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Electricians: Low voltage/POE questions

This topic can be found at:
https://sigforum.com/eve/forums/a/tpc/f/320601935/m/3320065644

September 02, 2018, 03:26 PM
ryan81986
Electricians: Low voltage/POE questions
So here's the long and short of it.

I'm currently building/have built an alerting system for my fire department. The unit is powered by a radio that senses the dispatch tone and trips a relay and broadcasts the radio audio via Ethernet to powered speakers in the bedrooms and general areas of the station.

The next step in the process is to activate lights to turn on when the alert goes off via the same trigger and a separate relay. I had originally thought of using X-10 home automation devices and just swap out the switches in the bedrooms to have the lights turn on. However since the X-10 broadcasts the signal through the building's wiring I'm not sure that would work as the building is around 3k sq'.

Another option is to use low voltage LED lighting, either 12V or 24V, 12V being the most likely. The rooms that would have the lights are appx 20-30' from the main power supply. The max mA for the lights that I'm looking at is 700.

What I'm wondering is, would I be able to get away with using POE, the existing Ethernet running to the speakers is only using 2 leads for the audio and 2 for the power, so there are leads left. Or I could use landscape wire or something similar. The wires would be run only in unfinished attic space.




September 02, 2018, 05:39 PM
zoom6zoom
X-10 is obsolete, somewhat unreliable (no acknowledgment of signal received on many units) and many part numbers are no longer available.

Check out Global Cache. We used this in a number of control scenarios like yours. I have one at home using a wireless connection to control relay outputs. There's a boatload of choices for control and connection type.
https://www.globalcache.com/products/itach/




I have my own style of humor. I call it Snarkasm.
September 02, 2018, 06:32 PM
ryan81986
The problem is our town's network isn't very user friendly (And it goes down a lot)

Plus I need something that has it's own controller that can be triggered either by a contact closure or by low voltage being applied to it.




September 02, 2018, 07:39 PM
ryan81986
I'm starting to lean more towards dedicated LED lighting, just for the versatility of it.

Operate the trigger with an ELK 960 relay, the ELK 960 would trigger a BOSCH style relay since the relay in the ELK may not handle more than a couple amps.

12V power supplied by a Duracomm power supply

Mount one or two of these in the bedroom:
https://www.superbrightleds.co...40-lumens/1681/3980/

As well as one in the day room, and maybe a few red modules in the hallway.

Wiring would be 18/2 CL2 rated LV/thermostat wire.

Thoughts?




September 03, 2018, 01:08 AM
jprebb
You ever heard of MACH Alert fire station alerting? This is their bread and butter. MACH Alert

JP
September 03, 2018, 08:38 AM
ryan81986
We've looked into standalone systems but the problem is that they are usually in the 10s of thousands of dollars and require a tie in or additional equipment in the dispatch center. This system to date has cost us only around $500 and works independently from our dispatch center.




September 03, 2018, 08:45 AM
striker1
quote:
Originally posted by ryan81986:
I'm starting to lean more towards dedicated LED lighting, just for the versatility of it.

Operate the trigger with an ELK 960 relay, the ELK 960 would trigger a BOSCH style relay since the relay in the ELK may not handle more than a couple amps.

12V power supplied by a Duracomm power supply

Mount one or two of these in the bedroom:
https://www.superbrightleds.co...40-lumens/1681/3980/

As well as one in the day room, and maybe a few red modules in the hallway.

Wiring would be 18/2 CL2 rated LV/thermostat wire.

Thoughts?


The Elk 960 form C relay contacts are rated 7A@30VDC or 10A@125VAC. The example LED bar you linked draws 2.25A @ 12VDC (powered from mfgr-supplied transformer). So the 960 relay by itself will only be able to handle two, *maybe* three. You’d have to determine actual current draw. You may need two 960 modules.



RB

Cancer fighter (Non-Hodgkins Lymphoma) since 2009, now fighting Diffuse Large B-Cell Lymphoma.


September 03, 2018, 10:54 AM
ryan81986
That's why I was thinking maybe have the 960 power a Bosch style relay that draws its power directly from the 20A power supply.




September 03, 2018, 05:09 PM
sig2392
Honeywell as well as other makes a low voltage trip 120 volt line relay.

Around $80, should do what you want.