I would like to wire three 3-ways switches for various external lights
in my new detatched garage (switches in both house and garage). I just
laid the schedule 40 with 2-2-4AL (240vac power to garage with seperate
grounding rod) and pulled six 14g THHN black wires also. It was late
and I wasn't thinking about the fact that I need more wires for three
3-way switches.

I know there are several options for wiring 3way switches, some with
power to the light and others with power to the switch. Is one way
more preferable than the other? Also, when I pull additional 14g THHN,
should I use specific colors to meet code? Can I use one ground wire
between all 3 house switches? I need 4 wires per switch if I am
reading things right (hot, neutral, runner and ground).

Don't know why, but 3ways confuse me a bit and I want to make sure I am
doing it right.

Just looking for clarification...please don't post that I should hire
an licensed electrician.

Just a thought, but would it be possible to wire two 3-way switches
with the 6 wires I have already? and still be acceptable to NEC?

wrote:

I would like to wire three 3-ways switches for various external lights
in my new detatched garage (switches in both house and garage). I just
laid the schedule 40 with 2-2-4AL (240vac power to garage with seperate
grounding rod) and pulled six 14g THHN black wires also. It was late
and I wasn't thinking about the fact that I need more wires for three
3-way switches.

I know there are several options for wiring 3way switches, some with
power to the light and others with power to the switch. Is one way
more preferable than the other? Also, when I pull additional 14g THHN,
should I use specific colors to meet code? Can I use one ground wire
between all 3 house switches? I need 4 wires per switch if I am
reading things right (hot, neutral, runner and ground).

Don't know why, but 3ways confuse me a bit and I want to make sure I am
doing it right.

Just looking for clarification...please don't post that I should hire
an licensed electrician.


You can do it with the existing 6 conductors.
The 3 switches in the house will be SPST type and will
feed 120V to 3 of the conductors. In the garage these
conductors connect to 3 120V AC relays which are SPDT.
The relay contacts act as the 3W switch.

To keep everyone happy, the relays will be UL-listed
for the purpose and have NEMA1 enclosure(s).
(Ask if a separate disconnecting means for each
of the live conductors will be req'd at the garage.)

So......you need these wires:
Neutral
Hot (always)
3 Signal wires to relays
Equip Ground (Green)

Total: 6

Just for grins, the number could be further reduced,
but 6 will do it.

Jim

wrote:

I would like to wire three 3-ways switches for various external lights
in my new detatched garage (switches in both house and garage). I just
laid the schedule 40 with 2-2-4AL (240vac power to garage with seperate
grounding rod) and pulled six 14g THHN black wires also. It was late
and I wasn't thinking about the fact that I need more wires for three
3-way switches.

I know there are several options for wiring 3way switches, some with
power to the light and others with power to the switch. Is one way
more preferable than the other? Also, when I pull additional 14g THHN,
should I use specific colors to meet code? Can I use one ground wire
between all 3 house switches? I need 4 wires per switch if I am
reading things right (hot, neutral, runner and ground).

Don't know why, but 3ways confuse me a bit and I want to make sure I am
doing it right.

Just looking for clarification...please don't post that I should hire
an licensed electrician.



Yes, there's a reliable way of controlling three external lights on the
garage from three switches in the house and three switches in the
garage, assuming the lights are reasonably sized, like not over 500
watts each.

But, the amount of work and materials needed may be more trouble than
your just pulling the needed extra wires.

***************************

Here goes:

Buy three single pole 10A contact 120 vac coil "impulse stepping relays"
like the ones shown he

http://www.relayserviceco.com/relay3.htm

mount them in an enclosure in the garage.

use two of the six 14 gage wires to bring a 120 volt hot, neutral and
ground to the garage. (One side of the 240 in the garage is probably
going to be at the same potential as a separate 120 volt hot, but I'd be
more comfortable using a separate wire.)

Power the three lights from that circuit, through the contacts of each
of the three relays.

