Ground it to the home system.
I don't know the code details, but there is bare wire, known as "bonding
wire", that code requires run without any splices from the box to the actual
ground.

The important thing is that the ground be redundantly robust.
If there is a ground fault, a hot-to-ground leak in a powered appliance
would raise the potential of the chassis above ground.

Unlike neutral, which code says is to be bonded to ground at only one point,
it is considered good engineering practice to "grid the ground", meaning
multiple connections.

I would run an unspliced length of bonding wire from your box to the
generator.
Additional ground connections, such as a cold-water ground would provide
redundancy.



"Ignoramus24153" wrote in message
...
I am aware that "all generators must be grounded". In the instance of
a standby portable generator like this

http://igor.chudov.com/tmp/onan/Diesel/

how would I ground it? I have two options:

1. Ground it to a new grounding rod (expensive and involves actual
work).

2. Ground it to the home grounding system, such as copper pipes in the
utility room, or even better next to the existing home ground
connection.

Which option here is more legal and more safe?

thanks

i

"Ignoramus24153" wrote in message
...
I am aware that "all generators must be grounded". In the instance of
a standby portable generator like this

http://igor.chudov.com/tmp/onan/Diesel/

how would I ground it? I have two options:

1. Ground it to a new grounding rod (expensive and involves actual
work).

2. Ground it to the home grounding system, such as copper pipes in the
utility room, or even better next to the existing home ground
connection.

Which option here is more legal and more safe?

thanks

i

What does a grounding rod cost???

I bought some ground rod this spring, and I seem to recall that they were
about
$8 for an 8' length. It's a simple steel rod, sharpened point and coated
with copper.

I was surprised how inexpensive it was.


"Ignoramus24153" wrote in message
...
On Mon, 27 Dec 2004 17:55:16 GMT, Doug Kanter
wrote:

"Ignoramus24153" wrote in message
...
I am aware that "all generators must be grounded". In the instance of
a standby portable generator like this

http://igor.chudov.com/tmp/onan/Diesel/

how would I ground it? I have two options:

1. Ground it to a new grounding rod (expensive and involves actual
work).

2. Ground it to the home grounding system, such as copper pipes in the
utility room, or even better next to the existing home ground
connection.

Which option here is more legal and more safe?

thanks

i

What does a grounding rod cost???

I am not sure, I think that about $40, I may be mistaken. Plus, I have
to pound it in, it could bend, right now everything is frozen, etc etc
etc.

i

There are a couple of issues here.
Grounding the generator frame can be done via the Equipment Grounding Conductor
in the cable you connect it with (to the building electrode). Certainly driving
an additional rod when the ground thaws (~$10 plus about $5 worth of hardware)
is a safer approach but it will still have to be bonded back to the house via
the EGC.
The other issue is grounding the neutral. If your transfer equipment switches
the neutral you will need to ground the neutral in the generator.
In most cases the transfer switch only transfers the hot legs so you leave the
neutral isolated in the generator (as most portable generators are shipped).
This grounds the neutral via your main bonding jumper in the service panel.

Depending on how the generator will be used, it may not require a connection
to a grounding electrode system. The NEC states that it you will have
cord-and-plug connected equipment through the receptacles mounted on the
gen, then it doesn't require grounding of the frame. Also if this is the
case, then ensure that the manufacturer has bonded (connected) the neutral
and ground within the generator, as it is a separately derived source.
If the previous is not the case, then you must connect it to a grounding
electrode system. If your are serving a premises with a grounding electrode
system, it must be the same, meaning connect directly to it, or drive a rod
and connect the rod to the existing grounding electrode system. It must be
one grounding system, not isolated.

There are lots of other things to consider like how you will transfer the
loads to the gen, and such, but go carefully.

"Ignoramus24153" wrote in message
...
I am aware that "all generators must be grounded". In the instance of
a standby portable generator like this

http://igor.chudov.com/tmp/onan/Diesel/

how would I ground it? I have two options:

1. Ground it to a new grounding rod (expensive and involves actual
work).

2. Ground it to the home grounding system, such as copper pipes in the
utility room, or even better next to the existing home ground
connection.

Which option here is more legal and more safe?

thanks

i

Greg,
NEC-2002 250.34(C) that requires the neutral to ground bond only if the
generator is a separately derived source. It is only a separately derived
source if the neutral of the sources are switched. See 250.20(D) FPN No1

"Greg" wrote in message
...
There are a couple of issues here.
Grounding the generator frame can be done via the Equipment Grounding
Conductor
in the cable you connect it with (to the building electrode). Certainly
driving
an additional rod when the ground thaws (~$10 plus about $5 worth of
hardware)
is a safer approach but it will still have to be bonded back to the house
via
the EGC.
The other issue is grounding the neutral. If your transfer equipment
switches
the neutral you will need to ground the neutral in the generator.
In most cases the transfer switch only transfers the hot legs so you leave
the
neutral isolated in the generator (as most portable generators are
shipped).
This grounds the neutral via your main bonding jumper in the service
panel.

