Wire motions with cat5e?

[AceCannon]

I've been advised that it may not be smart.

I was hoping to wire them with cat5e, use 4 conductors for the motion, then use the extras for the small Elk 32ohm speakers.

 

[wuench]

I've been advised that it may not be smart.

I was hoping to wire them with cat5e, use 4 conductors for the motion, then use the extras for the small Elk 32ohm speakers.

Recommended wiring for motions is 22/4. Cat5 is 24 guage, so if you doubled up pairs you'd be ok. But I really doubt you want 24 guage for speakers either. Not sure what is recommended there but I ran 18 guage for my speakers.

 

[AceCannon]

Recommended wiring for motions is 22/4. Cat5 is 24 guage, so if you doubled up pairs you'd be ok. But I really doubt you want 24 guage for speakers either. Not sure what is recommended there but I ran 18 guage for my speakers.

Yes, I figure the signal pair for the motions should be fine with cat5e's 24ga. I guess I was hoping someone would chime in and say 24ga is fine for power to the motions, as well.

As for the speakers, I thought maybe the remaining 4 conductors could be doubled-up - two each for + and -.

 

[upstatemike]

Recommended wiring for motions is 22/4. Cat5 is 24 guage, so if you doubled up pairs you'd be ok. But I really doubt you want 24 guage for speakers either. Not sure what is recommended there but I ran 18 guage for my speakers.

Yes, I figure the signal pair for the motions should be fine with cat5e's 24ga. I guess I was hoping someone would chime in and say 24ga is fine for power to the motions, as well.

As for the speakers, I thought maybe the remaining 4 conductors could be doubled-up - two each for + and -.

I use cat-5 for motions and have no problems. The current draw on a motion sensor is low and unless your run is very long the voltage drop on the power leads will not be enough to cause a problem. The speakers should also not be an issue unless the wire resistance is high enough to drop the volume too much. Probably less of an issue with 32 ohm speakers than it would be for 8 ohm speakers. (Adding 2 or 3 ohms to a 32 ohm load is less of a change than adding 2 or 3 to an 8 ohm load would be.)

 

[tmbrown97]

I second upstatemike in that it should be fine for those reasons... I wouldn't do it out of preference for working with the 22/2 for the speakers separate than the solid-core of Cat5, but that's my own opinion. I did use Cat5 for my motions and just because the wires were there, I doubled them up - but not out of any perceived need (backup in case any of the fragile wires broke).

 

[AceCannon]

Perhaps I should have purchased a roll of cat6 for these reasons.

Although Wikipedia points out that the specs for cat6 do not require 22awg wire:

Although Cat-6 is sometimes made with 23 gauge wire, this is not a requirement; the ANSI/TIA-568-B.2-1 specification states the cable may be made with 22 to 24 AWG gauge wire, so long as the cable meets the specified testing standards.

And those testing standards have to do with "crosstalk" and system noise, not voltage drop.

 

[tmbrown97]

Exactly. Cat5/6 are designed for carrying signal, not voltage. It's precisely designed to optimize noise and crosstalk reduction and reduce interference... It's just convenient that it can handle low voltages as well.

Personally, I'd much rather run my voltage over stranded wires - they're less fragile and easier to work with. Someone did an explanation recently too of how it can carry current more efficiently because the current only passes on the outside of the wire, therefore providing more surface area allows current to pass more efficiently. I don't know this for sure, but it sounded good.

Cat6 may get you a larger gauge (in most cases), but more headaches with it. You certainly won't need it for anything a security system will be doing in the next 15 years. About the only benefit for what you're doing is that it's one less run - but personally, I'd just do the separate runs - and I'd probably use 22/4 for my motions.

 

[upstatemike]

Stranded wire is more rugged and does carry more current for a particular gauge but it is a pain to terminate in any sort of high density way. I use 66 blocks to terminate all of my field wiring except hi-fi audio, RF Coax, and fire alarm. Stranded wire will loosen over time if punched onto these blocks so I stick to solid wire as much as possible. Cat-5e is the swiss army knife of wire and can be adapted to work for most automation and communications applications.

 

[tmbrown97]

True - definitely a preference issue. Plus, you spoiled people have basements and room to work :angry: - all my stuff is best terminated end-to-end because it's in my master closet.