Install three normally open pushbutton switches in the house and wire
them so they put 120 volts on each of the three remaining wires when
they are pushed.

Connect those three wires to the coils of the three relays, the other
ends of the coils are connected to neutral.

Install three normally open pushbutton switches in the garage and use
them to also put 120 volts on on the coils of the three relays. (They
will be electrically in parallel with the switches in the house.)

To turn a light on or off, just push the appropriate button, and the
relay will "alternate" and do the job, just like pulling on the string
of an overhead "on-off" fixture.

***********************

I'm presuming you can see the lights from both the house and the garage
switch locations, but if you can't, you're no worse off than if you
wired them with conventional three way switches, 'cause they don't give
you an indication of whether the controlled light is on or off either
unless you add more wires and pilot lamps. G

***********************

If you want a more expensive space age solution, I'm sure you can
accomplish the job with X-10 equipment where you'd only have to use
three of those wires to bring a 120 vac hot, neutral and ground to the
garage.

HTH,

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

Wow, those are some creative ways. Thanks, but I think I will resort
to pulling additional wires. So now, I will need what? 1 ground that
I can share? and 3 runners? Should I pull 1 green and 3 reds? or does
it matter. I have a lot of 14g black THHN, so I could still use that
if that is ok.

Also, my schedule40 is 1.5" wide and has 2 90degree and 1 45degree
bends and is about 50ft in length (carrying 2-2-4AL URD and 6 14g
THHN). Should I try to do this with a nylon fish? or use one of the
existing 14g THHN wires to pull the additional wires...will the 14 hold
up for this?

wrote:
I would like to wire three 3-ways switches for various external lights
in my new detatched garage (switches in both house and garage). I
just laid the schedule 40 with 2-2-4AL (240vac power to garage with
seperate grounding rod) and pulled six 14g THHN black wires also. It
was late and I wasn't thinking about the fact that I need more wires
for three 3-way switches.

I know there are several options for wiring 3way switches, some with
power to the light and others with power to the switch. Is one way
more preferable than the other? Also, when I pull additional 14g
THHN, should I use specific colors to meet code? Can I use one
ground wire between all 3 house switches? I need 4 wires per switch
if I am reading things right (hot, neutral, runner and ground).

Don't know why, but 3ways confuse me a bit and I want to make sure I
am doing it right.

Just looking for clarification...please don't post that I should hire
an licensed electrician.

Why not just use X-10 technology.

Take a look at:

http://www.smarthome.com/index.html

--
Joseph Meehan

Dia duit

Yes, I would agree, use X-10.
You are talking two or three control locations for under eight
lights/appliances. When you research X-10 a little bit, you will see
that it has huge advantages.

Now if you were talking about controlling 20 lights from 5 controllers
with remote control and timers and computer control, I'd say avoid X-10
like the plague, but for your installation, you will love it.

According to :
Wow, those are some creative ways. Thanks, but I think I will resort
to pulling additional wires. So now, I will need what? 1 ground that
I can share? and 3 runners? Should I pull 1 green and 3 reds? or does
it matter. I have a lot of 14g black THHN, so I could still use that
if that is ok.

If you're doing three "classic" sets of three-way switches (6 switches
in total switching three loads): Each pair of switches need 3 wires
that will be hot/switched hot. Plus a ground (green) and a possibly
a neutral (white, if the load is at the other end of the conduit from
the unswitched power feed you need a white wire).

All black is okay for the hot/switched hot, but one red per switch pair
may make things a little simpler to puzzle out when you're wiring.

Also, my schedule40 is 1.5" wide and has 2 90degree and 1 45degree
bends and is about 50ft in length (carrying 2-2-4AL URD and 6 14g
THHN). Should I try to do this with a nylon fish? or use one of the
existing 14g THHN wires to pull the additional wires...will the 14 hold
up for this?