I bought 5/8" copper-clad steel ground rods for $8.xx earlier in the
year, but for the past couple of months or more they have been $13.xx at
the same store. The price of steel products has been skyrocketing,
allegedly because of the construction boom in China.

Perce


On 12/27/04 01:10 pm Bughunter tossed the following ingredients into the
ever-growing pot of cybersoup:

I bought some ground rod this spring, and I seem to recall that they were
about
$8 for an 8' length. It's a simple steel rod, sharpened point and coated
with copper.

I was surprised how inexpensive it was.

Ron and I agree. I was just trying to avoid some of the NEC speak that confuses
people. The point is you only want one bonding point between the neutral and
ground and if the transfer equipment doesn't switch neutral that will be the
jumper in your service panel.
(Separately derived source is NEC speak for a system where the neutral is
switched too so it will have separate bonding jumpers that go with the source).
All the frame grounding will be bonded, no matter what the transfer scheme.
Adding another electrode only insures that the ground on the case is more
closely referenced to the dirt under your feet when you are standing there.
Depending on where you live "ground shift" is more or less of a problem.
Here is the sandbox (Florida) I have seen 35 volt transients across 30-40 feet
between buildings.

You are connecting this to your home wiring with a transfer switch that
switches only the hot connection. Is that correct?

I used to have a link to a long article that went into extreme detail and
all that, but have misplaced it. Oh well. Anyhow...

If your generator ground is bonded to generator neutral, you MUST use a
transfer switch that switches both hot and neutral, and you MUST ground the
generator.

If your generator is not bonded (and no normally available generators are
bonded afaik, but your monster...) then you can switch only the hot and MUST
NOT ground the generator.

The article went on for pages about ground loops or somesuch thing (the
neutral being grounded in two different places). So, my suggestion is that
you find out if you can unbond your generator, since you are unlikely to
find a transfer switch to switch both hot and neutral. There is no need to
ground the generator separately, since it's ground is not connected to
anything except the house ground.

In article ,
"Robert Morein" wrote:

Ground it to the home system.
I don't know the code details, but there is bare wire, known as "bonding
wire", that code requires run without any splices from the box to the actual
ground.


That's right you don't know the code details so shouldn't be offering
advice.

I don't think that these rods are especially susceptible to corrosion.

I believe that the steel core is a standard feature. Yes, they look like
solid copper
but it's just a copper coating on the outside.

One of the rods in my home corroded and had to be replaced, but it took
nearly 30 years. I can handle $8 - $15 maintenance expense every 30 years
or so.
Life may be shorter if you have more acidic soil.

You can drive into pretty hard ground with a good sized sledge hammer, but
you are all done if you hit a hard rock. Lots of little firm taps works
better than
big swings, with less chance of bending the rod. Work slow until you get
most of the
rod into the ground, than you can take bigger swings.

NEC code has a spec for the amount of resistance
that you must shoot for, I think it was something like 8 ohms. I did not see
any
description of how you actually measure it. If you can't get it on the first
rod, you have to
drive in a second. But, even if you don't do any better with the second, you
can stop at two.
I guess they figure if you don't get it after driving two rods, you chances
of doing better
with several is slim.

There are other possibilities, including buried mesh screens, and even
attaching to rebar inside the concrete of the structure. Most of the other
methods require
a bit of pre-planning or more work to install.

If you buy steel cored copper rods, also pick up some heavy duty clamps
brass or copper
clamps that are made for this purpose to attach your ground wire to the rod.
Usually, you
use #6 braided copper with no insulator.



"Ignoramus24153" wrote in message
...
On Mon, 27 Dec 2004 18:10:22 GMT, Bughunter wrote:
I bought some ground rod this spring, and I seem to recall that they were
about
$8 for an 8' length. It's a simple steel rod, sharpened point and coated
with copper.

I was surprised how inexpensive it was.

This is nice. Steel, I am sure, does not bend as easily either.
Is there any issue with corrosion impeding conductivity?

i


"Ignoramus24153" wrote in message
...
On Mon, 27 Dec 2004 17:55:16 GMT, Doug Kanter

wrote:

"Ignoramus24153" wrote in message
...
I am aware that "all generators must be grounded". In the instance of
a standby portable generator like this

http://igor.chudov.com/tmp/onan/Diesel/

how would I ground it? I have two options:

1. Ground it to a new grounding rod (expensive and involves actual
work).

2. Ground it to the home grounding system, such as copper pipes in the
utility room, or even better next to the existing home ground
connection.

