Pulled the neutral short -- so had to splice it to get up to the neutral rail -- embarrassing waste of an insulated splice.
Where's the white tape banding the neutral as it hits the neutral rail?
Banding white tape over a red conductor explains where all the white tape went, hence no band on the neutral conductor.
I assume that the puppy at the right is a house panel and that it's feeding a light circuit scheme with a photo cell mounted high.
Everything looks NEMA3R while the mounting board is naked plywood. (?)
The missing bushing at the Poco entry/ GEC permits insects graceful access to the space -- not something that'd fly around here.
The neutral for the very first, upper left, residence seems undersized. (#6?) It may be okay if the unit is sucking down 240 Amps... but a #4 or larger would be required down my way. ( Typically, our systems are 3-phase, so the neutral can't be downsized at all. I now see that this is a 1-phase Service. )
You, indeed, have bonding bushings for the Poco feeders. What I don't see is a neutral to GEC bond in the fashion I'm accustomed to: EURSEC demands that a mechanical link between the GEC and the neutral exist so that Poco employees can un-link them in a snap for various testing purposes -- whether this happens in a life-time or not.
In any event, the GEC would not be permitted to terminate on bonding bushings alone: it'd have to be lugged to the chassis -- paint scraping and all.
As for pure style opinion: as forman, I hated LBs and top entries: too leak prone, slow and expensive.
I always would take the low route so that all top side surfaces were sealed to the elements. Having inspected plenty of old work, I've seen no end of water invasion as top side elements work free over time.
By merely re-jiggering the scheme: pass from six-pack to house panel with a single straight EMT pipe on the down low... say 4" in between... place the photo-cel vertical off towards the right -- now a very easy install without a trick elbow -- two nineties permit it to whip tight to the right edge of the house panel from the center, bottom -- if that looks best -- else use just a common ninety off the right, lower....
1/2" EMT bends like rubber -- a straight entry into the house panel is s o o o much quicker than an LB -- that any extra wire needed is a joke -- and the look is less cluttered, too. Savings: nipple, LB, factory tight-ninety.
Possible bottom feed of house panel. ( NEMA3R panels of this type commonly permit the bussing to be flipped in the field. )
Hi, Thanks for the replies. I did not do this work myself. A friend did the work and the state inspector told him he needed to have it checked out by a master. I agree I have seen a lot better work and would not have done this the way it is.
The person who did this is NOT an electrician. The 6 pack does not feed a house. The riser has a light on top of it. fed by a GFI which is fed by a single pole switch.
The GEC goes from bushings to neutral bus near one of the mains where it terminates.
I believe you are referring to supply side bonding which I will pass on to them unless I am misunderstanding.
The whitish conductor is NOT a #6 in white -- it's the feeder GROUNDING Conductor -- and the Neutral is not banded white, such that I can see.
That grounding conductor is improperly lugged to the Neutral Bar -- it belongs down at the bottom where you'll barely see Grounding Rails under each meter stack, left and right.
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I missed it, but the top bus is the neutral bus and it DOES have a neutral to grounding bus link -- the tiny thing up at the extreme NorthEast -- and the chassis is made integral to the Grounding Electrode Conductor scheme -- which would, it seem, require that the GEC at the lower left be lugged to bare metal at the chassis.
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With only six meter sockets, I'm assuming that the Poco feeds this six-pack without any intervening disconnecting means -- and that the GEC heads on down into the ground as a Ufer/ ground ring, per the NEC.
"One more thing, is it allowed to run a 4/0 EGC through a knockout/hole in the six pack to ground? I was thinking there should be a bushing there. (anything larger than #4)."
I can't see all of this in the pic, but are you refering to the utility pull section at the left? With a bare GEC from the two bonding bushings exitint at the right rear corner?
There is at least one (1) connector mfg for 'bonding'/'choking' the EGC to the enclosure. Trade name is 'Kenny clamp' you can google that for visuals. There are competing brands around.
That connector is $$ compared to a PVC TA, and a stick of PVC, which is a common choice over here.
IMHO, the 'splice' in the neutral with the kupl tsp should have been a crimp splice, although it is not a violation; just workmanship. As an EC I would not accept that.
I googled Kenny clamp -- and got into a thread/ forum confused WRT what the 'choke effect' is....
In that thread, the term was very often misspelled as chock, etc.