Using one of the existing wires to pull the others would probably
work best. Especially if it's stranded.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

wrote in message
oups.com...
I would like to wire three 3-ways switches for various external lights
in my new detatched garage (switches in both house and garage). I just
laid the schedule 40 with
please don't post that I should hire
an licensed electrician.
and pulled six 14g THHN black wires also. It was late
and I wasn't thinking about the fact that I need more wires for three
3-way switches.

I know there are several options for wiring 3way switches, some with
power to the light and others with power to the switch. Is one way
more preferable than the other? Also, when I pull additional 14g THHN,
should I use specific colors to meet code? Can I use one ground wire
between all 3 house switches? I need 4 wires per switch if I am
reading things right (hot, neutral, runner and ground).

Don't know why, but 3ways confuse me a bit and I want to make sure I am
doing it right.

Just looking for clarification...please don't post that I should hire
an licensed electrician.


please don't post that I should hire an licensed electrician. YOU NEED ONE

"2-2-4AL (240vac power to garage with separate grounding rod)"
A separate ground rod is a violation of the electrical Code. What you need
is another conductor for the ground. What you have created is commonly
called a ground loop. Your installation will use the earth as a return path
for a fault in the garage, not good practice nor code complaint.

if all you wanted was 2 3 ways the 6 #14's would be enough to make 2-3way
switches work.

I would like to wire three 3-ways switches for various external lights
in my new detatched garage (switches in both house and garage). I just
laid the schedule 40 with 2-2-4AL (240vac power to garage with seperate
grounding rod) and pulled six 14g THHN black wires also. It was late
and I wasn't thinking about the fact that I need more wires for three
3-way switches.

Just looking for clarification...please don't post that I should hire
an licensed electrician.

THHN isn't permitted for underground use. Article 300.5 requires that all
cables & conductors installed underground in metal or plastic conduit be
listed for wet locations. You should use THW or similar. Also, article
300.50 requires that the PVC conduit be protected with 3" of concrete. Also
be aware that you are limited to a 40% conduit fill with these conductors.
(Just guessing but you should be up around a 2" to 2-1/2" conduit.)

As for the entrance, if this is being wired into your existing service, you
MUST run a 4-wire feeder to the garage, and NO grounding rod (Article
250.24(A)(5) "no grounding connections on the load side of the service). If
this is wired directly to the pole with a meter base, your Ok with the
3-wire installation & grounded service. (If you are running a service
entrance, your local utility will not connect this unless you have a
building permit posted and the final hookup is done by a licensed
electrician (usually- in most parts of the country.)

Also remember that all receptacles installed in the garage must be protected
by a GFCI's.

As far as your question, if these 15 amp circuits are connected into your
existing service, you have six conductors running to the garage. You need
two conductors for each 3-way circuit.

Here's how to wire 3-way branch circuits. As you have 6 conductors, you can
have three 3-way circuits (but you will still need to pull 3 more conductors
for the grounds on these circuits (colored white). Basically, three cables
of 14/3 w/ground, are what's required.

-----------------------(grounded wire - white) ------------|
house garage
|
|---- (black) ---------|
(L)
--------15a------(S) (S)----------------|
|---- (black) ---------|
(S)- 3-way switch
(L)- light

Now, not forgetting what you said, I still strongly recommend you hire a
licensed electrician to AT LEAST look over the final installation and make
the final connection (to power.) This would not amount to a lot of bucks and
would be the best money you could spend in the entire project. The reason I
harp on this is, based on the questions you are asking, I feel that you know
just enough about wiring to be dangerous. Not meant to be an insult, just
feel that what your doing could be dangerous in the long run.

You also need to get a building permit. I assume you didn't bother with one
as the AHJ (Local Electrical Inspector) would have probably made you submit
a feeder diagram and would have nixed your plans right then and there. If
you don't,the AHJ could discover this construction during the next
assessment and you could end up paying an electrician to re-wire it and have
additional fines and fees to pay then. Also remember that if you ever sell
the home, your still responsible forever should a problem develop. The new
owners insurance company will come back on you (or your estate.)

