Mixing high & low voltage wires in electrical conduit?
 

Is it allowed to run both 110v wire (either THHN or Romex) and low
voltage alarm wire (e.g., 4 conductor 22 gauge) in the same 1/2" rigid
metal conduit?

I probably will have one 2-conductor #14 Romex wire for overhead
garage light plus a couple of alarm cables for the window, door, and
heat sensors.

Thanks

No. I think the code is you must run the same guage wire for the
highest voltage running through the conduit. So if your running 14
guage Romex for your HV, you must also run at least 14 guage for the
LV. Thats what I did for my garage. I ran 14 guage for the electrical,
then I ran 2-14 guage for my alarm circuits.

blueman wrote:
Is it allowed to run both 110v wire (either THHN or Romex) and low
voltage alarm wire (e.g., 4 conductor 22 gauge) in the same 1/2" rigid
metal conduit?

I probably will have one 2-conductor #14 Romex wire for overhead
garage light plus a couple of alarm cables for the window, door, and
heat sensors.

Thanks
I think the insulation on the low voltage has to be rated to insulate
the highest voltage in order to do what you want to do.

I'm not an electrician but some thoughts... unless there is a risk of
the conductors becoming overheated for some reason I don't see why not.
I think when you have two or runs of NM in any kind of conduit what
you want to avoid is the cables pulling the same voltage, or you might
have inductive heating problems? I think the NEC goes into detail
about not pulling two cables through conduit that will be on the same
circuit??? If I am correct I think you would be OK with what you
described.

On 6-Jul-2005, wrote:

I'm not an electrician but some thoughts... unless there is a risk of
the conductors becoming overheated for some reason I don't see why not.

I'm not trying to be a usenet cop or anything but speculating about
electrical issues does no one any good.
If you know the answer, great, post away. If you don't know the answer,
then just let someone who does post it.

ml

wrote in message
...
I'm not trying to be a usenet cop or anything but speculating about
electrical issues does no one any good.
If you know the answer, great, post away. If you don't know the answer,
then just let someone who does post it.

Agreed. The NEC dictates a lot of things that wouldn't be obvious to the
average person via speculation.

And this goes to pretty much everyone in the thread, not just this reply.
If you can't cite the proper code, you probably shouldn't respond.

-Tim

"blueman" wrote in message
...
Is it allowed to run both 110v wire (either THHN or Romex) and low
voltage alarm wire (e.g., 4 conductor 22 gauge) in the same 1/2" rigid
metal conduit?

I probably will have one 2-conductor #14 Romex wire for overhead
garage light plus a couple of alarm cables for the window, door, and
heat sensors.

In my city you can't, and Brinks (who's brand alarm I have) wouldn't install
in the same conduit as line voltage.

There's probably very good reasons for this, the main ones I'm thinking of
is interference with the low voltage devices, and inexperienced
do-it-yourselfers getting zapped by the line voltage wires by mistaking them
for the LV wires.

There are at least three things I can think of to do what you want.

You can use wireless alarm sensors. Not my favorite idea, but many folks
like them.

You can run another conduit specifically for low voltage devices. That's
what I did when I renovated my patio, using 1" conduit. I can run CAT 5,
coax, alarm, LV, and anything else I want except line voltage, which has
it's own conduit.

You can run the low voltage wires underground without conduit. You can use
either low voltage or line voltage wire that's rated for underground burial,
and use metal conduit from underground to inside your house and garage,
which should make any code inspector happy.

The last two depends on the construction around your garage, of course. If
you can do both, I suggest the separate conduit, where in the future you can
run additional wiring with ease, and they'll be protected from moisture and
such.

Pagan

Because there is always one answer to every question.

Pagan wrote:
"blueman" wrote in message
...

Is it allowed to run both 110v wire (either THHN or Romex) and low
voltage alarm wire (e.g., 4 conductor 22 gauge) in the same 1/2" rigid
metal conduit?

I probably will have one 2-conductor #14 Romex wire for overhead
garage light plus a couple of alarm cables for the window, door, and
heat sensors.


In my city you can't, and Brinks (who's brand alarm I have) wouldn't install
in the same conduit as line voltage.

There's probably very good reasons for this, the main ones I'm thinking of
is interference with the low voltage devices, and inexperienced
do-it-yourselfers getting zapped by the line voltage wires by mistaking them
for the LV wires.

There are at least three things I can think of to do what you want.

You can use wireless alarm sensors. Not my favorite idea, but many folks
like them.