Choking current flow is by way of ferrous magnetic properties -- the very same ones used to make transformers and motors work.
The original 'ballast' on old style fluorescent lamps was a CHOKE -- i.e. inductance element -- that stopped too much alternating current from burning out the tube during run time.
At the extreme, EVERY time a conductor passes through ferrous objects/ even wraps nearby, around such edges or stacked plates ( transformers ) the current flow is thwarted by the ferrous / steel / iron / nickel, etc. which is interacting with the (normally 60Hz) magnetic flux of the current.
In the event of fault currents ( lightning strikes in particular ) the amount of current that can travel up/down the GEC is ASTOUNDING -- many, many times the current a j-man assumes. [ Try 10,000 instantaneous amps on UP ]
Further, lightning does NOT strike but once -- ever. ( apparently ) Instead, it flashes much faster than the eye can perceive -- and is best detailed in the recent War of the Worlds flick as the film crew slows down real arcing action to embed photoshopped bad guys.
The current best theory as to what drives lightning -- in the ultimate -- is COSMIC RAYS. Yup.
The Earth is perpetually bombarded with cosmic rays -- which, on balance deposit a net electron balance to the surface of the planet. An electron deficit is imparted to the clouds. ( IIRC, I could be getting the polarity reversed. ) Eventually, this gigantic capacitor effect is resolved in storm conditions -- particularly in thunderheads -- with their massive updrafts -- into channels of dis-continuous current: lightning.
Florida is the national capital of lightning records - by far. It's so bad that the rocket complexes have massive lightning towers built around the pads -- four per -- solely to shunt electrons away from the rockets. You can see them in the Falcon 9 launch footage.
Not withstanding the fact that the choke effect is there -- even when the GEC is passing through trivially thin panel metal skin -- no inspector I know has even complained about a 'PVC solution.' That is, an unbonded GEC is permitted to pass out of panels if it is not wrapped in ferrous conduit. ( no GRC, IMC, EMT, steel flex, etc. )
The Kenny solution is elegant -- but is not economically favored: other common devices do the same job.
It also does not mate well with conduit -- and exposed GECs are going to be cut to pieces by meth heads from here on out.
As for the above GEC, I'd go with the PVC raceway solution -- and would not slow down to bond the GEC as it exits the pull section.
A separate low voltage bonding lug or two should be set for the cable TV guy and phone fella, too.
The six-pack chassis is plainly designed to be integral to the GEC system --as it's the only conductor that links the neutral-grounding bond strap -- inspect the picture at the extreme NorthEast for the removable link.
The site of the mfg of the Kenny Clamp has a lot of info, yes, it does trumpet the item as the best thing since sliced bread, etc.
Conductor size specific, Cu only, and some may say "pricey".
At it's introduction, it was touted as the only 'listed' (UL/CSA) connector for GECs. That lead to some AHJs failing other 'previously accepted' 'connectors' for GECs. Much debate later, the State DCA edict was..."listed connector, 1/4" nominal KO in backbox, or chase nipple with GEC secured outside enclosure at <6". Done.
The mfg data leans heavily towards lightning related issues more than creating a 'choke' point. I have a PowerPoint from the mfg somewhere in my collection.
Tesla: how can an 'unbonded GEC' exit an enclosure? The enclosure should/must/is bonded at the N bar is its the first disco, or there must/is a GB bonded within the backbox.?? Theory please!!
If I just wanted to "get r done" I would use a Romex connector. Electrically pretty effective, legally, not so much.
All that said, here in the lightning capital, you are usually going to see a PVC sleeve on the GEC. EMT tends to rot out at ground level, making a big choke.
Greg: You hit the nail on the head with the NM connector. That's what was 'OK' for so many years. 'Chokes' were made with a lot of 'on the truck parts'; nipples, couplings NM connectors, etc. for metalic raceways & 'those damm ground wires'.
Again, I see the confusion of what, exactly, a 'choke' is.
The comment about lightning being the issue is EXACTLY a reference to the choke effect. Choking of fault current -- is the only time that choking is at issue at all.
It's a phenomenon only seen AFTER a disaster -- or in specially constructed test rigs of very high power. IIRC, Tesla, himself, was the original researcher in this area.
As an electrician, one must put behind you ALL that you think you know about current flow when you're talking about extreme high powered PULSES of power. Stuff that would not normally conduct/ be any issue -- or be a serious inductive element -- comes into play.