Actually, a separate grounding rod IS acceptable per NEC as long as
there are no gas or metal water pipes shared between the buildings.
You don't bond the bus on the subpanel...so no loop.

"if all you wanted was 2 3 ways the 6 #14's would be enough to make
2-3way
switches work. " I don't think this is right either...each switch
would require hot, switched hot, neutral and ground. even for 2
switches, that's 7 wires even if you share the ground. Thanks for
posting a response though.

No insult taken, I posted to learn. Your right on the THWN, and most
THHN is also rated as THWN (which mine is). Interestingly I do have a
building permit and the electrical inspector is the one who showed me
the code on being able to run 2-2-4AL with a grounding rod at the
garage. My original intent was 2-2-2-4AL, but he convinced me
otherwise and showed me the code which supported it (no metal pipes
shared between buildings)

I could be mistaken, but you mentioned the ground wire should be white?
I thought that it should always be green if possible.?

wrote:
No insult taken, I posted to learn. Your right on the THWN, and most
THHN is also rated as THWN (which mine is). Interestingly I do have a
building permit and the electrical inspector is the one who showed me
the code on being able to run 2-2-4AL with a grounding rod at the
garage. My original intent was 2-2-2-4AL, but he convinced me
otherwise and showed me the code which supported it (no metal pipes
shared between buildings)

I could be mistaken, but you mentioned the ground wire should be white?
I thought that it should always be green if possible.?


I'm sure your inspector meant well but the prohibition against other
metallic pathways between the two buildings includes those lighting
switch circuits or any other wiring besides the feeder itself. If you
run a ground with your switching circuits it will end up carrying
neutral current in parallel with the neutral of the feeder. If you
don't run a ground with the switching circuits you will have a poor
fault clearing pathway for those circuits because the Equipment
Grounding Conductors (EGCs) for the garage will be bonded at the
building disconnecting means to the neutral of the garage feeder and the
EGCs for the house are bonded to the neutral of the power company supply
at the service disconnecting means for the entire premise. That may
make for an excessively long fault path. You would also never be able
to run an extension telephone, intercom, alarm circuit, video cable, nor
any other conductive pathway between the garage and the house. In order
to have a fully safe and efficient system to supply power to your garage
I'd suggest that you run a separate EGC in the feeder and use it to
provide the fault clearing pathway for all of the garage's wiring.
--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
for general use." Thomas Alva Edison

Hmmmm....interesting.

Help me understand what the risk is if I run a ground for the switches
to the garage? I don't forsee any need to run phone, alarm, etc.
When you say separate EGC do you mean another run of #2 AL to ground to
the house ground?

To have 3 switches control one circuit of lamp(s), it's easy to do
with a 24 V (or other) coil bi-stable latching (or toggle) relay. The 3
switches are just pushbuttons. Momentarily pressing of a button will
put the relay in the opposite state that it is in currently. In other
words, If the light is on, press a button and the light will turn off.
If the light is off, press a button and the light will turn on.

If you use the low voltage control circuit, you won't need 14 gauge
wire. And with a relay, you can have as many buttons as you want -
not just 3.

I paid $32 for that kind of relay about a year ago from
http://eskc.com/default.asp . A quick web search didn't turn up
anything that cheap currently, but you would look harder (use the phone
too), or maybe pay more.

You could use some electronics to do the job too:
http://ourworld.compuserve.com/homep...page9.htm#4013

--
)|__ Nehmo __):|(
--

wrote in message
oups.com...
I would like to wire three 3-ways switches for various external lights
in my new detatched garage (switches in both house and garage). I just
laid the schedule 40 with 2-2-4AL (240vac power to garage with seperate
grounding rod) and pulled six 14g THHN black wires also. It was late
and I wasn't thinking about the fact that I need more wires for three
3-way switches.

