The power company is changing the service at an older house from overhead to underground. The old service is a 3 wire meter feeding a 3 wire panel inside the house. The old panel had the main bonding jumper between the water pipe grounding electrode and the grounded conductor. The new service has a meter and overcurrent with a new Water pipe Grounding electrode conductor and main bonding jumper so the old panel's feed is now classified as a feeder. I can find how to add a new receptacle in a 2 wire system but not how to ground an existing panel in this situation. I do not believe this is an uncommon problem. I assume the grounded conductor (neutral) would bond the panel enclosure even though this is not allowed in new installs. Any thoughts. .
3 wire feeders
- Thread starter wyboy
- Start date
- Status
- Location
- Massachusetts
The only way to fix this is to run a 4 wire feeder from outside to inside and now separate the neutrals from the equipment grounding conductors at the old panel.
If it is an old panel it may not be able to have the neutral isolated and in that case you would have to swap the panel as well.
- Location
- Massachusetts
The code still requires a four wire feeder to this panel location. The EGC would ground the panel enclosure. There are no exceptions for this like there are for old ranges, dryers or panels in separate buildings.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
You could have kept the panel as the service panel if there wasn't a service disconnect added ouside. Did the utility require an outside disconnect?
- Location
- Massachusetts
That is how I see it.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
Though technically wrong, I have no problem with leaving that feeder as is and let the neutral bond the cabinet of the panel - if there are no other equipment grounding conductors landed in the panel - and you never land any new ones either meaning no new circuits out of this panel. But that is just my opinion. Once you make other connections that may have connections to ground - you have a parallel path for neutral current to flow and possible stray voltage issues can arise from that.
mwm1752
Senior Member
- Location
- Aspen, Colo
How about a shunt trip breaker for the old main, the POCO can have their disconnecting means outside & leave the three wire to panel in tact -- ask if you can use a meter with a bypass lever, the POCO could pull the meter without load issues -- demand that the POCO pay for the upgrade as it is still within the NEC & most likely was within their rules to have the this existing wiring method installed when it was installed -- I find it unusual that a POCO would demand updated regulations like this that require upgrades at your cost for equipment they do not own -- the worst scenario would be that the POCO would have to pull the meter under load in an emergency & with an older house the load would be minimal in most cases.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
If POCO is the ones doing this, or even requiring it then one might want to verify exactly where the final "service point" is.
mwm1752
Senior Member
- Location
- Aspen, Colo
Kinda goes without saying -- do you know of some that the service point is after the meter on the structure? to clarify I am still referencing this type of small service
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
No not really, but around here if a POCO is deciding to switch from overhead to underground without a request from the customer, they are usually leaving the meter where it is and not adding any service disconnecting means.
Even if not switching from overhead to underground you still get storm damaged service drops that may also have damage to the meter or riser, and those typically get replaced with same or similar with no inspections required as long as nothing beyond the meter is seeing any changes. Minor adaptations needed sometimes but are let go. So the question for the OP sort of becomes why was the service disconnect added upstream from where it originally was? If it is on POCO side of the "service point" one may question if it truly is a service disconnect per NEC.
- Status