bonding rigid conduit riser : on the buss

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wyreman

Senior Member
Location
SF CA USA
Occupation
electrical contractor
Inspector here suggested I land the gas bond on the 1-1/4" RMC utility riser as it approached the meter.
He explained that was a simpler way to bond it than to go all the way into the enclosure.
Just run a #4 from a clamp on the nearest point on the gas to a clamp on the utility riser.

I knew you can land all the rods and bonds you want on the first 5 feet of the water pipe, if the water then has the right size GEC to the main...
but can bond the water, gas or rods to the RMC utility riser?
I guess it's not much different than bonding it in the enclosure on a buss

I like it but have I been doing it the hard way?
I thought:
The grounding electrode conductor shall be continuous (without bolted splices) from the grounding electrode to the neutral connection.
and the RMC is not exactly the neutral connection
So I could land the rods, and the gas all to the riser if need be, since it's all service equipment and threaded together?
just not the water
 
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jumper

Senior Member
I am going to say no to using the RMC riser as a place to attach the GEC to the service. The riser merely contains the service drop conductors, it is not one one of them, and it not a terminal or bus that connects to the grounded conductor.

250.24 Grounding Service-Supplied Alternating-Current
Systems.
(A) System Grounding Connections. A premises wiring
system supplied by a grounded ac service shall have a
grounding electrode conductor connected to the grounded
service conductor, at each service, in accordance with
250.24(A)(1) through (A)(5).
(1) General. The grounding electrode conductor connection
shall be made at any accessible point from the load end
of the service drop or service lateral to and including the
terminal or bus to which the grounded service conductor is
connected at the service disconnecting means.

Informational Note: See definitions of Service Drop and
Service Lateral in Article 100.

Service Lateral. The underground conductors between the
utility electric supply system and the service point.

Service Drop. The overhead conductors between the utility
electric supply system and the service point.

Now as far as bonding the gas line to the riser, again I am going to say no. The riser is not listed as an acceptable point of attachment.

(B) Other Metal Piping. If installed in, or attached to, a
building or structure, a metal piping system(s), including
gas piping, that is likely to become energized shall be
bonded to the service equipment enclosure; the grounded
conductor at the service; the grounding electrode conductor,
if of sufficient size; or to one or more grounding electrodes
used.
The bonding conductor(s) or jumper(s) shall be
sized in accordance with 250.122, using the rating of the
circuit that is likely to energize the piping system(s). The
equipment grounding conductor for the circuit that is likely
to energize the piping shall be permitted to serve as the
bonding means. The points of attachment of the bonding
jumper(s) shall be accessible
.
 

wyreman

Senior Member
Location
SF CA USA
Occupation
electrical contractor
I agree about the GEC because the enclosure certainly isnt the neutral wire

but for the bond...
Isn't the rmc just part of the enclosure?

You can strap the bonding wire to any point in the can
The RMC is really just a part of the can.
Its "connected at the service disconnecting mean." isn't it?
bonded to the service equipment enclosure

The clamp is listed.

Because this inspector is usually a hard hatss
and he not only ok'd it, but suggested it.
I think highly of him
 
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jumper

Senior Member
The RMC is not part of the enclosure, it is merely a conduit attached to it.

I have no clue as why the inspector says this is legal.

I will say that using the riser as an attachment point may provide a safe bond, but as written, I do not see it as code legal.
 
Lots of interesting views here. Good discussion. Question: where does it say that a bonding jumper has to be copper? Or that it has to be non-spliced? I posit that the RMC riser is a valid bonding conductor and thus a copper conductor bonded to the riser provides and effective fault current path to the service panel as require per 250.4(A)(4).
 

wyreman

Senior Member
Location
SF CA USA
Occupation
electrical contractor
I'm here again

I need to bond the gas to the grounding electrode and the only thing I've got is this

image.jpg image.jpg

In this case the rigid is the grounding electrode conductor is in it?
 

meternerd

Senior Member
Location
Athol, ID
Occupation
retired water & electric utility electrician, meter/relay tech
I'm here again



In this case the rigid is the grounding electrode conductor is in it?

I'm confused....(not unusual for me). Are those service conductors or are they downstream of the meter and service disconnect? If it's part of the service entrance conductors, it's non-compliant. No bonding bushings, no enclosure bond, not a sealable panel, etc. I'd be surprised if your utility would let it fly. If it's downstream of the meter/disconnect, how would the rigid conduit (if you're saying it's a GEC) bond to the grounded conductor at the "load end" of the service conductors? Weird
 

wyreman

Senior Member
Location
SF CA USA
Occupation
electrical contractor
This is a three wire is subpanel feed done in rigid conduit
So the ridgid is the grounding means

Where is the grounding electrode conductor than that I can buy on my gas to?

I guess the point is they used to let you bond the gas to the waterpipe anywhere but now it's got to be sure to hit the GEC

What is the GEC in a three wire sub feed to a panel when this is Run in rigid
 
This is a three wire is subpanel feed done in rigid conduit
So the ridgid is the grounding means

Where is the grounding electrode conductor than that I can buy on my gas to?

I guess the point is they used to let you bond the gas to the waterpipe anywhere but now it's got to be sure to hit the GEC

What is the GEC in a three wire sub feed to a panel when this is Run in rigid

Is it a GEC? No. I though you were originally saying that the RMC was containing a service to a main panel but from your last post it is just a EGC.
 

electricalist

Senior Member
Location
dallas tx
I'm confused....(not unusual for me). Are those service conductors or are they downstream of the meter and service disconnect? If it's part of the service entrance conductors, it's non-compliant. No bonding bushings, no enclosure bond, not a sealable panel, etc. I'd be surprised if your utility would let it fly. If it's downstream of the meter/disconnect, how would the rigid conduit (if you're saying it's a GEC) bond to the grounded conductor at the "load end" of the service conductors? Weird
You have unriddled the riddle batman. This could not be any type of bonding means for a GEC. If it were then a GEC would be present just because the sub panel will eventually in some/ many ways some where end up bonded to at least bldg steel.
 

kwired

Electron manager
Location
NE Nebraska
The grounding electrode conductor lands at the service equipment or the main disconnect at a building supplied by a feeder from another building. Separately derived systems also require a grounding electrode - and it should tie to the grounding electrode system for the rest of the building in some way - typically to building steel if it is available.

A raceway is not a grounding electrode or a grounding electrode conductor.


A raceway can be used as an equipment grounding conductor though.
 
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