I know there are several options for wiring 3way switches, some with
power to the light and others with power to the switch. Is one way
more preferable than the other? Also, when I pull additional 14g THHN,
should I use specific colors to meet code? Can I use one ground wire
between all 3 house switches? I need 4 wires per switch if I am
reading things right (hot, neutral, runner and ground).

Don't know why, but 3ways confuse me a bit and I want to make sure I am
doing it right.

Just looking for clarification...please don't post that I should hire
an licensed electrician.


Hire an unlicensed electrician?

So I am using the ground from the house instead of the garage? No
issues with that?

The load is in the garage. This sounds like it might work for me...any
NEC issues?

On 30 Nov 2005 06:51:05 -0800, wrote:

So I am using the ground from the house instead of the garage? No
issues with that?

The load is in the garage. This sounds like it might work for me...any
NEC issues?


Reguardless of where you end up grounding, you can drive the switches
with seven insulated conductors, and one bare/green, for a total of
8 wires between buildings.

See www.goedjn.com/sketch/3x3.gif for a schematic.

If the supply line originates in the house, use the top
layout, with the one nuetral(white). If the supply line
originates in the garage, use the bottom layout, in which
case that last conductor becomes a supply line, and
should be colored.

If the three switches in the house are in different boxes,
then you'll end up with a useless white wire between the
three switch-boxes.

--Goedjn

wrote:

Actually, a separate grounding rod IS acceptable per NEC as long as
there are no gas or metal water pipes shared between the buildings.
You don't bond the bus on the subpanel...so no loop.


In this configuration you do bond the neutral/garage-ground/ground-rod.

I would follow the advice of if using the #14s. I
havn't looked at X-10, an interesting idea, but my understanding is it
uses signals imposed on power wires and could use the feeder wiring with
no use of the 14s. I agree with Tom Horne that you can't include #14
grounds.

bud--

Thanks for the correction. I guess I'm a little confused. What are
the issues is I use #14 ground to the garage vs. #14 ground to the
house?

wrote:
Hmmmm....interesting.

Help me understand what the risk is if I run a ground for the switches
to the garage? I don't forsee any need to run phone, alarm, etc.
When you say separate EGC do you mean another run of #2 AL to ground to
the house ground?


When you run a separate EGC to the garage it will be in parallel with
the neutral of the feeder because the code requires it to be bonded to
the neutral at both buildings disconnecting means. That means it will
carry a portion of the neutral current during normal operating
conditions. If anything then happened to the continuity of the feeder
neutral the EGC will carry the neutral current at a very high voltage
drop until it fails open. With either a high voltage drop or an open
circuit the voltage of all exposed metallic portions of the electrical
system and any conductive surface in contact with it will rise to 120
volts relative to the earth or such grounded conductive surfaces as the
garage floor.

I am a firefighter / EMT and I have run a call were such a condition
killed the user. Yes it's rare but it does happen. Since such
incidents are rarely investigated when they occur in a non work setting
the number of such incidents is undoubtedly higher than is currently
known.
--
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:
So I am using the ground from the house instead of the garage? No
issues with that?

The load is in the garage. This sounds like it might work for me...any
NEC issues?


Yes that is exactly the type of parallel pathway that the code forbids
for three wire feeders. Your switching circuits do count as another
metallic pathway.

If you run all portions of the garage end of the circuit in non metallic
raceway, use all nonmetallic boxes and cover plates, and install only
non metallic lighting fixtures it might be reasonably safe. The moment
one of the non metallic switch plates or fixtures is replaced with one
that has exposed metal then your single layer of safety is gone. You
would also have to violate the code requirement that the EGCs in the
garage should be bonded to the neutral of the feeder at the building
disconnecting means.

