Fire Wire Solid vs. Stranded

[ABLE1]

Hey all,

I just found out that apparently Stranded wire FPLR etc. is available
and is acceptable in wiring of fire alarm systems.

Well that just makes my brain hurt.

It may have been OK per code for sometime or forever but I just became
aware.
I always use solid and I think even after this new info will continue so
it should not make a difference. I just did not think it was allowed as
per code.

Anyone else have input on this??

Educated me!!!

Thanks,

Les

[Jim]

I never heard about stranded FPLR wire. But you're feeling the same way I felt the first time I saw the "new" smoke detectors that allow two wires under the same screw terminal.

Do you know that there is 22 gage FPLR wire? And do you know where it can be used? ...... on a fire loop or on a keypad run or where it is and is not allowed? Also, is it specified anywhere exactly what kind of wire nuts or connectors are allowed to be used in a fire system. I haven't done commercial fire in years and years but back then the answers to the above questions were not apparent.

[ABLE1]

Gee Whiz Jim,
I just learned one new thing and now you want to force me into cramming
more into a already full box. Are you nuts!!! :-)

I don't know the specific answers to your question. Please elaborate
with answers. While doing so, answer the following.

What type of wire ties are to be used in the installation of fire wire in
a plenum area?? Just found out that one during my investigation on the
stranded wire thing.

Smallest gauge wire here is 18awg, no 22awg listed, but there is
stranded stuff.
http://www.westpenn-wpw.com/pdfs/fire-alarm-cables.pdf

Have a good weekend.

Les






>

[Jim]

Well, I got out of commercial fire before I found out the answer to my questions. I used the 22gage wire for keypad/remote indicator panels and AHJ either never noticed or let it pass. I don't know if they even make it anymore.

I always used plain ol wire nuts and never had an inspection problem but I don't know what the "official" answer is.

And, I'm pretty sure I still have a bundle of "plenum" tie-wraps in the back of a drawer somewhere in the van. If I remember right they were purple in color but I don't know if that was just for identification purpose or because of what they were made of.

[Bob La Londe]

I imagine it depends on the application. I've seen approved commercial
systems in schools all wired with THHN stranded in conduit. I don't see any
issue with stranded, and I seem to recall some older style pull stations
that came with stranded pigtails on the actual switch.



"ABLE1" <som...@nowhere.net> wrote in message
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[ABLE1]

Yes, wire ties need to be plenum rated. I would guess if you were above
the
ceiling pulling wire and cut a Phart it would have to be purple or at least
plenum rated, right?? LOL

I have seen 22awg solid "red" assuming FPLR on so takeover jobs. You
are right
may not be available any more.

[ABLE1]

Bob,

I can see that THHN would be acceptable in conduit. Back in the day
most older
schools had 120vac bells. I pulled one a couple of years ago that
was that way. There were just pull stations and they were a hot loop on
120vac.
It was so old it had whiskers and a cane.

It has always been my belief that you had to use solid since if using
stranded
you would have perfect supervision on just one strand if others were broken.
But, then when it went into alarm that one strand could not handle the load
and the system would fail. With solid that would not happen.

Les

[doug]

"ABLE1" <som...@nowhere.net> wrote in message

news:NyPYx.23345$bG2....@fx26.iad...

> Bob,
>
> I can see that THHN would be acceptable in conduit. Back in the day most
> older
> schools had 120vac bells. I pulled one a couple of years ago that
> was that way. There were just pull stations and they were a hot loop on
> 120vac.
> It was so old it had whiskers and a cane.
>
> It has always been my belief that you had to use solid since if using
> stranded
> you would have perfect supervision on just one strand if others were
> broken.
> But, then when it went into alarm that one strand could not handle the
> load
> and the system would fail. With solid that would not happen.
>
> Les
>

This link explains when and why it was changed to allow stranded scroll down
to Sec.760-71(a)

http://ecmweb.com/content/illustrated-changes-1996-necode-part-4


Doug

.

[ABLE1]

Thanks Doug,

Changed in 1996!! Wow, that is very interesting.
Not that I will change my practice of installing solid, but I will now
not question anyone that does. Well maybe I will a little bit.

Again thanks for filling in the blanks.

Give yourself a pay increase for excellent research abilities.

Les

[doug]

"ABLE1" <som...@nowhere.net> wrote in message

news:JuSYx.2077$PV4...@fx16.iad...

Another common assumption seems to be that 3/4" is the minimum size for
conduit runs for fire alarm systems, consequently you see many installations
that have 3/4" conduit to device with only a 18/2 cable inside. A lot of
electricians will swear blind that it is a national code requirement.

Doug

[ABLE1]

There is an old school that I do a lot of work for including the Master
Clock system.
When the school was built in the early '80's or so, there is a single
3/4" conduit
that goes from the Master Clock in the office through out the building
(2 floors)
to every room or space that has a clock and it carries just one(1) #12
solid wire.
It is a hot for the clock correction at 120vac. Every hour it is
energized for
6 seconds "@ 58 minutes" for 1 hour correction and at 6am and 6pm it is
energized
for 12 seconds for 12 hour correction.

Have heard that some teachers have complained that the 6 second buzz
from the clock
on the hour is a distraction to their students. Really???

Les