atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Security, Alarms and Paging 18/4 speaker wire for Valcom paging

I have a customer with Valcom 24V Paging horns in several bays using NEC Aspire phone system


The cable that has been running this has been there for probably 20 to 30 years (Cat 3 indoor cable) I may have installed it😳

They are having intermittent problems, so I am suggesting running a new cable



They have their own power supplies in each bay

The Cable is outside under an overhang (Loading Dock)

I was just going to run some cat six outside cable

Which I had in my truck until I realize that I only had about 400 feet but I needed about 700/800 feet I didn’t want to create any spices that were unnecessary

And then I was thinking, technically, I only need one pair
For audio. Then I thought about running just regular speaker wire, which I did actually run 18/4

Then I realize that Valcom recommends just running regular telephone or data cable twisted pair

Do you think it will be a problem using the stranded 18/4

I’m assuming it’s going to still work it’s just I’m just wondering if it would’ve been better to run the regular Telephone/ Data



Thanks

JD

I'd think having the larger wire is going to have benefits due to the length of your runs. !8 gauge isn't THAT much bigger, but every little bit helps. If you're only sending audio, you're right. It doesn't make that much difference.

Valcom designed their system for phone guys using the wire they had- two pair 24ga CAT3. One pair for audio and one pair for power. The audio pair doesn't have really any restriction in length but the power does. If you go to the Valcom website they have a table of various gauges and permissible lengths and number of speakers. But since you say they are using multiple power supplies I don't think that distance will be a factor. If you do decide to use 18ga cable, no problem. Just make sure that it is two pair twisted.

-Hal

Valcom site has good resources, including a calculator for power over the cable.
For example, at 5 speakers over 700 feet, than 24 AWG is not supported. In this case, Cat 5 cable wouldn't be the best choice.
https://www.valcom.com/resources/calculators/power-pair-run-calculator

There is also a best practices PDF. It's pretty long (246 pages), but I skimmed through it.
https://www.valcom.com/resources/best-practices-installations

There is also a section on the AWG of wires when you twist them together to increase the size.

The main purpose of the pair twist is to reduce RF emissions and interference. I can't see any advantage of Cat 6 over Cat 3 in its case.
Valcom does recommend Cat 3, but I personally don't see an issue with 18/4. I've used 18/4 in the past and it's been working great.

The problem with CAT5or 6 vs standard cat3 is loop limits. CAT5 or 6 will cause you to run into loop limit issues. The same is when you use it for T1's etc. Self powered horns are self defeating over more than a couple that are reasonably close. That's why we have 25/70V amps.

I've never really liked self powered speakers but I do understand where they are coming from. As I said above, the system was designed for telecom guys and plenty have bought into it. I can't understand why, but many just don't understand a 25/70V (constant voltage) system. Not only do you run a single pair looped around to each speaker but the speakers are cheaper and generally the amp is also. It's really a no-brainer because what you can do is almost endless.

-Hal