I'm having trouble reconciling various information I keep reading
regarding grounding on a sub-panel. I have a detached garage that I'm
installing a subpanel in. The inspector said to drive 2 ground rods,
which I've done, but now I have a couple questions.

In regards to the bonding strap in the subpanel, I've read the
following: 1) don't use it in the subpanel, 2) always use it and 3)
only use it if it's used in the main panel. So which is it? I've
separated neutral and ground in the subpanel, so I see no reason why I
would need it.

And as far as bringing the #6 bare copper wire from the ground rods,
how do I physically bring them into the box. I can't imagine I have
to use a clamp through a knock-out. Can I just drill a hole in the
side of the box to bring the wire into the grounding bar? If not, how
am I supposed to do it - I can't find any specific information on that
aspect of the grounding wire.

thanks,

danbo

In article .com, danbo wrote:
I'm having trouble reconciling various information I keep reading
regarding grounding on a sub-panel. I have a detached garage that I'm
installing a subpanel in. The inspector said to drive 2 ground rods,
which I've done, but now I have a couple questions.

In regards to the bonding strap in the subpanel, I've read the
following: 1) don't use it in the subpanel, 2) always use it and 3)
only use it if it's used in the main panel. So which is it? I've
separated neutral and ground in the subpanel, so I see no reason why I
would need it.

#1 is required (and #2 and #3 prohibited) by the National Electrical Code.

And as far as bringing the #6 bare copper wire from the ground rods,
how do I physically bring them into the box. I can't imagine I have
to use a clamp through a knock-out.

Imagine it. Then do it.

Can I just drill a hole in the
side of the box to bring the wire into the grounding bar?

No.

If not, how
am I supposed to do it - I can't find any specific information on that
aspect of the grounding wire.

With a clamp through a knockout -- which is easiest and fastest, properly
secures the wire to the box, and raises no issues of Code compliance. Why
would you want to do it any other way?

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

You would not use the bonding jumper in this situation, with one exception.
The exception being that the driven grounding conductor is the ONLY
grounding conductor at the detached building, No grounding conductor run
with the feeder, and nothing conductive linking the detached building and
the main building other than a neutral conductor and two ungrounded
conductors


"danbo" wrote in message
oups.com...
I'm having trouble reconciling various information I keep reading
regarding grounding on a sub-panel. I have a detached garage that I'm
installing a subpanel in. The inspector said to drive 2 ground rods,
which I've done, but now I have a couple questions.

In regards to the bonding strap in the subpanel, I've read the
following: 1) don't use it in the subpanel, 2) always use it and 3)
only use it if it's used in the main panel. So which is it? I've
separated neutral and ground in the subpanel, so I see no reason why I
would need it.

And as far as bringing the #6 bare copper wire from the ground rods,
how do I physically bring them into the box. I can't imagine I have
to use a clamp through a knock-out. Can I just drill a hole in the
side of the box to bring the wire into the grounding bar? If not, how
am I supposed to do it - I can't find any specific information on that
aspect of the grounding wire.

thanks,

danbo

"danbo" wrote in message
oups.com...
I'm having trouble reconciling various information I keep reading
regarding grounding on a sub-panel. I have a detached garage that I'm
installing a subpanel in. The inspector said to drive 2 ground rods,
which I've done, but now I have a couple questions.

In regards to the bonding strap in the subpanel, I've read the
following: 1) don't use it in the subpanel, 2) always use it and 3)
only use it if it's used in the main panel. So which is it? I've
separated neutral and ground in the subpanel, so I see no reason why I
would need it.


#1 is correct.


And as far as bringing the #6 bare copper wire from the ground rods,
how do I physically bring them into the box. I can't imagine I have
to use a clamp through a knock-out. Can I just drill a hole in the
side of the box to bring the wire into the grounding bar? If not, how
am I supposed to do it - I can't find any specific information on that
aspect of the grounding wire.


Just use a two screw Romex connector in a 1/2" knockout. You need to have
some strain relief.

In article , wrote:

Either run a 4 guage to the ground rod (the easy answer) or buy some
PVC conduit to sleeve your #6. That will also go into the 1/2" KO and
put that question to bed.
It is code that anything less than 4 needs a conduit.

No, it's not.

"A 6 AWG grounding electrode conductor that is free from exposure to physical
damage shall be permitted to be run along the surface of the building
construction without metal covering or protection where it is securely
fastened to the construction; otherwise, it shall be in rigid metal conduit,
intermediate metal conduit, rigid nonmetallic conduit, electrical metallic
tubing, or cable armor. Grounding conductors smaller than 6 AWG shall be in
[the same types of conduit]." [2005 NEC, Article 250.64(B)]

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article , wrote:
On Fri, 06 Jul 2007 11:55:17 GMT, (Doug Miller)
wrote:

No, it's not.

"A 6 AWG grounding electrode conductor that is free from exposure to physical
damage


Most inspectors say that is exposed to physical damage.

Perhaps -- but that's the inspector's call. The *Code* says 6 AWG doesn't
necessarily have to be in conduit.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Jul 6, 12:40?pm, (Doug Miller) wrote:
In article , wrote:
On Fri, 06 Jul 2007 11:55:17 GMT, (Doug Miller)
wrote:

No, it's not.

