ECN Forum Forums Code Related Discussion NEC & other Code issues Service raceway, or not?

Using an offset nipple between a meter socket and an outdoor service disconnect would require a bonding bushing where some eccentric KO rings are left intact. The nipple is considered part of a service raceway. Correct?

I would tend to think so, at least, that's the way I interepret it...

I interpret 250-80 requires this offset nipple to be bonded.

250-94(4) suggests bonding bushing or set-screw locknut.

Only one end of the metal "service" raceway needs to be so bonded.

If concentric KO's are encountered, bond both ends. Or at least the end that has any concentric KO's.

Glenn

I find it much less trouble to just use Pvc when possible. If a metal nipple was used here We would have to bond with a #6 solid Insulated (not taped) Green conductor. Try and buy that wire in a pinch.


Bill

That, and my PoCo doesn't want any bonding bushing or #4 bare in their meterbase...

I use PVC too...

I don't believe that the bonding locknut is acceptable with concentric knockouts that have portions of the KO's remaining. It doesn't serve any more purpose than would a standard conduit locknut in this case.

Bonding of this nipple (I assume it is not connected to a hub at one end, in the case of the meter socket above an outdoor rated panel) is required even if there is no concentric ko's. If it attached via a hub, no special bonding is required. If power companies don't want you in their sockets, and you need to bond it, either install a meyers hub on the panel, or install a grounding bushing inside your panel, or use a pvc nipple. Just make sure to bond the pvc with a nylon jumper!(ha-ha)

Rick Miell

It only needs to be bonded at one end, so there is no need to install something in the meter can that the utility doesn't want there.
Don(resqcapt19)

I was unaware that there needed to be a bond to a nipple. I have connected service to thousands of customers and have never seen any sort of bonding at all to a nipple. The only thing I was ever taught to look for is the plastic bushings that protects the wire from rubbing the edge of the nipple. Even in the city (Houston) where they have inspectors and require permits I have not seen this practice.

Also what good would it do if it were only bonded on one side(breaker box). If the meter-can has knockouts then how would there be true continuity tying the two boxes together? Seems like a waste of time to only install a bond to one side. But as was stated by someone earlier, the utility does not allow "any grounds" in there meter can. As also we do not either.

Without the nipple having a true bond between the boxes has helped me to troubleshoot some neutral problems. If the neutral connection was ever lost in the breaker box then the load would try to use the nipple to conduct. If not bonded then it begins to spark/burn around the KO where the nipple makes contact with the box. It has gotten to a point now where I look for this tell tale sign whenever the cust mentions dim lights.

glenn35,

Maybe it's a local thing. Here, the PoCo even made the manufacturers add a separate lug to the Meter Pan to accomodate this bonding wire. I don't know for sure if they'd call for bonding in all situations though. When they stopped allowing the wire to be taped green I went for PVC and haven't looked back.

Bill