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Topic: | Is it legal to run Zip Cord In wall ? This thread has 93 replies. Displaying posts 31 through 45. |
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Post 31 made on Tuesday September 15, 2009 at 21:55 |
edizzle Loyal Member |
Joined: Posts: | March 2005 5,916 |
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help set us straight CCD
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I love supporting product that supports me! |
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Post 32 made on Tuesday September 15, 2009 at 22:04 |
Avparts.com Long Time Member |
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On September 15, 2009 at 12:33, Eastside A/V said...
To my knowledge, the issue is it is not coated in a fire retardent (CL2/CL3 rated) material, and as such if there were a fire, it would heat up almost instantly, and become essentially a fuse with a high heat melting plastic sheath...accellerating the progress of a fire to other parts of a house.
This is the same reason extension cables, and power cables being put in wall are not to code. That is correct
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Wil Vitela, owner Why can't more manufacturers listen to custom installers? |
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Post 33 made on Tuesday September 15, 2009 at 23:21 |
Neurorad Super Member |
Joined: Posts: | September 2007 3,011 |
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I think a lot of residential work is not done 'to code', knowingly as well as unintentionally. Most pros know that garage in-walls and IC speakers need to be fire-rated, but how often is that done? I bet most commonly only after an inspector notices it. (Alternative is a drywall back-box/enclosure, FWIW) Do you use fire-rated wire for keypads and speakers, if any alarm notification is via distributed audio? If cables are run by homeowner, then the alarm install is (usually) exempt from firewire. Are all conduit and cable penetrations caulked with fire-rated caulk? Of course the AHJ always has the final say. I try to perform everything 'to code'. Often a pain in the ass. I currently have 2 drywall penetrations in my own garage that are not fire-rated (access panel and blank single-gang wallplate over a hole), but I plan on fixing them.
Last edited by Neurorad on September 15, 2009 23:34.
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TB A+ Partner Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense. -Buddha |
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Post 34 made on Tuesday September 15, 2009 at 23:26 |
CCD Super Member |
Joined: Posts: | August 2005 2,731 |
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On September 15, 2009 at 21:55, edizzle said...
help set us straight CCD I wish I could but I will have to leave that to your AHJ and the NFPA 70. I can tell you that residential installs rarely require plenum as someone posted. We run a ton in commercial and MDUs but almost never in a single family home.
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OP | Post 35 made on Tuesday September 15, 2009 at 23:35 |
39 Cent Stamp Elite Member |
Joined: Posts: | May 2007 17,518 |
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Do you use fire-rated wire for keypads and speakers, if any alarm notification is via distributed audio? If cables are run by homeowner, then the install is exempt from firewire. How many people (show of hands) are routing alarm notifications over the DA system? In a million years i would never suggest or agree to it.
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Avid Stamp Collector - I really love 39 Cent Stamps |
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Post 36 made on Tuesday September 15, 2009 at 23:53 |
edizzle Loyal Member |
Joined: Posts: | March 2005 5,916 |
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On September 15, 2009 at 21:44, CCD said...
Geez...there is so much misinformation posted in this thread that I feel like I am reading at AVS. Read NFPA 70 and take it to heart or be prepared to lose it all one day. Your insurance does not mean anything if you screw up. This is exactly why all states need to require low voltage licenses. You guys throw around terms like plenum CL2 CL3 riser like you actually know what it means. Almost every use that was stated in this thread was incomplete or incorrect.
To answer your question...NO it is not legal in 99% of the US to run lamp cord in walls. The places where it is legal do not have building codes or at least have not adopted NPFA 70. what you are saying no one on here knows, has nothing to do with AHJ or NFPA. you state we are throwing around the terms of cable construction and ratings like we actually know what they mean. you also say no one has gotten a proper use right. if there are definitions for these items, you imply that you know them and we dont. so fill us in. purposely, i have held off of giving direct info other than i do know if it is in in wall it has to be cl rated. i also made a point to the fact that i think some people are getting cl2/3 and plenum rated mixed up. a couple of things i have seen posted here that i believe to be correct are: plenum is to be used in plenum rated air handling space riser is to be used typically commercially when a wire will travel vertically between floors cl2/3 rated wire is required because of a flame retardant in the jacket that is not included in non CL2/3 rated wires like lamp cord, power cords, etc. that is about all i am comfortable saying without doing more research. i am careful handing out advice to the public on subjects this critical.
