CAT-5 for doorbells ??

[sundowner]

I was walking through the competitions job the other day and saw something a little hoaky!!
They were using left over CAT-5 cable to wire the doorbells. Is this the way you other guys are doing things??? I was under the impression that CAT-5 was "communication Cable" and absolutely not for power,whether it be low voltage or power limited or the man on the moon, to me this a violation. It is also poor workman ship, in my humble opinion only...

Any thoughts guys
steve in WI

 

[tom baker]

Re: CAT-5 for doorbells ??

A door bell circuit is a ARt 725 Class 2 power limited application. Cat 5 cable is not listed for this application. Besides door bell cable is 18 gage, cat 5 is 24, for a long run there would be large voltage drop, unless they parallel up some pairs.

 

[hbiss]

Re: CAT-5 for doorbells ??

I have heard of some guys that will run CAT5 in case at some time the owner may want to install one of the video door systems. I agree with Tom that CAT 5 should not be used for CL2 doorbell circuits. If you want to run it for future use fine- but you need to run CL2 wiring for the doorbell also.

I also feel that this is sloppy or lazy work. CAT5 has become the "universal" cable for anything telecom, computer or LV with a lot of people. You can always tell a job that has been done by a craftsman that knows the trade because he chooses his cables and materials wisely and installs them properly.

-Hal

 

[sundowner]

Re: CAT-5 for doorbells ??

Thanks guys, I thought something was wrong with that picture. I knew this would be the place to find out for sure. There is a lot to be said for neat orderly work, installed correctly the first time...from a fair bid.

Thanks again guys

Steve in WI

 

[midget]

Re: CAT-5 for doorbells ??

Someone once told me that CAT-5 was muli purpose... I was like mmm yeah, and they just make all those other wires for fun?

 

[don_resqcapt19]

Re: CAT-5 for doorbells ??

Table 725.61 permits the use of "CM" cables as a substitute for "CL2" cables. Cat-5 is listed as a "CM" cable. Yes, agree that the conductor size is small, but don't see a code restriction on its use for doorbells.
Don

 

[macmikeman]

Re: CAT-5 for doorbells ??

Thanks Don for clearing this up. Now for my turn, the other day I wired the sensors for a garage door with cat-5 since I forgot to grab a box of alarm wire from the shop. Should I go back and remove it before the drywallers show up or am I ok with this?

 

[al hildenbrand]

Re: CAT-5 for doorbells ??

So, If I parallel the 22 or 24 ga conductors, what are the ampacities possible for combinations of 2, 3 or 4 conductors. . . ?

And can I just twist the wires together at the doorbutton end and land them under the button terminal screws?

 

[hbiss]

Re: CAT-5 for doorbells ??

I forgot to grab a box of alarm wire from the shop...

If you forgot your 10/2 why not just do a couple of runs of 14/2? Heck, why even carry 10/2?

Should I go back and remove it?

I would. It's sloppy work and your name is all over it! If there is one thing I hate it's going to a job and finding some type of UTP run all over for just about anything. Is it telephone? data? doorbell? thermostat? WHAT?

If I parallel the 22 or 24 ga conductors, what are the ampacities possible for combinations of 2, 3 or 4 conductors?

Yeah right, God help the poor guy who has to figure out which conductors you twisted together.

Like I said it's sloppy work.

-Hal

 

[iwire]

Re: CAT-5 for doorbells ??

Originally posted by hbiss:
I forgot to grab a box of alarm wire from the shop...

If you forgot your 10/2 why not just do a couple of runs of 14/2? Heck, why even carry 10/2?

Hal I think you are going a little extreme here.

Bob

 

[hbiss]

Re: CAT-5 for doorbells ??

I can tell you where if you want to go back and replace it.

I'm on my way!

-Hal

 

[don_resqcapt19]

Re: CAT-5 for doorbells ??

And I think that Ex #2 to 310.4 will even let us parallel the wires in the Cat-5 in many cases.
Don

 

[hbiss]

Re: CAT-5 for doorbells ??

But I think #2 (C) would prohibit it in most current carrying applications seeing as these are only #24 ga.

But then chapter 3 doesn't apply to Art 725 applications unless specifically referenced anyway.

-Hal

 

[macmikeman]

Re: CAT-5 for doorbells ??

scuze me Hal, I did not say anything in my post about parrallel connections, just wondered if it is ok to use this cable to wire the garage door photo sensor. I believe the photo sensors are electronic devices which like alarm contacts need less than 1/2 volt and very little current to monitor a set of closed contacts in the remote devices. I see no need to twist any of the pairs together to make the circuit. Having followed this thread carefully I think the cable type is ok after all.

 

[hbiss]

Re: CAT-5 for doorbells ??

Yeah, it'll be fine. Just not what I like to see but that's just me I guess.

-Hal

 

[rattus]

Re: CAT-5 for doorbells ??

In the Army, we used a lot of "Commo Wire" which was no more than a twisted pair telephone cable. But, since we had no HDs over there, we used it for everything. We didn't have duct tape or baling wire either, so commo wire had to do.
!

 

[kiloamp7]

Re: CAT-5 for doorbells ??

rattus - wasn't the offical Army designation WD-1/TT ? Been a long time, hard to remember.

But it had black insulation on each conductor of the pair. Each conductor was made up of (7) strands. (4) of copper & (3) of steel.

Are we talking about the same "commo wire" ?

 

[rattus]

Re: CAT-5 for doorbells ??

Kilo, the main thing I remember about the Army is my serial number and the day I got out! I recall one guy who said all the wanted out of the Army was "OUT" so he could go back to Tennessee and look a mule in the butt again.

Yes, the commo wire was a twisted pair with black plastic insulation. It must have had some steel in it because it was tough. Sometimes it was strung on poles, but often it was just laid on the ground. We had tons of it in our Signal Company, but never knew the official designation for it.

 

[bensonelectric]

Re: CAT-5 for doorbells ??

CAT-5 is used for phone wire, and the bell trigger usually puts out somewhere inbetween 100 and 140 volts (kinda hard to remember) I dont see a doorbell beeing exactly the biggest load, certanly not much more than a phone bell... Correct me if I am wrong on any of this because I am not 100 percent positive.

 

[hurk27]

Re: CAT-5 for doorbells ??

Correct me if I am wrong on any of this because I am not 100 percent positive.

Yep as the ring voltage is around 90 volts but it is the current that is what makes the difference in these two circuits not the voltage. A phones ring current is only 0.4amps verses 1 to 5 amps for a door bell.
Where the voltage comes into play is a common door bell transformer only has between 10 to 16 volts and a voltage drop will be very critical to operation as if you have a 5 volt drop on a 10 volt Edwards system it would be a 50% voltage drop and you would be lucky to get it to ring. Then there's the possibility of the cat5 (24awg) over heating and causing a fire so there are many reasons why we have to run the correct wire for the purpose.

Oh one other thing: Just because the code say's safe from fire hazard for a class 2 source does not mean that it can not cause a fire! as it does cause a fire every day in most furnaces. this statement only means that it is not likely to cause a fire when the whole circuit is properly installed and this includes the type of wire that is used.