RMC conduit going into box w/concentric KO's
 

I'm using rigid steel conduit with steel boxes where I have elected to
use the conduit as the grounding conductor. I have a 1/2" conduit
going into a masonry box with concentric 1/2 & 3/4 knockouts. I'm not
crazy about concentric KO's so I thought I'd knock out to 3/4 and use
a 3/4 to 1/2 reducing bushing where the conduit enters the box. (In
this case it would actually be an "expanding" bushing.) ... and a
locking nut on both sides of the
connection.

Isn't what I propose better than using the 1/2 knockout then praying
that the 3/4 knockout doesn't come loose? -- better for insuring a
good ground? The code does not say much about reducing bushings. I
really rather not run a separate grounding conductor.

--zeb

RMC conduit going into box w/concentric KO's
 

wrote in message
...
I'm using rigid steel conduit with steel boxes where I have elected to
use the conduit as the grounding conductor. I have a 1/2" conduit
going into a masonry box with concentric 1/2 & 3/4 knockouts. I'm not
crazy about concentric KO's so I thought I'd knock out to 3/4 and use
a 3/4 to 1/2 reducing bushing where the conduit enters the box. (In
this case it would actually be an "expanding" bushing.) ... and a
locking nut on both sides of the
connection.

Isn't what I propose better than using the 1/2 knockout then praying
that the 3/4 knockout doesn't come loose? -- better for insuring a
good ground? The code does not say much about reducing bushings. I
really rather not run a separate grounding conductor.

--zeb

Sure it is, and just spin on a 1/2" threaded grounding bushing and you'll be
well grounded

RMC conduit going into box w/concentric KO's
 

"RBM" wrote in message
...

wrote in message
...
I'm using rigid steel conduit with steel boxes where I have elected to
use the conduit as the grounding conductor. I have a 1/2" conduit
going into a masonry box with concentric 1/2 & 3/4 knockouts. I'm not
crazy about concentric KO's so I thought I'd knock out to 3/4 and use
a 3/4 to 1/2 reducing bushing where the conduit enters the box. (In
this case it would actually be an "expanding" bushing.) ... and a
locking nut on both sides of the
connection.

Isn't what I propose better than using the 1/2 knockout then praying
that the 3/4 knockout doesn't come loose? -- better for insuring a
good ground? The code does not say much about reducing bushings. I
really rather not run a separate grounding conductor.

--zeb

Sure it is, and just spin on a 1/2" threaded grounding bushing and you'll
be well grounded


I agree. The reducing bushing will look kind of hokey. Put a 1/2" bonding
bushing on after the locknut and attach a grounding pigtail to it. Once the
box and conduit are fastened securely the concentric KO should not work
itself loose.

I think running a separate grounding conductor is the best way to go.

RMC conduit going into box w/concentric KO's
 

You cannot use the conduit as the grounding conductor. Not anymore, at
least. Latest code says use a separate grounding conductor and bond it
to box.

On Tue, 14 Oct 2008 14:59:41 -0700 (PDT), wrote:

I'm using rigid steel conduit with steel boxes where I have elected to
use the conduit as the grounding conductor. I have a 1/2" conduit
going into a masonry box with concentric 1/2 & 3/4 knockouts. I'm not
crazy about concentric KO's so I thought I'd knock out to 3/4 and use
a 3/4 to 1/2 reducing bushing where the conduit enters the box. (In
this case it would actually be an "expanding" bushing.) ... and a
locking nut on both sides of the
connection.

Isn't what I propose better than using the 1/2 knockout then praying
that the 3/4 knockout doesn't come loose? -- better for insuring a
good ground? The code does not say much about reducing bushings. I
really rather not run a separate grounding conductor.

--zeb

RMC conduit going into box w/concentric KO's
 

"Rick-Meister" wrote in message
...
You cannot use the conduit as the grounding conductor. Not anymore, at
least. Latest code says use a separate grounding conductor and bond it to
box.


*Check article 344.60




On Tue, 14 Oct 2008 14:59:41 -0700 (PDT), wrote:

I'm using rigid steel conduit with steel boxes where I have elected to
use the conduit as the grounding conductor. I have a 1/2" conduit
going into a masonry box with concentric 1/2 & 3/4 knockouts. I'm not
crazy about concentric KO's so I thought I'd knock out to 3/4 and use
a 3/4 to 1/2 reducing bushing where the conduit enters the box. (In
this case it would actually be an "expanding" bushing.) ... and a
locking nut on both sides of the
connection.

Isn't what I propose better than using the 1/2 knockout then praying
that the 3/4 knockout doesn't come loose? -- better for insuring a
good ground? The code does not say much about reducing bushings. I
really rather not run a separate grounding conductor.