With lightning, juice is jumping clean through the air (!) normally our very best insulator.
Choking on GECs is 100% a FAULT CONDITION CONCERN, only. To describe concern about lightning is to describe the concern about permitting a ferrous ( anything steel/ iron/ nickel/ etc. ) to ELECTROMAGNETICALLY slow down the flow of these pulses between the Earth and the sky -- ruining the equipotential plane that we all know and love.
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There is also clear cut confusion here, and on the other forum's thread, about what bonding a GEC means -- in this context.
To elaborate: there are bonds and there are bonds...
Good design has ONLY ONE BOND BETWEEN THE NEUTRAL AND THE GEC.
In the photo above you can see where that bond/ link is: the NorthEast corner clearly shows the aluminum bus link that jumps from the top, neutral rail, down to the chassis -- which is made integral to the GEC SYSTEM.
To recap: the ENTIRE chassis has been made an element of the GEC system in this instance -- the neutral conductor, from the Poco remains isolated from the chassis all the way to the top rail -- until it meets that link. Appended to that top rail are twin neutral rail lug bars - which are obviously kept isolated from the chassis.
That N-G link is what the above posters are thinking of when they write of a GEC having 'only one point of bonding.' Left unsaid: 'only one point of bonding WITH THE NEUTRAL CONDUCTOR SYSTEM.'
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Again, direct examination of the photo shows us that the GEC is BONDED to the lay-in lugs at the Sealtite entry, twice, as it happens. It still needs to be bonded to the chassis with a specific lug, usually a mechanical lug -- paint scraping and the whole nine yards.
It should either be bonded, yet again, on its way out of the pull section -- IF it passes through an element/ raceway that would present choking conditions ( EMT, GRC, IMC, Flex-steel, etc. ) and then bonded yet again as the GEC left that same raceway on down into the Ufer/ ground ring, etc.
So, the GEC gets bonded and re-bonded every step of the way back down from the neutral bonding link so that -- in the event of faults -- no inductive elements choke back the pulse -- thus breaking the harmony of an equipotential plane.
All of the above is why we keep using lay-in lugs and bonding all over in SDS/ transformer schemes. Those are an endless string of bonds on the GEC, too.
And lastly, the GEC system has bonds all over it -- to the metallic gas distribution -- to the water distribution system -- to the heavy steel of the building -- to the hot water side of the potable water system -- to the low voltage data-com system, etc.
ALL of those are bonds to the GEC. It gets bonded all over.
BUT, it's supposed to be bonded to the Neutral System at only one place. That place is so special we give it unique terminology, when the link is active we say: the system is GROUNDED and the neutral is the GROUNDED CONDUCTOR.
When that link is lifted we say: it's an UNGROUNDED SYSTEM and that the return conductor is UNGROUNDED/ floating -- or a HIGH IMPEDANCE GROUND. [ This last item is mostly restricted to industry -- you won't find it permitted anywhere else. ]
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Until lightning does it in, the GEC system is never really stressed. So one can get away with just about anything -- and the install will still work.
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EMP pulse attack is constantly in the news -- many fear the Iranians will use such a gambit. I don't. But, EMP is like lightning on steroids. With it, we'll see just how many installations have unwitting chokes on their GEC paths to ground.
The term 'choke' comes from EE circles -- and is short hand for INDUCTIVE CURRENT RESTRICTION.
Steady state DC current is opposed by resistance, check.
Steady state AC current is opposed by impedance, check.
Impedance is composed of; resistance PLUS inductance PLUS capacitance factors.
In our circuits, capacitance effects don't much figure into fault current -- unless you, rightly, consider lightning to be the discharge of a staggeringly large capacitor - from Earth to sky.
Instead, resistance and inductance, do. We size our GEC to handle the resistance based upon the cross section of the conductors exposed to fault current without OCPD.
All that remains is to make sure that we've not introduced any inductive chokes -- which disappear when the AIR GAP between the steel and the copper is eliminated by bonding the GEC -- yet again.
We bond to make various elements One equipotential plane. We bond all over the field wiring. We bond the neutral to the GEC system at ONLY one spot -- which can be broken at a later date for the purposes of testing OCPD -- particularly circuit breakers.
In major installations, such breaker tests can occur every year. The bigger the breaker, the more paranoid the owner, hence the design.