Which option here is more legal and more safe?

thanks

i

What does a grounding rod cost???

I am not sure, I think that about $40, I may be mistaken. Plus, I have
to pound it in, it could bend, right now everything is frozen, etc etc
etc.

i




--

On 27 Dec 2004 17:35:58 GMT, Ignoramus24153
wrote:

I am aware that "all generators must be grounded". In the instance of
a standby portable generator like this

http://igor.chudov.com/tmp/onan/Diesel/

how would I ground it? I have two options:

1. Ground it to a new grounding rod (expensive and involves actual
work).

2. Ground it to the home grounding system, such as copper pipes in the
utility room, or even better next to the existing home ground
connection.

Which option here is more legal and more safe?

thanks

i


I believe like any sub-panel, the ground must run back to the main
panel. Sorry that I can't remember what article this is in, maybe
someone else can help with that.

later,

tom @ www.Stuff4Free.biz

On 27 Dec 2004 18:00:27 GMT, Ignoramus24153
wrote:

On Mon, 27 Dec 2004 17:55:16 GMT, Doug Kanter wrote:

"Ignoramus24153" wrote in message
...
I am aware that "all generators must be grounded". In the instance of
a standby portable generator like this

http://igor.chudov.com/tmp/onan/Diesel/

how would I ground it? I have two options:

1. Ground it to a new grounding rod (expensive and involves actual
work).

2. Ground it to the home grounding system, such as copper pipes in the
utility room, or even better next to the existing home ground
connection.

Which option here is more legal and more safe?

thanks

i

What does a grounding rod cost???

I am not sure, I think that about $40, I may be mistaken. Plus, I have
to pound it in, it could bend, right now everything is frozen, etc etc
etc.

i


I heard a great tip for this. Use your hammer drill but on 'hammer
only'. Let the machine do the work.

hth,

tom @ www.FindMeShelter.com

On Mon, 27 Dec 2004 13:58:54 -0500, "Percival P. Cassidy"
wrote:

I bought 5/8" copper-clad steel ground rods for $8.xx earlier in the
year, but for the past couple of months or more they have been $13.xx at
the same store. The price of steel products has been skyrocketing,
allegedly because of the construction boom in China.

Don't forget the higher steel taxes the Unions had imposed on all
steel imports.


Perce


On 12/27/04 01:10 pm Bughunter tossed the following ingredients into the
ever-growing pot of cybersoup:

I bought some ground rod this spring, and I seem to recall that they were
about
$8 for an 8' length. It's a simple steel rod, sharpened point and coated
with copper.

I was surprised how inexpensive it was.

On Mon, 27 Dec 2004 18:01:23 -0500,
wrote:

On 27 Dec 2004 17:35:58 GMT, Ignoramus24153
wrote:

I am aware that "all generators must be grounded". In the instance of
a standby portable generator like this

http://igor.chudov.com/tmp/onan/Diesel/

how would I ground it? I have two options:

1. Ground it to a new grounding rod (expensive and involves actual
work).

2. Ground it to the home grounding system, such as copper pipes in the
utility room, or even better next to the existing home ground
connection.

Which option here is more legal and more safe?

thanks

i


I believe like any sub-panel, the ground must run back to the main
panel. Sorry that I can't remember what article this is in, maybe
someone else can help with that.

later,

tom @ www.Stuff4Free.biz

My reading of the pertinent section tells me that if the grounded
conductor is not switched, the generator equipment should be
seperately grounded. The NEC section on seperately derived systems is
not one I've spent a great deal of time with, however. In practice I
have a hard time understanding what problem could arise from
connecting the ground.

Dan

Our transfer switch switches both hots and the neutral.

Steve Spence
Dir., Green Trust
http://www.green-trust.org

toller wrote:
You are connecting this to your home wiring with a transfer switch that
switches only the hot connection. Is that correct?

I used to have a link to a long article that went into extreme detail and
all that, but have misplaced it. Oh well. Anyhow...

If your generator ground is bonded to generator neutral, you MUST use a
transfer switch that switches both hot and neutral, and you MUST ground the
generator.

If your generator is not bonded (and no normally available generators are
bonded afaik, but your monster...) then you can switch only the hot and MUST
NOT ground the generator.

The article went on for pages about ground loops or somesuch thing (the
neutral being grounded in two different places). So, my suggestion is that
you find out if you can unbond your generator, since you are unlikely to
find a transfer switch to switch both hot and neutral. There is no need to
ground the generator separately, since it's ground is not connected to
anything except the house ground.

"Steve Spence" wrote in message
...
Our transfer switch switches both hots and the neutral.

Steve Spence
Dir., Green Trust
http://www.green-trust.org

Actually I don't think it does. You change from mains to generator by
turning the mains breaker off and the generator breaker on. The neutral
doesn't have a switch on it that I saw.