"A 6 AWG grounding electrode conductor that is free from exposure to physical
damage

Most inspectors say that is exposed to physical damage.

Perhaps -- but that's the inspector's call. The *Code* says 6 AWG doesn't
necessarily have to be in conduit.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

i ran a tiller into my service entrance cable, after the tiller hit a
rock.

spark city and could of easily died that day

In article .com, " wrote:
On Jul 6, 12:40?pm, (Doug Miller) wrote:
In article ,
wrote:
On Fri, 06 Jul 2007 11:55:17 GMT, (Doug Miller)
wrote:

No, it's not.

"A 6 AWG grounding electrode conductor that is free from exposure to
physical
damage

Most inspectors say that is exposed to physical damage.

Perhaps -- but that's the inspector's call. The *Code* says 6 AWG doesn't
necessarily have to be in conduit.

i ran a tiller into my service entrance cable, after the tiller hit a
rock.

spark city and could of easily died that day

What was your service entrance cable doing that close to the surface and not
in conduit?

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Jul 6, 2:41?pm, (Doug Miller) wrote:
In article .com, " wrote:





On Jul 6, 12:40?pm, (Doug Miller) wrote:
In article ,
wrote:
On Fri, 06 Jul 2007 11:55:17 GMT, (Doug Miller)
wrote:

No, it's not.

"A 6 AWG grounding electrode conductor that is free from exposure to
physical
damage

Most inspectors say that is exposed to physical damage.

Perhaps -- but that's the inspector's call. The *Code* says 6 AWG doesn't
necessarily have to be in conduit.
i ran a tiller into my service entrance cable, after the tiller hit a
rock.

spark city and could of easily died that day

What was your service entrance cable doing that close to the surface and not
in conduit?

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.- Hide quoted text -

- Show quoted text -

1950s home, all of them in the neighborhood that way. cable enters
high up on garage wall.......

oddly enough they replaced it the same way. but that was maybe 1980s.

You are correct , but personally, I've never used smaller than #4 regardless
of service size. The difference in cost is minimal, and it eliminates the
possibility of an anal inspector giving you problems, or at least he has to
be more creative



"Doug Miller" wrote in message
.. .
In article ,
wrote:
On Fri, 06 Jul 2007 11:55:17 GMT, (Doug Miller)
wrote:

No, it's not.

"A 6 AWG grounding electrode conductor that is free from exposure to
physical
damage


Most inspectors say that is exposed to physical damage.

Perhaps -- but that's the inspector's call. The *Code* says 6 AWG doesn't
necessarily have to be in conduit.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

wrote in message
oups.com...
On Jul 6, 2:41?pm, (Doug Miller) wrote:
In article .com,
" wrote:





On Jul 6, 12:40?pm, (Doug Miller) wrote:
In article ,

wrote:
On Fri, 06 Jul 2007 11:55:17 GMT, (Doug Miller)
wrote:

No, it's not.

"A 6 AWG grounding electrode conductor that is free from exposure
to
physical
damage

Most inspectors say that is exposed to physical damage.

Perhaps -- but that's the inspector's call. The *Code* says 6 AWG
doesn't
necessarily have to be in conduit.
i ran a tiller into my service entrance cable, after the tiller hit a
rock.

spark city and could of easily died that day

What was your service entrance cable doing that close to the surface and
not
in conduit?

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.- Hide
quoted text -

- Show quoted text -

1950s home, all of them in the neighborhood that way. cable enters
high up on garage wall.......

oddly enough they replaced it the same way. but that was maybe 1980s.


That's just criminal!!!

i'd be more inclined to ask "why was your service entrance so close to your
garden?"

--
Steve Barker







"Doug Miller" wrote in message
t...

What was your service entrance cable doing that close to the surface and
not
in conduit?

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

Tom Horne

Well we aren't no thin blue heroes and yet we aren't no blackguards to.
We're just working men and woman most remarkable like you.

wrote:
On Fri, 6 Jul 2007 20:33:38 -0400, "RBM" rbm2(remove
wrote:

You are correct , but personally, I've never used smaller than #4 regardless
of service size. The difference in cost is minimal, and it eliminates the
possibility of an anal inspector giving you problems, or at least he has to
be more creative


This is the language they are working with.

(B) Securing and Protection from Physical Damage. A grounding
electrode conductor or its enclosure shall be securely fastened to the
surface on which it is carried. A 4 AWG copper or aluminum or larger
conductor shall be protected if exposed to severe physical damage. A 6
AWG grounding conductor that is free from exposure to physical damage
shall be permitted to be run along the surface of the building
construction without metal covering or protection where it is securely
fastened to the construction; otherwise, it shall be in rigid metal
conduit, intermediate metal conduit, rigid nonmetallic conduit,
electrical metallic tubing, or cable armor. Grounding conductors
smaller than 6 AWG shall be in rigid metal conduit, intermediate metal
conduit, rigid nonmetallic conduit, electrical metallic tubing, or
cable armor.


The "free from exposure to (any) physical damage" is what makes it
troubling for some inspectors. If a kid can touch it, it is exposed to
physical damage.

It is not your kid that most of them are concerned about it is your weed
eater or other powered garden or lawn maintenance equipment. By
personal experience I can tell you that schedule forty rigid nonmetallic
conduit is not adequate against weed eaters, trimmers, or edgers.
--
Tom Horne