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I love supporting product that supports me! |
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Post 37 made on Tuesday September 15, 2009 at 23:59 |
Gizmologist09 Advanced Member |
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The other interesting thing is that the plenum rating does not have anything to do with flame spread. It is only concern with toxic fume propagation which is also ironic as most commercial buildings equipped with air handlers have automatic damper and or shut down controls tied to the fire alarm system.
In case of alarm, the air handlers shut down automatically and cannot be restarted with resetting the fire alarm.control system.
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Post 38 made on Wednesday September 16, 2009 at 00:49 |
CCD Super Member |
Joined: Posts: | August 2005 2,731 |
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On September 15, 2009 at 23:53, edizzle said...
what you are saying no one on here knows, has nothing to do with AHJ or NFPA. you state we are throwing around the terms of cable construction and ratings like we actually know what they mean. you also say no one has gotten a proper use right. if there are definitions for these items, you imply that you know them and we dont. so fill us in. purposely, i have held off of giving direct info other than i do know if it is in in wall it has to be cl rated. i also made a point to the fact that i think some people are getting cl2/3 and plenum rated mixed up.
a couple of things i have seen posted here that i believe to be correct are:
plenum is to be used in plenum rated air handling space
riser is to be used typically commercially when a wire will travel vertically between floors
cl2/3 rated wire is required because of a flame retardant in the jacket that is not included in non CL2/3 rated wires like lamp cord, power cords, etc.
that is about all i am comfortable saying without doing more research. i am careful handing out advice to the public on subjects this critical. YES! That is exactly what I meant. My post was not referring to you. I was referring to what someone else posted that said you need plenum rated cable. You are right that people are just throwing terms about pretending to know what they mean. I am just too tired to call the out one by one. Who do you think I am Alan? :-)
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Post 39 made on Wednesday September 16, 2009 at 02:12 |
theKevin Senior Member |
Joined: Posts: | April 2008 1,475 |
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On September 15, 2009 at 18:52, Ernie Bornn-Gilman said...
I drill half inch holes for four-conductor speaker wire. If the wire were burning, there'd be too little air flow throught that 1/2" hole for the burning to go to the next stud bay. The small diameter hole would actually prevent the wire from burning. My guess is that it might go through a one inch hole with one wire in it, and I don't have the time to drill 1" holes when I'm running one wire. a 16/4 cable is about 1/4" in diameter. if it passes through a 1/2" hole, is there not plenty of space for air? if i drill a 1" hole and fill it up with cable, will that pass inspection? i've read that when drilling through a fire break, a contractor needs to fill in the hole with fire rated caulk. i've looked at plenty of prewires, some during construction, and many during retrofit, and i've never seen a cable hole in a firebreak filled in with caulk. seems to me, any airspace at all would allow cable insulation to burn through to the next stud space.
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Artificial intelligence is no match for natural stupidity. |
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Post 40 made on Wednesday September 16, 2009 at 02:18 |
theKevin Senior Member |
Joined: Posts: | April 2008 1,475 |
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On September 15, 2009 at 23:26, CCD said...
I wish I could but I will have to leave that to your AHJ and the NFPA 70. I can tell you that residential installs rarely require plenum as someone posted. We run a ton in commercial and MDUs but almost never in a single family home. i never use plenum rated cable in single family residential installs, afaik it's not required unless run in an air handling space, and that only happens in commercial installations, to my knowledge. i was instructed by a builder superintendant to use plenum rated cable in a commercial installation once, even though the space inside the drop ceiling was not a plenum. he specifically told me that the drop ceiling was not even necessary for the HVAC, but he wanted plenum rated cable installed anyway. i followed his instructions, only to see CAT5 CL2 run all through the same drop ceiling.