NEC code has a spec for the amount of resistance
that you must shoot for, I think it was something like 8 ohms

25 ohms

If you can't get it on the first
rod, you have to
drive in a second.
....
I guess they figure if you don't get it after driving two rods, you chances
of doing better
with several is slim.

Exactly

There are other possibilities, including buried mesh screens,

1/4" 1 foot square copper plate (2 square feet counting both sides)

attaching to rebar inside the concrete of the structure.

Probably the best grounding electrode AKA a Ufer ground (H.George Ufer invented
it)

brass or copper
clamps

Bronze. May look like brass or copper at a quick glance

Usually, you
use #6 braided copper

Solid.

No, I don't touch the breaker box. I don't have a separate breaker for
the generator. I'm on inverter until I turn on the generator. the auto
transfer switch then switches the loads from inverter to generator.
There are two relays in the box, one switches the two hots, the other
switches the neutral. when the gen is shut off, it switches the loads
back to inverter.

you can see a picture of it at
http://www.green-trust.org/wiki/inde...olar_PV_System

Steve Spence
Dir., Green Trust
http://www.green-trust.org

toller wrote:
"Steve Spence" wrote in message
...

Our transfer switch switches both hots and the neutral.

Steve Spence
Dir., Green Trust
http://www.green-trust.org


Actually I don't think it does. You change from mains to generator by
turning the mains breaker off and the generator breaker on. The neutral
doesn't have a switch on it that I saw.

On Mon, 27 Dec 2004 22:57:03 GMT, "Bughunter" wrote:


You can drive into pretty hard ground with a good sized sledge hammer, but
you are all done if you hit a hard rock. Lots of little firm taps works
better than
big swings, with less chance of bending the rod. Work slow until you get
most of the
rod into the ground, than you can take bigger swings.

Even better
http://www.kencove.com/ShopDetail.ph...r&recordID=TPD

Fancy version above isn't required for only a few jobs... a piece of
pipe with a heavy multi-layered cap is fine for pounding ground rods,
at which point many electricians finish the job using a hack saw. :-)

Wayne

Our transfer switch switches both hots and the neutral.
Steve Spence
Dir., Green Trust
http://www.green-trust.org

Actually I don't think it does.

Some "alternate energy" systems are installed as separately derived sources so
they would use transfer equipment that switches the neutral. (perhaps as part
of protection for transients when the system is not connected to the building
ground)
On the other hand most "generator" transfer switches for portable generators
will not switch the neutral since the standard on portable generators is an
isolated ground. If used as a stand alone generator on a job site there is no
advantage to grounding the neutral, in fact it adds a hazard.
Fixed in place, pad mount generators can go either way. They will have a
grounding strap in the wiring compartment that you connect or disconnect,
depending on how you are installing them.
This whole deal can get pretty complicated to describe but the end objective is
to only have one point where ground and neutral is connected, no matter how the
system is switched.
When I am inspecting a complex system I have to draw it out sometimes to sort
out what is going on.

toller wrote:
"Steve Spence" wrote in message
...

Our transfer switch switches both hots and the neutral.

Steve Spence
Dir., Green Trust
http://www.green-trust.org


Actually I don't think it does. You change from mains to generator by
turning the mains breaker off and the generator breaker on. The neutral
doesn't have a switch on it that I saw.



Depends on the design of the transfer switch, I have one outside that is
set up for three phase and has four poles on the switch body.
Dave

Get a grounding rod and bang it into the earth, then, use the
appropriate connector to fasten 1/4" solid flexible copper to ; fasten
the other end to the generators ground connector. Thats exactly what im
about to do to my portable generator.

"Ignoramus24153" wrote in message
...
On Mon, 27 Dec 2004 12:49:39 -0500, Robert Morein
wrote:
Ground it to the home system.
I don't know the code details, but there is bare wire, known as "bonding
wire", that code requires run without any splices from the box to the
actual
ground.

The important thing is that the ground be redundantly robust.
If there is a ground fault, a hot-to-ground leak in a powered appliance
would raise the potential of the chassis above ground.

That ground connection should be faultless and super safe and
excessive, is a great point.

Unlike neutral, which code says is to be bonded to ground at only one
point,
it is considered good engineering practice to "grid the ground", meaning
multiple connections.

i am not so sure, myself, I remember reading otherwise.