You can run another conduit specifically for low voltage devices. That's
what I did when I renovated my patio, using 1" conduit. I can run CAT 5,
coax, alarm, LV, and anything else I want except line voltage, which has
it's own conduit.

You can run the low voltage wires underground without conduit. You can use
either low voltage or line voltage wire that's rated for underground burial,
and use metal conduit from underground to inside your house and garage,
which should make any code inspector happy.

The last two depends on the construction around your garage, of course. If
you can do both, I suggest the separate conduit, where in the future you can
run additional wiring with ease, and they'll be protected from moisture and
such.

Pagan


Sounds like good advice. Asuming the National Electrical Code applies,
this is not permitted with separate wires. With cables it is up to the
Authority Having Jurisdiction (ispspector) who, I think, would not be
happy.

As noted the line voltage circuit could produce noise in the LV cable
through capacitive and inductive coupling.

Bud--

You can also read all the messages in this short thread

You can be ignored too, zipperhead.

Apparently not in your case.

Whoa there... let me get this straight...

And this goes to pretty much everyone in the thread, not just this reply.
If you can't cite the proper code, you probably shouldn't respond.

So you're saying that it's not OK for me to speculate from the
viewpoint of risk avoidance in inductive heating in electrical circuits
(which I made pretty clear I was doing, because I'm not an
electrician), bit it **IS OK** that he should be doing his own
electrical work when the OP seemingly doesn't know where to find or how
to open an NEC manual or other suitable reference to determine
requirements for running conductors in conduit??? Who gives a rat's
ass about citing the correct code chapter and verse if you don't know
what the hell you are doing to begin with???

I'm going to bake a cake and I don't know how to turn the oven on. The
mixing spoon is too cracked and I'm short three eggs. If the OP
insists on doing the work himself and comes to usenet for help, well...
that's his problem.

For the OP, www.nfpa.org sells residential wiring textbooks and
inspector checklists for the uninitiated for about $60 each. They are
based on the NEC. Easy to follow and read. They expire every three
years. 2005 is a good time to buy since the NEC was recently revised.

I didn't want you to get lost again

Electrical workers in US make decent wages compared to banana pickers in
Guatemala.

An electrical switch needs to be rated for the application.

Electrical workers in US make decent wages compared to banana pickers in
Guatemala.

Then if the OP is a banana picker in Guatemala the US NEC is probably
not enforced in his jurisdiction. He can shove damn well anything
through that conduit and hope for the best.

G Henslee wrote:

wrote:

I didn't want you to get lost again

Who are you talking to this time?

We have to remember that some people have no idea how news browsers
can be set -- that is, so that they do NOT display already read items.
Also, other posts sometimes get between others and make it impossible
to follow a thread without some context!

--
Phil Munro Dept of Electrical & Computer Engin
Youngstown State University
Youngstown, Ohio 44555

"Pagan" writes:
"blueman" wrote in message
...
Is it allowed to run both 110v wire (either THHN or Romex) and low
voltage alarm wire (e.g., 4 conductor 22 gauge) in the same 1/2" rigid
metal conduit?

I probably will have one 2-conductor #14 Romex wire for overhead
garage light plus a couple of alarm cables for the window, door, and
heat sensors.

In my city you can't, and Brinks (who's brand alarm I have) wouldn't install
in the same conduit as line voltage.

There's probably very good reasons for this, the main ones I'm thinking of
is interference with the low voltage devices, and inexperienced
do-it-yourselfers getting zapped by the line voltage wires by mistaking them
for the LV wires.

There are at least three things I can think of to do what you want.

You can use wireless alarm sensors. Not my favorite idea, but many folks
like them.

You can run another conduit specifically for low voltage devices. That's
what I did when I renovated my patio, using 1" conduit. I can run CAT 5,
coax, alarm, LV, and anything else I want except line voltage, which has
it's own conduit.

You can run the low voltage wires underground without conduit. You can use
either low voltage or line voltage wire that's rated for underground burial,
and use metal conduit from underground to inside your house and garage,
which should make any code inspector happy.

The last two depends on the construction around your garage, of course. If
you can do both, I suggest the separate conduit, where in the future you can
run additional wiring with ease, and they'll be protected from moisture and
such.

Pagan

Actually, my situation is the reverse. I already have the low voltage
alarm wires run in rigid metal conduit up the garage wall and across
the ceiling to a centrally located heat sensor. I was hoping that
maybe I could use that same conduit to also run cable for a ceiling
light that I need to relocate. Of course, I could add a parallel run
of conduit, but I was hoping to avoid the racecourse look of multiple
conduit runs snaking across my ceiling (in my mind, one is more than
enough visually :).

writes:
Whoa there... let me get this straight...