You can use X10 controls via the feeder without violating the code.
Wireless three way switches that use radio signals to control the switch
at the light would also work.
--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
for general use." Thomas Alva Edison

On 29 Nov 2005 11:27:50 -0800, wrote:

I would like to wire three 3-ways switches for various external lights
in my new detatched garage (switches in both house and garage). I just
laid the schedule 40 with 2-2-4AL (240vac power to garage with seperate
grounding rod) and pulled six 14g THHN black wires also. It was late
and I wasn't thinking about the fact that I need more wires for three
3-way switches.

You do? Why7 IIUC, you don't want 3 pairs of 3-ways, you just want
three switches to control some lights in the garage.

I presume you want one switch in the house and one in the garage.
Where do you want the third switch?

It doesn't really matter.

When you go above two 3-way swtiches, the rest of them have to be
4-way switches. Electrically, the 4-ways have to all be between the
three-ways that are at the end.

Between each pair of switches you need 2 hot wires, only one of which
will be hot at any given moment. Plus a neutral wire. Plua the
uninsulated ground that comes inside BX, for example.

I know there are several options for wiring 3way switches, some with
power to the light and others with power to the switch. Is one way
more preferable than the other? Also, when I pull additional 14g THHN,
should I use specific colors to meet code? Can I use one ground wire
between all 3 house switches?

Yes.

I need 4 wires per switch if I am
reading things right (hot, neutral, runner and ground).

I don'tt know what you mean "per switch". You need 4 wires AT each
switch, but in most ways of looking at things, they are the same 4
wires. Two are the neutral and ground -- two wires come in and two
wires go out, usually spliced witha wire nut.

In addition, for the first 3-way switch one wire goes in and two go
out. For the second 3-way, two wires go in and one wire goes out.
And for all the 4-ways in between, 2 wires go in and 2 wires go out.

This may sound like 8 wires, but 4 are going back to the previous
switch and 4 are going on to the next switch.. You only need four
wires, and some places only 3.

No relays, no X-10 needed imo.

Don't know why, but 3ways confuse me a bit and I want to make sure I am
doing it right.

Just looking for clarification...please don't post that I should hire
an licensed electrician.


Remove NOPSAM to email me. Please let
me know if you have posted also.

On Wed, 30 Nov 2005 11:38:30 -0600, Bud--
wrote:

wrote:

Actually, a separate grounding rod IS acceptable per NEC as long as
there are no gas or metal water pipes shared between the buildings.
You don't bond the bus on the subpanel...so no loop.


In this configuration you do bond the neutral/garage-ground/ground-rod.

I would follow the advice of if using the #14s. I
havn't looked at X-10, an interesting idea, but my understanding is it
uses signals imposed on power wires and could use the feeder wiring with
no use of the 14s. I agree with Tom Horne that you can't include #14
grounds.

bud--

X10 devices use a 121KHz signal sent over the power line. A burst is
sent at each zero-crossing (so obviously, X10 requires AC power). No
additional wiring is required. X10 commands are slow, about 1/3 second
per command. A simple operation usually takes 2 commands. one to
select the device and the other to operate the selected device.

One good thing about X10, is that it uses separate ON and OFF commands
(rather than just a toggle). This is useful (or even essential)
sometimes.

Wireless X10 controllers exist (with the decreased reliability of
wireless). It's best to avoid them if you have (or can add) wires to
the control locations (the simplest and least expensive X10 controller
is an 8-device unit that can be plugged into any outlet using the same
power transformer as the devices to be controlled).

Note that there will be a unit code (1-16) and house code (A-P)
allowing up to 256 addressable devices. The controller can only be set
to one house code (it's best to avoid A since that's the default). You
could use G1, G2, G3, and G4.
--
25 days until the winter solstice celebration

Mark Lloyd
http://notstupid.laughingsquid.com

"Democracy is two wolves and a lamb voting on what
to have for lunch. Liberty is a well armed lamb
contesting the vote." - Benjamin Franklin

I could be mistaken, but you mentioned the ground wire should be white?
I thought that it should always be green if possible.?