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Artificial intelligence is no match for natural stupidity. |
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Post 41 made on Wednesday September 16, 2009 at 02:58 |
2nd rick Super Member |
Joined: Posts: | August 2002 4,521 |
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Another factor required for in-wall rated wire is the over jacket.
Lamp cord does not have this, and is simply the insulated conductors siamesed together.
Any nick or abrasion occurring in the installation of the cable or the remaining construction process is less likely to cause a short circuit if there is an over jacket in addition to the insulation on the individual conductors.
==============
Also the terms "CL-2" and "CL-3" are short for Class 2 and Class 3, which are NEC definitions for low voltage circuits.
If memory is correct <50V is class 2, and 51V-100V is class 3. Those ranges may be off (I don't have the reference materials in hand as I write this), but basically they define two ranges which are less than electrical line voltage (120V).
39, I am more than a little shocked that this was lost on you.... This is CI level 101 stuff.
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Rick Murphy Troy, MI |
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Post 42 made on Wednesday September 16, 2009 at 08:54 |
John Pechulis Loyal Member |
Joined: Posts: | July 2001 7,127 |
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On September 16, 2009 at 02:12, theKevin said...
i've read that when drilling through a fire break, a contractor needs to fill in the hole with fire rated caulk. i've looked at plenty of prewires, some during construction, and many during retrofit, and i've never seen a cable hole in a firebreak filled in with caulk. seems to me, any airspace at all would allow cable insulation to burn through to the next stud space. When I worked in the insulation biz, we were responsible for all the firecaulking. We would go in and firecaulk all contractor's holes and penetrations a few days before insulating the building, after all contractors did their rough-ins. This might be why you don't see it because the insulation generally hides all the wiring. JP
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Post 43 made on Wednesday September 16, 2009 at 10:13 |
cjoneill Select Member |
Joined: Posts: | December 2002 2,174 |
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On September 15, 2009 at 23:26, CCD said...
I wish I could but I will have to leave that to your AHJ and the NFPA 70. I can tell you that residential installs rarely require plenum as someone posted. We run a ton in commercial and MDUs but almost never in a single family home. How many residential houses use plenums? On September 16, 2009 at 02:12, theKevin said...
a 16/4 cable is about 1/4" in diameter. if it passes through a 1/2" hole, is there not plenty of space for air? if i drill a 1" hole and fill it up with cable, will that pass inspection? i've read that when drilling through a fire break, a contractor needs to fill in the hole with fire rated caulk. i've looked at plenty of prewires, some during construction, and many during retrofit, and i've never seen a cable hole in a firebreak filled in with caulk. seems to me, any airspace at all would allow cable insulation to burn through to the next stud space.
Just a small data point, but my house did. On September 15, 2009 at 21:22, Gizmologist09 said...
BTW at AVS, zip cord for anthtnig but tying up tomato plants is a nono.
But there are those of us who actually do understand the "copper is copper" concept as long as the gauge is sufficient I really think that depends on which area of AVS you are in. Chu Gai has been fighting that myth for years. Here's a great quote that I found someplace regarding speaker cable: Recently a poster inaccurately quoted what I have said regarding extensive and carefully-controlled "blind and double-blind" listening tests that we at DAL have conducted over many years to determine if any "truly audible" differences exist between loudspeaker cables representing a wide range of pricing, size and design approaches.
From these comparisons, which encompassed a significant number of competent listeners and a wide range of audiophile amps and loudspeakers, the results we obtained led us to confidently conclude the following:
1) No audible differences existed between any of the cables assessed for lengths under 25 feet - if "stable" power amps and well-designed loudspeakers with reasonable input impedances were used.