And this goes to pretty much everyone in the thread, not just this reply.
If you can't cite the proper code, you probably shouldn't respond.

So you're saying that it's not OK for me to speculate from the
viewpoint of risk avoidance in inductive heating in electrical circuits
(which I made pretty clear I was doing, because I'm not an
electrician), bit it **IS OK** that he should be doing his own
electrical work when the OP seemingly doesn't know where to find or how
to open an NEC manual or other suitable reference to determine
requirements for running conductors in conduit??? Who gives a rat's
ass about citing the correct code chapter and verse if you don't know
what the hell you are doing to begin with???

I'm going to bake a cake and I don't know how to turn the oven on. The
mixing spoon is too cracked and I'm short three eggs. If the OP
insists on doing the work himself and comes to usenet for help, well...
that's his problem.

For the OP, www.nfpa.org sells residential wiring textbooks and
inspector checklists for the uninitiated for about $60 each. They are
based on the NEC. Easy to follow and read. They expire every three
years. 2005 is a good time to buy since the NEC was recently revised.

There is a difference between not knowing basic electrical code and
wiring vs. not knowing a specific and rarely used detail such as in my
question. I asked the question here to expand my knowledge and at
least get some directional pointers to the right answer -- who knows,
maybe my question has a simple and unanimously agreed upon answer or
maybe it doesn't in which case I will need to look elsewhere...

Just as an anecdote, I recently hired licensed master electricians to
rewire major portions of our house and I can assure you that they did
not know details of the code outside of their daily work habits -- I
am also pretty sure that they are not the book types that would be
adept at skimming and interpreting the arcane details of code that
they were not trained in. That does not mean that they are not capable
of doing the wiring if informed of what is allowed.

There is a difference between not knowing basic electrical code and
wiring vs. not knowing a specific and rarely used detail such as in my
question. I asked the question here to expand my knowledge and at
least get some directional pointers to the right answer -- who knows,
maybe my question has a simple and unanimously agreed upon answer or
maybe it doesn't in which case I will need to look elsewhere...

I agree with you blueman, I was actually trying to help with my limited
knowledge of using conduit and what I've read in the NEC about
inductive heating, might be something you can look into and expand your
knowledge of electrical. I hope you didn't mistake me for a real
electrician and inadvertently burn your house down while reading my
original response to your post. ;)

I wasn't seriously suggesting that you couldn't open a book. But I do
think it is rediculous for individuals on usenet to tell others to keep
their thoughts to themselves in a prevelently DIY forum. The free flow
and exchange of ideas must not be impeded.

And I say that because I am now more knowledgeable of cabling
requirements in conduit. I only had a part of the story with voltage
issues and inductive heating. Perhaps you were not aware of inductive
heating issues and therefore a mutual exhange may have occured.

Good luck with your project blueman

"joe" wrote in message
.. .
blueman wrote:
Is it allowed to run both 110v wire (either THHN or Romex) and low
voltage alarm wire (e.g., 4 conductor 22 gauge) in the same 1/2" rigid
metal conduit?

I probably will have one 2-conductor #14 Romex wire for overhead
garage light plus a couple of alarm cables for the window, door, and
heat sensors.

Thanks
I think the insulation on the low voltage has to be rated to insulate
the highest voltage in order to do what you want to do.

Right on.

You will pay dearly for that stuff rated at 300 volts. Available, even at
600 volt insulation

By the way romex typically is not rated to be in conduit.

On Wed, 06 Jul 2005 13:31:10 GMT, blueman wrote:

Is it allowed to run both 110v wire (either THHN or Romex) and low
voltage alarm wire (e.g., 4 conductor 22 gauge) in the same 1/2" rigid
metal conduit?

I probably will have one 2-conductor #14 Romex wire for overhead
garage light plus a couple of alarm cables for the window, door, and
heat sensors.

Thanks

According to the NEC, you can only have signalling voltage and line
voltage in the same enclosure if it's a listed assembly. (Furnace,
air conditioner, etc.) Short answer, no!

Dan

So if I am reading the code English properly, what I am asking is not
allowed even if the 110v (Class 1) wires are enclosed in Romex cabling
unless there is some additional "barrier" between the power and alarm
wires.
Right?

This is not allowed. SQLit had the answer some time back... Romex does
not belong in ANY conduit to begin with...

