Another subpanel grounding question
 

Hey all-

First off, I apologize for asking a question that seems to be asked
a lot around here. I've been reading posts on the subject for about 2
hrs this morning, but I'm missing something.

My situation: I have a main panel in my house, and I have an
attached garage which my dad and I put a 60amp subpanel in. Now I
know that I need to keep the neutral and ground separate in this
subpanel (I've seen LOTS on this topic), but what I'm missing is,
where do I connect the grounding bar in the subpanel? Grounding rod,
ground wire back to the main panel, don't need it?

Right now we've got (and I know our setup is wrong) the main lug
subpanel with just one bus bar, which is not connected to the case.
Both the ground and neutral wires for the branch circuits for this
panel are connected to this bar. We have two hot wires and one
neutral run back to the main panel where I have a 60amp breaker. The
inspector has been out and given the system his blessing (which makes
me doubt him a bit). My dad did most of the work, I had second
thoughts after the inspection, so that's why I'm here.

So to correct the situation, I presume I need to get a grounding bar
kit for the subpanel and hook the branch circuit grounds to it
(keeping the neutral isolated from the ground). But what do I hook
the grounding bar to? Do I need a grounding rod or a ground wire back
to the main panel?

Thank you in advance,
Korey

Another subpanel grounding question
 

You need a 4th wire back to the panel. It can be bare but the neutral must be
white insulated.

Another subpanel grounding question
 

Korey Atterberry wrote:
Hey all-

First off, I apologize for asking a question that seems to be asked
a lot around here. I've been reading posts on the subject for about 2
hrs this morning, but I'm missing something.

My situation: I have a main panel in my house, and I have an
attached garage which my dad and I put a 60amp subpanel in. Now I
know that I need to keep the neutral and ground separate in this
subpanel (I've seen LOTS on this topic), but what I'm missing is,
where do I connect the grounding bar in the subpanel? Grounding rod,
ground wire back to the main panel, don't need it?

Right now we've got (and I know our setup is wrong) the main lug
subpanel with just one bus bar, which is not connected to the case.
Both the ground and neutral wires for the branch circuits for this
panel are connected to this bar. We have two hot wires and one
neutral run back to the main panel where I have a 60amp breaker. The
inspector has been out and given the system his blessing (which makes
me doubt him a bit). My dad did most of the work, I had second
thoughts after the inspection, so that's why I'm here.

So to correct the situation, I presume I need to get a grounding bar
kit for the subpanel and hook the branch circuit grounds to it
(keeping the neutral isolated from the ground). But what do I hook
the grounding bar to? Do I need a grounding rod or a ground wire back
to the main panel?

Thank you in advance,
Korey

You have three wires from the service panel to the subpanel? Is the
neutral wire insulated? Is this a multiwire cable or individual wires
in conduit, or individual wires taped together in a bundle, or what?

Let's assume for a minute you have 2 black wires and a white or gray
wire. Run a bare or green wire back to the service panel, and if
possible run it with the old wires (but if you can't don't worry about
it.) Use this new wire for the ground and separate the grounds from the
neutrals in the subpanel. You'll probably need a grounding kit. Don't
forget to remove the bonding screw or strap that currently grounds your
neutral bar to the metal subpanel cabinet.

If you have 3 insulated black wires (or 2 blacks and a green), wrap
white tape around the ends of the neutral wire and proceed as above.

If you have 2 black wires and a bare wire, I'm not sure what the best
way to handle it is without seeing it. You need another insulated wire
for the neutral.

Bob

Another subpanel grounding question
 

in addition to what has been said, i believe code states that if your
garage/shop is in a seperate building, not only do you need to ground it
back to the panel in the house via a wire, but you need two grounding rods
sunk in the ground at the garage.

so in short, i think you need both if you want it to be 'correct'

randy

"Korey Atterberry" wrote in message
m...
Hey all-

First off, I apologize for asking a question that seems to be asked
a lot around here. I've been reading posts on the subject for about 2
hrs this morning, but I'm missing something.

My situation: I have a main panel in my house, and I have an
attached garage which my dad and I put a 60amp subpanel in. Now I
know that I need to keep the neutral and ground separate in this
subpanel (I've seen LOTS on this topic), but what I'm missing is,
where do I connect the grounding bar in the subpanel? Grounding rod,
ground wire back to the main panel, don't need it?

Right now we've got (and I know our setup is wrong) the main lug
subpanel with just one bus bar, which is not connected to the case.
Both the ground and neutral wires for the branch circuits for this
panel are connected to this bar. We have two hot wires and one
neutral run back to the main panel where I have a 60amp breaker. The
inspector has been out and given the system his blessing (which makes
me doubt him a bit). My dad did most of the work, I had second
thoughts after the inspection, so that's why I'm here.

So to correct the situation, I presume I need to get a grounding bar
kit for the subpanel and hook the branch circuit grounds to it
(keeping the neutral isolated from the ground). But what do I hook
the grounding bar to? Do I need a grounding rod or a ground wire back
to the main panel?

Thank you in advance,
Korey

Another subpanel grounding question
 

"Korey Atterberry" wrote in message
m...
Hey all-

First off, I apologize for asking a question that seems to be asked
a lot around here. I've been reading posts on the subject for about 2
hrs this morning, but I'm missing something.