That would be for the neutral.
What they don't permit is a second isolated ground:
See http://enginova.com/iso_ground.htm
The reason redundant grounds are permitted is because of lightning. The only
way to shield equipment in a building effectively is by grounding the
structure itself, to make a pseudo-Faraday cage.
A Faraday cage is simply a box with walls made of conducting material, so
that everything within is at the same potential.
In wood frame buildings, this is done by running ground wires all over the
place, with multiple connections. That way, if there is something
approaching a direct strike, every part of the building will remain at the
same potential, and the activities within will be unaffected.
See http://www.lightningsafety.com/nlsi_lhm/lpts.html
They do not endorse multiple ground rods. However, that is not part of the
NEC code.
This page advocates redundant grounds:
http://www.leminstruments.com/ground...ectrodes.shtml

I would run an unspliced length of bonding wire from your box to the
generator. Additional ground connections, such as a cold-water
ground would provide redundancy.

Thanks.

i



"Ignoramus24153" wrote in message
...
I am aware that "all generators must be grounded". In the instance of
a standby portable generator like this

http://igor.chudov.com/tmp/onan/Diesel/

how would I ground it? I have two options:

1. Ground it to a new grounding rod (expensive and involves actual
work).

2. Ground it to the home grounding system, such as copper pipes in the
utility room, or even better next to the existing home ground
connection.

Which option here is more legal and more safe?

thanks

i




--

"Ignoramus24153" wrote in message
...
On Mon, 27 Dec 2004 19:11:34 GMT, toller wrote:
[snip]

The article went on for pages about ground loops or somesuch thing (the
neutral being grounded in two different places). So, my suggestion is
that
you find out if you can unbond your generator, since you are unlikely to
find a transfer switch to switch both hot and neutral. There is no need
to
ground the generator separately, since it's ground is not connected to
anything except the house ground.

I will check and post updates. I am not sure just what possible
dangers to the generator could be created by unbonding.

I recently spoke to a professional electrician who confided that although
prohibited by the NEC, multiple hot-neutral bonds are quite common. He has
seen the question raised in professional meetings, and the answers were
always sketchy.

It seems that some electronic equipment is affected by noise impressed onto
ground, but the problem is overrated.

"Ignoramus24153" wrote in message
...
On Mon, 27 Dec 2004 23:32:14 -0500, Robert Morein
wrote:

"Ignoramus24153" wrote in message
...
On Mon, 27 Dec 2004 19:11:34 GMT, toller wrote:
[snip]

The article went on for pages about ground loops or somesuch thing
(the
neutral being grounded in two different places). So, my suggestion is
that
you find out if you can unbond your generator, since you are unlikely
to
find a transfer switch to switch both hot and neutral. There is no
need
to
ground the generator separately, since it's ground is not connected to
anything except the house ground.

I will check and post updates. I am not sure just what possible
dangers to the generator could be created by unbonding.

I recently spoke to a professional electrician who confided that although
prohibited by the NEC, multiple hot-neutral bonds are quite common. He
has
seen the question raised in professional meetings, and the answers were
always sketchy.

Hot-neutral bonds?????????????????

Any time turn something on you get a hot-neutral bond, though usually a high
resistance one.
Second hand information from a "professional electrician"... geez, when I
see some of the work done in the past on my house by professional; my 23a
water heater was run with #12 on a 30a breaker, a multiwire circuit was all
on the same leg, etc.

toller wrote:

Hot-neutral bonds?????????????????


Any time turn something on you get a hot-neutral bond, though usually a high
resistance one.
Second hand information from a "professional electrician"... geez, when I
see some of the work done in the past on my house by professional; my 23a
water heater was run with #12 on a 30a breaker, a multiwire circuit was all
on the same leg, etc.



A bond implies no -middle man- sort of load between two conductors.

The gentleman meant to say ground to neutral connections.

The guy doing your wiring should have been fired. A number twelve wire
suitable for house wiring is usually rated for 20 amps. Heating loads
have to use no more than 80 percent of the wire 'ampacity.

So, his number 12 was good for only 16 amps in this situation.

a 30 amp (#10) wire would have barely met the legal requirements (.8 X
30 = 24)


--
"The day Microsoft makes something that doesn't suck is
probably the day they start making vacuum cleaners."

Ernst Jan Plugge

"Ignoramus24153" wrote in message
...
On Mon, 27 Dec 2004 23:32:14 -0500, Robert Morein
wrote:

"Ignoramus24153" wrote in message
...
On Mon, 27 Dec 2004 19:11:34 GMT, toller wrote:
[snip]

The article went on for pages about ground loops or somesuch thing
(the
neutral being grounded in two different places). So, my suggestion
is
that
you find out if you can unbond your generator, since you are unlikely
to
find a transfer switch to switch both hot and neutral. There is no
need
to
ground the generator separately, since it's ground is not connected
to
anything except the house ground.

I will check and post updates. I am not sure just what possible
dangers to the generator could be created by unbonding.

I recently spoke to a professional electrician who confided that
although
prohibited by the NEC, multiple hot-neutral bonds are quite common. He
has
seen the question raised in professional meetings, and the answers were
always sketchy.