It is not required to be in conduit unless protecting it from physical
damage, I would 'suppose' it would exceed the fill requirements of the
conduit you are proposing to use, and it should not be mixed with low
voltage or alarm signaling wiring because of the insulation rating
differences.

Many alarm panels use semiconductor inputs, which sense either a opening
or closing of a circuit. Placing the wiring within close proximity to
other wiring can cause interference, and the alarm may either trip for
no reason or fail to trip when it's needed.

There is no need to place your romex in conduit. If you must use
conduit, use a separate one and THHN wire. You can also use flexible BX
cable with the appropriate fittings.

Jake

SQLit wrote:
"joe" wrote in message
.. .

blueman wrote:

Is it allowed to run both 110v wire (either THHN or Romex) and low
voltage alarm wire (e.g., 4 conductor 22 gauge) in the same 1/2" rigid
metal conduit?

I probably will have one 2-conductor #14 Romex wire for overhead
garage light plus a couple of alarm cables for the window, door, and
heat sensors.

Thanks

I think the insulation on the low voltage has to be rated to insulate
the highest voltage in order to do what you want to do.


Right on.

You will pay dearly for that stuff rated at 300 volts. Available, even at
600 volt insulation

By the way romex typically is not rated to be in conduit.


better off running separate conduit, eh.

"blueman" wrote in message
...
"Pagan" writes:
"blueman" wrote in message
...
Is it allowed to run both 110v wire (either THHN or Romex) and low
voltage alarm wire (e.g., 4 conductor 22 gauge) in the same 1/2" rigid
metal conduit?

I probably will have one 2-conductor #14 Romex wire for overhead
garage light plus a couple of alarm cables for the window, door, and
heat sensors.

In my city you can't, and Brinks (who's brand alarm I have) wouldn't
install
in the same conduit as line voltage.

There's probably very good reasons for this, the main ones I'm thinking
of
is interference with the low voltage devices, and inexperienced
do-it-yourselfers getting zapped by the line voltage wires by mistaking
them
for the LV wires.

There are at least three things I can think of to do what you want.

You can use wireless alarm sensors. Not my favorite idea, but many folks
like them.

You can run another conduit specifically for low voltage devices. That's
what I did when I renovated my patio, using 1" conduit. I can run CAT 5,
coax, alarm, LV, and anything else I want except line voltage, which has
it's own conduit.

You can run the low voltage wires underground without conduit. You can
use
either low voltage or line voltage wire that's rated for underground
burial,
and use metal conduit from underground to inside your house and garage,
which should make any code inspector happy.

The last two depends on the construction around your garage, of course.
If
you can do both, I suggest the separate conduit, where in the future you
can
run additional wiring with ease, and they'll be protected from moisture
and
such.

Pagan

Actually, my situation is the reverse. I already have the low voltage
alarm wires run in rigid metal conduit up the garage wall and across
the ceiling to a centrally located heat sensor. I was hoping that
maybe I could use that same conduit to also run cable for a ceiling
light that I need to relocate. Of course, I could add a parallel run
of conduit, but I was hoping to avoid the racecourse look of multiple
conduit runs snaking across my ceiling (in my mind, one is more than
enough visually :).

Pull the alarm wires out of the conduit and run them alongside it. Then use
the conduit for the power line.

In article , "SQLit" wrote:

By the way romex typically is not rated to be in conduit.

Wrong.

Not only does the NEC *permit* running romex in conduit, where needed for
protection from physical damage the Code _explicitly_requires_ it.




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

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

In article pdZye.139658$xm3.49327@attbi_s21, Jake wrote:

This is not allowed. SQLit had the answer some time back... Romex does
not belong in ANY conduit to begin with...

False. There is *nothing* in the NEC that prohibits running Romex in conduit.

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

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

wrote in message
ups.com...
So you're saying that it's not OK for me to speculate from the
viewpoint of risk avoidance in inductive heating in electrical circuits
(which I made pretty clear I was doing, because I'm not an
electrician), bit it **IS OK** that he should be doing his own
electrical work when the OP seemingly doesn't know where to find or how
to open an NEC manual or other suitable reference to determine
requirements for running conductors in conduit???

Correct. He has asked for help here in this newsgroup. The fact that he's
asking and not just cramming as many as he can in the conduit shows that he
wants to do it right. Not everyone can/wants to understand the code books.
On the other hand, if you're going to reply to his response, you should know
what you're talking about.

Replies like "this should work" or "I don't think that would be a problem"
are of little help when the code says Yes or No directly.

-Tim