The "grounded" conductor (mistakeningly called a neutral in a 120 volt
circuit) is colored white, the "grounding" (or bonding) conductor is green.

wrote:
Thanks for the correction. I guess I'm a little confused. What are
the issues is I use #14 ground to the garage vs. #14 ground to the
house?

I'm not sure what you are asking. You can't run a #14 ground from house
to garage as this would be a "separate metalic path" which is prohibited
if you run only a neutral (without a ground) as the supply in your
feeder. A #14 ground from house to garage would appear in parallel with
the neutral. The grounds at the garage are picked up from the common
neutral/grounding-electrode.

bud--

wrote:

Hmmmm....interesting.

Help me understand what the risk is if I run a ground for the switches
to the garage? I don't forsee any need to run phone, alarm, etc.
When you say separate EGC do you mean another run of #2 AL to ground to
the house ground?


You ran a feeder with 2 hots, a neutral and no ground. The other option
is to run include a ground. The ground wire is sized from a table and
would likely be smaller than #2, I'm too lazy to look it up. The ground
wire from the house is connected to the ground wires in the garage
(ground bar) and the grounding electrode (usually ground rod). The
difference is that the neutral bar is isolated from the garage ground
system. If you wired the garage this way you don't need #14 grounds from
the house to the garage because the feeder ground is sufficient.

I have a very rare disagreement with Tom Horne, who puts up very good
posts. The fault clearing path as you are wiring the garage is via the
feeder neutral. If you ran a separate ground wire with the feeder, the
fault clearing path would be through the likely smaller feeder ground
wire. I don't see how that is an advantage.

I assume there is only one Tom Horne and you just changed hats?

bud--

OK, let me restate, cause I think I am finally getting it.

for my light fixture in the garage, the neutral (white wire) stays in
the garage. It is the Hot/Switched Hot/Runner (3 wires) that goes to
the House 3way and then to the garage 3way. I got that.

If I run a #14green wire from the garage to the house as an EGC ground
(just for the switch which is in non-metalic switchbox)...I have
violated code?

If I run the green ground wire from the house side switch to the house
EGC, and keep the garage side switch grounded to the garage, would this
allow me to keep the grounds separate and not violate code/be unsafe?

I'm trying to figure out my options short of running another #4AL
feeder cable for the ground. I can pull more #14 wires, but just need
to know how I can make this code compliant and safe.

Thanks!

I'm trying to figure out my options short of running another #4AL
feeder cable for the ground. I can pull more #14 wires, but just need
to know how I can make this code compliant and safe.


I don't think you can. You have two mutually exclusive choices:

1: Supply power to the garage with two hot wires, and a combined
ground/nuetral connected to earth in the garage.

and

2: Have switches in the house that are electrically connected to
something in the garage.

I'm pretty sure you're not allowed to do both.
SO you have to either figure out how to control the
garage lights with a remote, or run a 4-wire feeder
cable to the garage, and abandon the local ground.

I don't have the NEC, but my understanding is that 225.30(d) allows an
exception for outside lighting to be controlled from multiple locations
is permitted. I'm not clear though if what I want to do falls within
that. Either way since it is detached, I must have the local ground
even with a 4 wire feeder, just would keep the neutral and EGC seperate
in that case. (i think)

Goedjn wrote:
I'm trying to figure out my options short of running another #4AL
feeder cable for the ground. I can pull more #14 wires, but just need
to know how I can make this code compliant and safe.



I don't think you can. You have two mutually exclusive choices:

1: Supply power to the garage with two hot wires, and a combined
ground/nuetral connected to earth in the garage.

and

2: Have switches in the house that are electrically connected to
something in the garage.

I'm pretty sure you're not allowed to do both.
SO you have to either figure out how to control the
garage lights with a remote, or run a 4-wire feeder
cable to the garage, and abandon the local ground.

