SSBJ needed?

[SceneryDriver]

Saw a service today as follows:

Underground 200A service to the meter pedestal. Out of the back of the meter pedestal through the sill plate with 2" FMC. FMC runs about 3' to a 12" x 12" j-box. 2" EMT runs from down from there into the panel. Main breaker is in the panel.

Neutral is bonded to the meter can. The service conductors are spliced in the 12" x 12" j-box with Polaris connectors, and the j-box is labeled as "Line side tap location for future solar service." A #4 green wire is brought up to a small ground bar in the j-box (presumably for future solar interconnection) from the panel's ground bar. N-G bond is in the main panel via the green bonding screw. Ufer ground and water bond land in the panel as well.

I was asked if #4 supply-side bonding jumper (correct terminology?) should accompany the service conductors through the FMC out to the meter pedestal? If yes, what purpose would it serve, with the meter pedestal being bonded to neutral, and the EMT / #4 bonding the j-box from the panel-end? Where to land the bonding jumper in the meter pedestal?

My contention is that the service is fine as installed; FMC isn't listed as a bonding/grounding means, the neutral connection to the meter can bonds it, and G & N are properly bonded at exactly one point in the panel (first means of disconnect). The j-box and EMT are properly bonded by the #4 wire to the j-box ground bar, as there are concentric KO's on the panel-end of the EMT run, but the j-box is field-punched at 2".

What say you all?



SceneryDriver

 

[electrofelon]

My take is that you need a BB or BL on one end of the EMT. You also need a BB or BL on one end of the Flex. Also, IMO if you bonded both ends of the EMT, then you could skip the #4 wire going up to the J-box. If I am wrong, Ill just say I misunderstood the description

 

[SceneryDriver]

My take is that you need a BB or BL on one end of the EMT. You also need a BB or BL on one end of the Flex. Also, IMO if you bonded both ends of the EMT, then you could skip the #4 wire going up to the J-box. If I am wrong, Ill just say I misunderstood the description

See, this is why I asked.

Why would the EMT need a bonding bushing and lug? I believe it gets its bond through the j-box, as it's a non-concentric KO. Was I wrong, as this is a service? The j-box is bonded with the #4 wire running to its cute little ground bar.

Why would the FMC need a bonding bushing? It's in a non-concentric KO in the j-box (so it itself is bonded), and isn't listed for bonding between enclosures anyway. Doesn't the neutral connection to the meter pedestal take care of the meter end bond?

The bonding bushings are simple enough to add (now that they make split bonding bushings) but I wasn't entirely sure they were necessary, based on the install. The FMC threw me off a little, so I asked here.

I was told that the previous service, before the work was done, had a run of 2" PVC between the meter pedestal down to the panel. With non-metallic conduit, it's pretty straightforward. Throw in that FMC, the j-box, and the EMT, and it gets a little more complicated.




SceneryDriver

 

[nickelec]

From NYC amendments

(10) Flexible metal conduit not over 1.83 m (6 ft) long or liquidtight flexible metal conduit not over 1.83 m (6 ft) long between raceways, or between raceway and service equipment, with equipment b onding jumper routed with the flexible metal conduit or the liquidtight flexible metal conduit according to the provisions of Section 250.102(A), (B), (C), and (E).

Sent from my SM-G950U using Tapatalk

 

[nickelec]

230.43 Wiring Methods for 600 Volts, Nominal, or Less. Serviceentrance conductors shall be installed in accordance with the applicable requirements of this Code covering the type of wiring method used and sh all be limited to the following methods:
(1) Type IGS cable.
(2) Rigid metal conduit.
(3) Intermediate metal conduit.
(4) Electrical metallic tubing.
(5) Metallic wireways.
(6) Busways.
(7) Metallic auxiliary gutters.
(8) Rigid nonmetallic conduit,
(9) Mineralinsulated, metalunderground. sheathed cable.
(10) Flexible metal conduit not over 1.83 m (6 ft) long or liquidtight flexible metal conduit not over 1.83 m (6 ft) long between raceways, or between raceway and service equipment, with equipment b onding jumper routed with the flexible metal conduit or the liquidtight flexible metal conduit according to the provisions of Section 250.102(A), (B), (C), and (E).


Service entrance conductors shall not run within the hollow spaces of frame buildings.

Sent from my SM-G950U using Tapatalk

 

[SceneryDriver]

So, we all agree that a bonding jumper should've been installed in the FMC with the service conductors. Where should it land in the meter pan? I didn't look (meter pedestal was sealed), but there may or may not be a place to land it. Tag a lug to the meter pan and land it there?

What does the #4 wire do that the 2/O neutral doesn't already take care of, since the neutral is bonded to the meter enclosure, and neutral and ground are bonded in the panel? Is this the same "parallel paths for current" issue that we make such a fuss about on the other side of the main breaker? Am I correct that there wouldn't be a need for a SSBJ if the conduit was PVC, or another nonmetallic wiring method was used?

I think someone here said something about electrons making sure to pay close attention to the color of the wire when on the service side; how nice of them

I'll recommend that a #4 SSBJ be added in the FMC whip. No idea if it will actually get done, but all they asked for was a recommendation.



Thanks,

SceneryDriver

 

[electrofelon]

IMO you still need a BB or BL on one of the FMC connectors and the EMT connector. See 250.92(B). Think of it this way: A fault anywhere on the equipment or stuff enclosing service conductors has to be able to get back to the neutral by one of the connections listed in 250.92(B). The bonding jumper around the flex will pass a fault between the enclosure at each end, but IT does nothing for a fault to the flex itself. That is why the BB/BL is there.