My situation: I have a main panel in my house, and I have an
attached garage which my dad and I put a 60amp subpanel in. Now I
know that I need to keep the neutral and ground separate in this
subpanel (I've seen LOTS on this topic), but what I'm missing is,
where do I connect the grounding bar in the subpanel? Grounding rod,
ground wire back to the main panel, don't need it?

ground bars are attached to the can of the panel in the provided holes. The
neutral bar must be isolated from the can. Get a ground bar/insulated
neutral kit for the panel you bought.
You need to carry a code gauge ground wire from the service to the subpanel.
Driving an ground rod at the subpanel is allowed and is called a
supplemental ground. It must have a ground wire as large as the service has.
If you drive a ground rod and do not have a ground wire properly installed
you have created a ground loop. Not a good safe way to use electricity. But
then again there are a lot of people that choose this method.

Another subpanel grounding question
 

Another subpanel grounding question
 

xrongor wrote:
in addition to what has been said, i believe code states that if your
garage/shop is in a seperate building, not only do you need to ground it
back to the panel in the house via a wire, but you need two grounding rods
sunk in the ground at the garage.

so in short, i think you need both if you want it to be 'correct'

randy

"Korey Atterberry" wrote in message
m...

Hey all-

First off, I apologize for asking a question that seems to be asked
a lot around here. I've been reading posts on the subject for about 2
hrs this morning, but I'm missing something.

My situation: I have a main panel in my house, and I have an
attached garage which my dad and I put a 60amp subpanel in. Now I
know that I need to keep the neutral and ground separate in this
subpanel (I've seen LOTS on this topic), but what I'm missing is,
where do I connect the grounding bar in the subpanel? Grounding rod,
ground wire back to the main panel, don't need it?

Right now we've got (and I know our setup is wrong) the main lug
subpanel with just one bus bar, which is not connected to the case.
Both the ground and neutral wires for the branch circuits for this
panel are connected to this bar. We have two hot wires and one
neutral run back to the main panel where I have a 60amp breaker. The
inspector has been out and given the system his blessing (which makes
me doubt him a bit). My dad did most of the work, I had second
thoughts after the inspection, so that's why I'm here.

So to correct the situation, I presume I need to get a grounding bar
kit for the subpanel and hook the branch circuit grounds to it
(keeping the neutral isolated from the ground). But what do I hook
the grounding bar to? Do I need a grounding rod or a ground wire back
to the main panel?

Thank you in advance,
Korey



Actually, if the subpanel is in a separate building, you have the option
of *not* running 4 wires back to the main panel. There are restrictions
on this 3-wire method, of course. All this is moot because OP said it
was an attached garage.

Bob

Another subpanel grounding question
 

Thank you all for your help. To answer some questions and clarify, I
have an attached garage, and I ran three insulated black wires in the
trench. One wire we taped white to make a neutral. No other wires in
the trench. I now have the grounding bar I need for the subpanel.

Can anyone explain why I need to run the ground back to the main
panel, as opposed to sinking a couple of grounding rods outside near
the subpanel? These rods would be about 60-70 feet from the rods at
the main panel. Since the inspection is done I have mostly filled my
trenches, so adding another wire will be a chore, but I want to do the
right thing for safety (I guess meeting code is not as much of an
issue seeing as the original setup passed inspection...)

Another subpanel grounding question
 

Korey Atterberry wrote:

Thank you all for your help. To answer some questions and clarify, I
have an attached garage, and I ran three insulated black wires in the
trench. One wire we taped white to make a neutral. No other wires in
the trench. I now have the grounding bar I need for the subpanel.

Can anyone explain why I need to run the ground back to the main
panel, as opposed to sinking a couple of grounding rods outside near
the subpanel? These rods would be about 60-70 feet from the rods at
the main panel. Since the inspection is done I have mostly filled my
trenches, so adding another wire will be a chore, but I want to do the
right thing for safety (I guess meeting code is not as much of an
issue seeing as the original setup passed inspection...)

I would run a #8 green wire or a #6 bare wire back to the service panel
by whatever route was easiest -- just staple it to the studs and joists.
The ground wire is supposed to be run with the current-carrying
conductors, but there is an exemption for adding a ground to "old work."
#8 wire is easy to use but you're supposed to protect it from damage
with a conduit (but you could skip that if it's not gonna be inspected
and you promise to be careful never to abuse that wire ;-) #6 solid
wire is a bitch to work with, but it can legally be run without a conduit.

Bob

Another subpanel grounding question
 

Thank you to all who replied. Based on your advice I'm going to run
the #6 solid bare wire back to the main panel. I figure the #6 will
be easier to push up/down the short length of conduit from the ground
to the service elbow. I wish either myself, my dad, or the building
inspector would have caught the mistake earlier, since I have to
re-dig my trenches! Oh well, our clay was hard to dig the first time,
but at least it is also pretty hard to tamp well, so the digging will
go easier this time! I can't go through the house or garage since
it's all finished (which coincidentally is the same reason I needed
the subpanel in the first place).

Thanks again,
Korey