No you do not "abandon the local ground"! The grounding electrode
system is required in either case whether the feeder has an Equipment
Grounding Conductor (EGC) run with it or not. In a three wire feeder
the neutral of the feeder is bonded to the grounding electrode system of
the garage at the building disconnecting means. With a four wire feeder
that includes an EGC The EGC is bonded to the grounding electrode system
at the building disconnecting means and the neutral is kept aloof from
ground in the garage so that the neutral current will not flow on the
parallel conductive pathways to the building in which the service is
located.
--
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.

Bud-- wrote:
wrote:

Hmmmm....interesting.

Help me understand what the risk is if I run a ground for the switches
to the garage? I don't forsee any need to run phone, alarm, etc.
When you say separate EGC do you mean another run of #2 AL to ground to
the house ground?


You ran a feeder with 2 hots, a neutral and no ground. The other option
is to run include a ground. The ground wire is sized from a table and
would likely be smaller than #2, I'm too lazy to look it up. The ground
wire from the house is connected to the ground wires in the garage
(ground bar) and the grounding electrode (usually ground rod). The
difference is that the neutral bar is isolated from the garage ground
system. If you wired the garage this way you don't need #14 grounds from
the house to the garage because the feeder ground is sufficient.

I have a very rare disagreement with Tom Horne, who puts up very good
posts. The fault clearing path as you are wiring the garage is via the
feeder neutral. If you ran a separate ground wire with the feeder, the
fault clearing path would be through the likely smaller feeder ground
wire. I don't see how that is an advantage.

I assume there is only one Tom Horne and you just changed hats?

bud--

Perhaps I was not clear. If the fault clearing path is via the feeder's
neutral it would be because the Equipment Grounding Conductors (EGCs)
are connected to the main bonding jumper at both buildings. Between the
main bonding jumper and the switch boxes the EGC would not be in the
same raceway or cable as the current carrying conductors for the
circuit. Such divergent pathways always have a higher impedance then
one that remains with the current carrying conductors for it's entire
length.
--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
for general use." Thomas Alva Edison

wrote:
OK, let me restate, cause I think I am finally getting it.

for my light fixture in the garage, the neutral (white wire) stays in
the garage. It is the Hot/Switched Hot/Runner (3 wires) that goes to
the House 3way and then to the garage 3way. I got that.

Assuming lites are on the same circuit you can run a common hot plus 2
switch legs per switch.

If I run a #14green wire from the garage to the house as an EGC ground
(just for the switch which is in non-metalic switchbox)...I have
violated code?

With your configuration - feeder with no house-ground wire - a #14
house-garage ground wire is a prohibited separate metalic path.

If I run the green ground wire from the house side switch to the house
EGC, and keep the garage side switch grounded to the garage, would this
allow me to keep the grounds separate and not violate code/be unsafe?

Sounds good to me.

I'm trying to figure out my options short of running another #4AL
feeder cable for the ground. I can pull more #14 wires, but just need
to know how I can make this code compliant and safe.

Thanks!

I don't think you can. You have two mutually exclusive choices:

1: Supply power to the garage with two hot wires, and a combined
ground/nuetral connected to earth in the garage.

This is a feeder, you cannot go to earth ground on the load side of a
service (NEVER).
By code, he must run a 4-wire feeder to the remote panel.

Dennis wrote:


This is a feeder, you cannot go to earth ground on the load side of a
service (NEVER).
By code, he must run a 4-wire feeder to the remote panel.


Read 2005NEC 250.32 (B) (2)

bud--

By code, he must run a 4-wire feeder to the remote panel.
Read 2005NEC 250.32 (B) (2)

Well I be damned. They changed it to allow feeders. I was wrong, and not
more than a little surprised. Haven't had many states reference 2005 yet,
most are still on the 99 where it was referencing services. (After all
these years of it being a no, no...... grin.)

Thanks for the reference Bud.

Dennis