Hot-neutral bonds?????????????????

Oops!!!!

On Tue, 28 Dec 2004 05:32:06 GMT, m II
wrote:

toller wrote:

Hot-neutral bonds?????????????????


Any time turn something on you get a hot-neutral bond, though usually a high
resistance one.
Second hand information from a "professional electrician"... geez, when I
see some of the work done in the past on my house by professional; my 23a
water heater was run with #12 on a 30a breaker, a multiwire circuit was all
on the same leg, etc.



A bond implies no -middle man- sort of load between two conductors.

The gentleman meant to say ground to neutral connections.

The guy doing your wiring should have been fired. A number twelve wire
suitable for house wiring is usually rated for 20 amps. Heating loads
have to use no more than 80 percent of the wire 'ampacity.

So, his number 12 was good for only 16 amps in this situation.

a 30 amp (#10) wire would have barely met the legal requirements (.8 X
30 = 24)


I wonder if the water heater woudl be considered a 'continous load'
like a houses heating, but it does make sense even without the
derating, #12 shouldn't be used on a 30am breaker.

I'm guessing it was a typo.

later,

tom @ www.FindMeShelter.com

Ignoramus24153 wrote:
On Mon, 27 Dec 2004 23:32:14 -0500, Robert Morein wrote:

"Ignoramus24153" wrote in message
...

On Mon, 27 Dec 2004 19:11:34 GMT, toller wrote:

[snip]

The article went on for pages about ground loops or somesuch thing (the
neutral being grounded in two different places). So, my suggestion is

that

you find out if you can unbond your generator, since you are unlikely to
find a transfer switch to switch both hot and neutral. There is no need

to

ground the generator separately, since it's ground is not connected to
anything except the house ground.

I will check and post updates. I am not sure just what possible
dangers to the generator could be created by unbonding.


I recently spoke to a professional electrician who confided that although
prohibited by the NEC, multiple hot-neutral bonds are quite common. He has
seen the question raised in professional meetings, and the answers were
always sketchy.


Hot-neutral bonds?????????????????

i

I have done that many times, it's why I'm always buying new
screwdrivers. Quite a show when it happens :-(
Dave

I do not know exactly what the code says, but I do know what makes sense
from a safety perspective. The neutrals of all circuits should be
connected to ground at ONLY one place - in your main service panel. There
must be no grounding of neutrals in sub panels. Ranges etc. connected to
sub panel circuts should use a 4 pin connector (hot, hot, neutral, ground).

The ground wire from your main panel may be connected to multiple grounds
and it's best if these are close together. Two grounding rods are
frequently used for a lower resistance ground path and better reliability.

Do not ever use a pipe as a ground. The water supply line may be PVC or
may be changed to PVC at some time in the future and you would have no
ground.

Since a good ground is so important, use the gauge wire required by code or
larger, protect it where required and never allow a splice in it. Use only
the best quality U/L approved grounding clamps and be sure all contacting
surfaces are clean and tight.

All of this applies to your generator too. For best safety, if your
generator is outside, it should be physically close to your system ground.

If the code requires anything less, it should be changed.

I do not know exactly what the code says, but I do know what makes sense
from a safety perspective. The neutrals of all circuits should be
connected to ground at ONLY one place - in your main service panel. There
must be no grounding of neutrals in sub panels. Ranges etc. connected to
sub panel circuts should use a 4 pin connector (hot, hot, neutral, ground).

The ground wire from your main panel may be connected to multiple grounds
and it's best if these are close together. Two grounding rods are
frequently used for a lower resistance ground path and better reliability.

Do not ever use a pipe as a ground. The water supply line may be PVC or
may be changed to PVC at some time in the future and you would have no
ground.

Since a good ground is so important, use the gauge wire required by code or
larger, protect it where required and never allow a splice in it. Use only
the best quality U/L approved grounding clamps and be sure all contacting
surfaces are clean and tight.

All of this applies to your generator too. For best safety, if your
generator is outside, it should be physically close to your system ground.

If the code requires anything less, it should be changed.

wrote in message
...
On Tue, 28 Dec 2004 05:32:06 GMT, m II
wrote:

toller wrote:

Hot-neutral bonds?????????????????


Any time turn something on you get a hot-neutral bond, though usually a
high
resistance one.
Second hand information from a "professional electrician"... geez, when
I
see some of the work done in the past on my house by professional; my
23a
water heater was run with #12 on a 30a breaker, a multiwire circuit was
all
on the same leg, etc.



A bond implies no -middle man- sort of load between two conductors.

The gentleman meant to say ground to neutral connections.

The guy doing your wiring should have been fired. A number twelve wire
suitable for house wiring is usually rated for 20 amps. Heating loads
have to use no more than 80 percent of the wire 'ampacity.

