Main at pole every subsequent Panel is a sub-panel subject to separate grounded and grounding conductors being run after the meter/main.
Right i had already excluded exception 1 from consideration and typo'd in my post when i meant to write exception #2
I wasnt clear in my head about the separately derived system in exception 2..