2) When audible differences were substantiated they could be traced to:
a) "high-performance" power amps with excessive inverse-feedback and inherent stability problems that caused them to became unstable and oscillate at supersonic frequencies (creating audible distortion) when used with some low loss, high capacitance, low-impedance cables, and/or b) a loudspeaker cable with a high series inductance and or a high series resistance, which sometimes caused an audible roll-off of high frequencies and/or a "dulling" of transient detail when used with a loudspeaker whose input impedance dropped below about 2 ohms over a reasonable range of frequencies, especially above about 10 kHz.
Beyond these special cases, no audible differences were ever substantiated between the most expensive, exotic-looking, widely-advertised loudspeaker cables and quality #12 AWG ZIP Cord having the same length.
The many listening comparisons we have made over the past 20-odd years between audiophile loudspeaker cables were carefully controlled according to proper scientific method and good engineering practices. Every reasonable effort was made to ensure that listening comparisons did not encompass spurious factors that might bias or skew results. A wide variety of music and test tones (impulses, tone-bursts, etc.) were used, along with a variety of audiophile loudspeakers and power amps. The amplifiers used varied in price from about $200 to over $10,000. The rooms used for critical listening comparisons were always acoustically well-damped, typically about 25 feet wide by 15 feet deep, with the loudspeakers placed along the long wall, about 10 feet from the listener and separated by an included angle of about 90 degrees. Listeners included DAL employees, salespersons of local audio stores, and numerous visiting audiophiles.
Among the approaches used in evaluating whether verifiable audible differences existed between different loudspeaker cables were:
1) pretending to switch cables but not doing so, 2) switching between cables but not letting the listener know which was being heard (blind and double-blind regimens), 3) switching between cables while keeping the listener informed as to which cable was being used.
The results we have obtained consistently correlate very well with those published within professional and trade journals by competent engineers who have performed similar tests and comparisons between cables. And, they have always correlated with those expected from the teachings of well-known transmission-line theory, network theory, etc. and predictions based upon the proper interpretation of a full set of lab-quality measurements.
There really are no relevant unknowns with respect to transmission-line theory and the measurement of meaningful cable performance parameters. The goofy beliefs and theories that need to be questioned are those often loudly annunciated by persons who pretend they possess competent knowledge and understanding of cable theory and measurement but lack the professional-level credentials and underpinnings to do so. The bottom line is very simple: if it can be heard, it can be identified, measured and quantified by well-known means within a well-equipped laboratory manned by personnel possessing appropriate professional credentials. (Those who believe otherwise are doomed to be victims of those who pursue the design and sale of products based upon pseudo science and nonsensical advertising claims.)
Sadly, the allure of expensive, "high-tech appearing" loudspeaker cables can be traced to an industry typically missing qualified electrical engineering personnel but brimming with personnel who excel at composing "great-sounding advertising prose" containing claims for technology and performance that are virtually baseless. (A sad commentary regarding a very large and profitable industry!)
But, the advertisements of some cable manufacturers do contain what are purported to be measured comparisons between different cables, including ZIP Cord, which is portrayed to exhibit only about 3% efficiency at 60 Hz. However, common sense reveals that such a low efficiency would cause a typical "AC extension cord" to turn "white hot" if connected to an ordinary toaster. Hmmm!
Another advertisement compares loudspeaker cables according to their Joule rating - but a Joule is merely a watt-second, used as a unit of energy-storage when comparing batteries or some capacitors. Hmmm! Thus, such graphs portray totally meaningless information that is not only false but also misleading and downright silly from an engineering point-of-view. When asked why they do not publish meaningful measured performance specifications for their cables, such as loss Vs frequency into typical loudspeaker load impedances, series resistance, parallel capacitance, series inductance, frequency dispersiveness, etc., representatives of most large cable companies usually reply that such performance attributes are meaningless. Hmmm!