So, his number 12 was good for only 16 amps in this situation.

a 30 amp (#10) wire would have barely met the legal requirements (.8 X
30 = 24)


I wonder if the water heater woudl be considered a 'continous load'
like a houses heating, but it does make sense even without the
derating, #12 shouldn't be used on a 30am breaker.

I'm guessing it was a typo.

No typo, stupidity. They also put three 20a circuits on a 50a breaker.
I replaced the #10 with #12, and put each 20a circuit on its own 20a
breaker.

wrote:
I do not know exactly what the code says, but I do know what makes sense
from a safety perspective. The neutrals of all circuits should be
connected to ground at ONLY one place - in your main service panel. There
must be no grounding of neutrals in sub panels. Ranges etc. connected to
sub panel circuts should use a 4 pin connector (hot, hot, neutral, ground).

The ground wire from your main panel may be connected to multiple grounds
and it's best if these are close together. Two grounding rods are
frequently used for a lower resistance ground path and better reliability.

Do not ever use a pipe as a ground. The water supply line may be PVC or
may be changed to PVC at some time in the future and you would have no
ground.

Since a good ground is so important, use the gauge wire required by code or
larger, protect it where required and never allow a splice in it. Use only
the best quality U/L approved grounding clamps and be sure all contacting
surfaces are clean and tight.

All of this applies to your generator too. For best safety, if your
generator is outside, it should be physically close to your system ground.

If the code requires anything less, it should be changed.

The US NEC requires that any underground water piping that is ten feet
or more in length shall be used as a grounding electrode. That is not
optional. No matter how authoritative a posting recomending against
this sounds it is bad advice for anyone who's work is governed by the US
NEC.

If the underground water piping were too short or non conductive the
code would require that any interior metal water piping that is likely
to become energized be bonded to the service equipment enclosure, the
grounded conductor at the service, the grounding electrode conductor
where of sufficient size, or to the one or more grounding electrodes
used. That connection is required regardless of whether there is any
underground metal water piping present. Most Authorities Having
Jurisdiction (AHJs) consider any metallic water piping that supplies
water to any electric appliance as likely to become energized and
although most AHJs will except the Equipment Grounding Conductor (EGC)
of the electrical equipment attached to the piping as the bonding means
for interior gas piping they will not except an EGC as the bonding means
for water piping. For water piping the bonding conductor must comply
with 250.104 of the US NEC which requires it to be sized exactly the
same as an Grounding Electrode Conductor (GEC).

[250.50 Grounding Electrode System.
If available on the premises at each building or structure served, each
item in 250.52(A)(1) through (A)(6) shall be bonded together to form the
grounding electrode system. Where none of these electrodes are
available, one or more of the electrodes specified in 250.52(A)(4)
through (A)(7) shall be installed and used.

250.52 Grounding Electrodes.
(A) Electrodes Permitted for Grounding.
(1) Metal Underground Water Pipe. A metal underground water pipe in
direct contact with the earth for 3.0 m (10 ft) or more (including any
metal well casing effectively bonded to the pipe) and electrically
continuous (or made electrically continuous by bonding around insulating
joints or insulating pipe) to the points of connection of the grounding
electrode conductor and the bonding conductors. Interior metal water
piping located more than 1.52 m (5 ft) from the point of entrance to the
building shall not be used as a part of the grounding electrode system
or as a conductor to interconnect electrodes that are part of the
grounding electrode system.

250.104 Bonding of Piping Systems and Exposed Structural Steel.
(A) Metal Water Piping. The metal water piping system shall be bonded as
required in (1), (2), (3), or (4) of this section. The bonding jumper(s)
shall be installed in accordance with 250.64(A), (B), and (E). The
points of attachment of the bonding jumper(s) shall be accessible.
(1) General. Metal water piping system(s) installed in or attached to a
building or structure shall be bonded to the service equipment
enclosure, the grounded conductor at the service, the grounding
electrode conductor where of sufficient size, or to the one or more
grounding electrodes used. The bonding jumper(s) shall be sized in
accordance with Table 250.66 except as permitted in 250.104(A)(2) and
(A)(3).] Copyright 2002 the National Fire Protection Association.

Failure to follow the electrical code that is enforced as law in your
area can void your fire and liabilty insurance if that failure results
in an otherwise insured loss. It is considered a legal obsurdity to
attempt to insure against the cosequences of the insureds own unlawful
act. Insurance contracts are "contracts of utmost good faith." That
means that all parties to the contract must scrupulously obey the law in
all matters that could affect any other party to that contract. To fail
to do so allows the other party to walk away from their obligation under
that contract if the failure to obey the law was the proximate cause of
the loss.
--
Tom H

In article ,
Ignoramus24153 wrote:

I believe that the neutral is bonded to the frame.