--zeb

RMC conduit going into box w/concentric KO's
 

On Oct 14, 9:46*pm, Rick-Meister wrote:
You cannot use the conduit as the grounding conductor. Not anymore, at
least. Latest code says use a separate grounding conductor and bond it
to box.



On Tue, 14 Oct 2008 14:59:41 -0700 (PDT), wrote:
I'm using rigid steel conduit with steel boxes where I have elected to
use the conduit as the grounding conductor. * I have a 1/2" conduit
going into a masonry box with concentric 1/2 & 3/4 knockouts. *I'm not
crazy about concentric KO's so I thought I'd knock out to 3/4 and use
a 3/4 to 1/2 reducing bushing where the conduit enters the box. *(In
this case it would actually be an "expanding" bushing.) ... and a
locking nut on both sides of the
connection.

Isn't what I propose better than using the 1/2 knockout then praying
that the 3/4 knockout doesn't come loose? *-- better for insuring a
good ground? * The code does not say much about reducing bushings. * I
really rather not run a separate grounding conductor.

--zeb- Hide quoted text -

- Show quoted text -

Yes that also would be my understanding for any 'new' work; to current
codes.
Existing conduit previously used as grounding 'might' be grandfathered
although some jurisdictions inspections may reject it if other work is
being done in same area.

RMC conduit going into box w/concentric KO's
 

"John Grabowski" wrote in message
...

"Rick-Meister" wrote in message
...
You cannot use the conduit as the grounding conductor. Not anymore, at
least. Latest code says use a separate grounding conductor and bond it to
box.



*Check article 344.60 And also 250.118







On Tue, 14 Oct 2008 14:59:41 -0700 (PDT), wrote:

I'm using rigid steel conduit with steel boxes where I have elected to
use the conduit as the grounding conductor. I have a 1/2" conduit
going into a masonry box with concentric 1/2 & 3/4 knockouts. I'm not
crazy about concentric KO's so I thought I'd knock out to 3/4 and use
a 3/4 to 1/2 reducing bushing where the conduit enters the box. (In
this case it would actually be an "expanding" bushing.) ... and a
locking nut on both sides of the
connection.

Isn't what I propose better than using the 1/2 knockout then praying
that the 3/4 knockout doesn't come loose? -- better for insuring a
good ground? The code does not say much about reducing bushings. I
really rather not run a separate grounding conductor.

--zeb

RMC conduit going into box w/concentric KO's
 

"terry" wrote in message
...
On Oct 14, 9:46 pm, Rick-Meister wrote:
You cannot use the conduit as the grounding conductor. Not anymore, at
least. Latest code says use a separate grounding conductor and bond it
to box.



On Tue, 14 Oct 2008 14:59:41 -0700 (PDT), wrote:
I'm using rigid steel conduit with steel boxes where I have elected to
use the conduit as the grounding conductor. I have a 1/2" conduit
going into a masonry box with concentric 1/2 & 3/4 knockouts. I'm not
crazy about concentric KO's so I thought I'd knock out to 3/4 and use
a 3/4 to 1/2 reducing bushing where the conduit enters the box. (In
this case it would actually be an "expanding" bushing.) ... and a
locking nut on both sides of the
connection.

Isn't what I propose better than using the 1/2 knockout then praying
that the 3/4 knockout doesn't come loose? -- better for insuring a
good ground? The code does not say much about reducing bushings. I
really rather not run a separate grounding conductor.

--zeb- Hide quoted text -

- Show quoted text -

Yes that also would be my understanding for any 'new' work; to current
codes.
Existing conduit previously used as grounding 'might' be grandfathered
although some jurisdictions inspections may reject it if other work is
being done in same area.

It's perfectly acceptable by current NEC

RMC conduit going into box w/concentric KO's
 

RMC conduit going into box w/concentric KO's
 

Thanks all for the replies.

BTW I got my permit in 2006 at which time my county was using NEC
2002.

I will definitely be using the grounding bushing to insure box-to-
conduit ground. John mentioned to use the grounding bushing after the
locknut. Couldn't the grounding bushing be used by itself? The ones
I've seen are pretty beefy compared to the locknuts. Is it code or
personal preference that you use both?

--zeb

RMC conduit going into box w/concentric KO's
 

wrote in message
...
Thanks all for the replies.

BTW I got my permit in 2006 at which time my county was using NEC
2002.

I will definitely be using the grounding bushing to insure box-to-
conduit ground. John mentioned to use the grounding bushing after the
locknut. Couldn't the grounding bushing be used by itself? The ones
I've seen are pretty beefy compared to the locknuts. Is it code or
personal preference that you use both?



I've always used the locknut then a bushing. I guess you would have to find
out from the manufacturer if their bushing was approved to function as a
locknut would. You may find that the bushing will not screw all the way
down enough to lock the pipe in place.