I have recently asked five very competent Professors of Electrical Engineering at prominent universities their opinion of audiophile loudspeaker cable design and advertising. The language of their replies would probably not be permitted even here on the INTERNET. Needless to say, they share the feelings of all competent and informed electrical engineers that the advertising claims and specifications for audiophile loudspeaker cables are without substance and cannot be verified by theory, measurements nor proven by competent blind listening comparisons. The same conclusions have been stated in a few magazine articles and peer-reviewed audio journal papers by authors possessing credible academic and technical backgrounds.
Thus, the question arises as to why any competent manufacturer would not at least attempt to design loudspeaker cables with measurable electrical properties that represent the teachings of network/transmission-line theory and the fruits of good engineering practice? For example, at very high audio and low radio frequencies, cables with a relatively long length can best be characterized by applying "transmission-line theory", while at lower frequencies it is easier (and probably more accurate) to design and analyze cables by using "network theory".
For example, using the teachings of transmission-line, the "optimum cable" would be one whose "characteristic impedance" was equal to the average impedance of the load. However, while this solution somewhat applies to loudspeaker cables, it results in a cable whose relatively large capacitance and low inductance might cause some "high-performance" (but frequently unstable) power-amps to oscillate - usually at super-sonic frequencies, detectable as audible distortion on transients, etc. (This is the reason that some expensive audiophile loudspeaker cables incorporate an expensive, hi-tech looking box at the loudspeaker end of the cable which houses a simple inexpensive resistor and capacitor, often called a "Zobel Network". Hmmm!
Recognizing what frequently are shortcomings of the "ideal cable" designed according to transmission-line theory, competent engineers apply the teachings of "network theory" to design loudspeaker cables with lengths less than about 25 feet. In this case, an ideal loudspeaker cable becomes one whose series resistance, series inductance and parallel capacitance are all minimal. The combination of these properties insures the lowest loss across the audio spectrum while minimizing the probability of amplifier instability. Such a cable might be one with very large diameter, low resistance wires, separated by a distance that minimizes capacitance without increasing inductance beyond an amount that would alter high-frequency performance.
Achieving either of these design properties and goals can be accomplished without incurring a high engineering and manufacture costs that might lead to high retail prices - such as those currently being charged for some exotic, hi-tech looking cables with questionable performance properties. So, why not design, manufacture and competitively market loudspeaker cables based upon advertising that articulates their meaningful design parameters and competently measured electrical specifications - rather than the flooby-dust, buzzard-salve and gobbledygook specs presently found in too many cable advertisements? Are most cable manufacturers afraid to advertise meaningful performance parameters, such as the resistance, inductance, resistance, propagation-factor, etc, for their cables. (Can most cable manufacturers even measure them?) Hmmm!
So, the best present advise is very simple: CAVEAT EMPTOR (let the buyer beware)!
Best of listening,
John Dunlavy To bring this back on topic, here's an NEC substitution chart for cable types: [Link: generalcable.com]Here's a pretty good summary of cable types along with an abreviated substitution chart: [Link: generalcable.com]CJ
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I'm not a pro |
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Post 44 made on Wednesday September 16, 2009 at 10:24 |
Jeff Wagner Founding Member |
Joined: Posts: | January 2002 368 |
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Wow,
I'm amazed and/or amused by some of the comments. Kofi nailed it - in all the places I've installed around the country the "Marked and Listed" was the most important issue for inspectors. Marked means that it has to have a rating listed on the outside jacket. Listed means that it must be tested by a recognized agency (often UL here in the states, but there are others). Until you are pulling wire in an MDU you will rarely ever need plenum wire.
Jeff
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Post 45 made on Wednesday September 16, 2009 at 11:02 |
Kofi Long Time Member |
Joined: Posts: | October 2005 352 |
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On September 16, 2009 at 10:24, Jeff Wagner said...
Until you are pulling wire in an MDU you will rarely ever need plenum wire. Just make sure the space over a drop ceiling that you are pulling cable through is not used as an HVAC plenum. May be rare, but possible in resdiential construction. Definately more common in MDU and commercial. And while you are up there, make sure all your fancy plenum and in ceiling speakers are properly secured by cable trays or other 'code compliant' support systems.
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