I also expect to have a transfer switch that will only switch hots.

i plan on having separate neutral and ground wires going from home to
the genset.

If the previous is not the case, then you must connect it to a grounding
electrode system. If your are serving a premises with a grounding
electrode
system, it must be the same, meaning connect directly to it, or drive a rod
and connect the rod to the existing grounding electrode system. It must be
one grounding system, not isolated.

There are lots of other things to consider like how you will transfer the
loads to the gen, and such, but go carefully.

That's exactly why I want to explore opinions and come up with a solid
plan. I do not want to have the generator grounded separately without need.

i


For my operations, I have all the gensets wired with the Neutral, Ground,
and both Hot Legs comming out as sperate wires. They then connect to
the Main Transfer Switch where both Hot Legs and Neutral, are switched.
The Neutral and Ground are Bonded at the MAIN 240Vac Panel, which is
where the Grounding Rod is also connected. At the 240/120Vac
Transformer, the Neutral on the 240Vac winding goes back to the Neutral
at the Main Panel, and one side of the 120Vac winding is brought to
the Neutral Buss in the 120Vac SubPanel, which is also Bonded to the
Ground Rod, to establish Neutral and ground for the secondary side
of the Transformer. One Breaker in the 120Vac SubPanel feeds the
Input to my 4024 Trace inverter, which then feeds the 120Vac Inverted
SubPanel, where the Neutral and Ground are not bonded. This is because
the Ground Connection on the Inverter is common to both Input and Output,
therefor the bonding in the 120Vac SubPanel sets the Ground on both
sides of the Inverter. The 120Vac Inverted SubPanel then feeds the
Cabin Subpanel, as well as the ToolShed and GenShed Circuits.


Bruce in alaska
--
add a 2 before @

I've seen this "IgnoramusXXXXX" stuff for years. What is the story?

toller wrote:


No typo, stupidity. They also put three 20a circuits on a 50a breaker.
I replaced the #10 with #12, and put each 20a circuit on its own 20a
breaker.


12 with 10..g





mike

"Ignoramus24153" wrote in message
...
On Mon, 27 Dec 2004 23:32:14 -0500, Robert Morein
wrote:

"Ignoramus24153" wrote in message
...
On Mon, 27 Dec 2004 19:11:34 GMT, toller wrote:
[snip]

The article went on for pages about ground loops or somesuch thing
(the
neutral being grounded in two different places). So, my suggestion
is
that
you find out if you can unbond your generator, since you are unlikely
to
find a transfer switch to switch both hot and neutral. There is no
need
to
ground the generator separately, since it's ground is not connected
to
anything except the house ground.

I will check and post updates. I am not sure just what possible
dangers to the generator could be created by unbonding.

I recently spoke to a professional electrician who confided that
although
prohibited by the NEC, multiple hot-neutral bonds are quite common. He
has
seen the question raised in professional meetings, and the answers were
always sketchy.

Hot-neutral bonds?????????????????

I am sure that he is referring to multiple bonding points to the neutral.
Your supposed to do it once at the service. The neutral is a "grounded
current carrying conductor" Having it grounded/bonded in more than one place
just increases the probability of something going wrong. Does it happen you
bet, is it correct. NO

If you ground to your service, best in my opinion. Use the same size ground
wire as your service. You are creating an "supplemental ground" for the
service. Any ground conductor smaller than the ground for the service could
create a weak link in the grounding. Bonding to the metallic piping systems
is required. This may not be a problem if you are able to come off of the
ground bar in the service. Assuming that the metallic piping systems are
bonded currently.

Personally I like and use only switched neutral transfer panels. Solid
neutral switches are available and a little cheaper. I have had to many
problems with sensitive electronics over the years. If my customer insists
then they find someone else to do the job. Almost all that have in the past
have come "crawling back" for me to fix it AFTER the damage was done. They
are very careful not to discuss or complain about price.
Having two sources of power is not rocket science. It is problematic when
incorrectly installed. If you land on a solid neutral block, you will have a
the possibility of current traveling to your generator while it is off.
Switching the neutral with the phases assures that the generator will be
completely isolated when not being used.

Ignoramus24153 wrote:

I am aware that "all generators must be grounded". In the instance of
a standby portable generator like this

http://igor.chudov.com/tmp/onan/Diesel/

how would I ground it? I have two options:

1. Ground it to a new grounding rod (expensive and involves actual
work).

2. Ground it to the home grounding system, such as copper pipes in the
utility room, or even better next to the existing home ground
connection.

Which option here is more legal and more safe?

This may help things..

http://www.cat.com/cda/components/se...language Id=7




--
"Build a man a fire, and he'll be warm for a day.
Set a man on fire, and he'll be warm for the rest of his life."

Terry Pratchett