Elk outdoor siren and strobe install

[amacphee]

After a recent break-in I have decided to add an external siren and strobe to hopefully get some eyes on my house during an emergency. I have purchased the Elk-1RT siren and the Elk-SL1C strobe.
My understanding is that I don't need a separate siren driver and I can run it off of Output2 (Is this correct?).
Can I run both the siren and the strobe in parallel off of Output2 or do they need to be separate. I am considering having them be separate since I could keep the strobe running after turing off the siren after 5 min of annoying my neighbors. Should I use Output3 for this or one of the J16 outputs?
 
Thank you for the help!
 

 

[RAL]

The Elk 1RT is a speaker rather than a stand alone siren, but yes, it can be driven off of Output2.  You will need to set global option 26 to "no" to have Output 2 produce sound to drive the speaker.
 
In this mode, you can't really connect the strobe to Output 2, as it wants to see a 12V power source.   You can drive it from the AUX power through a relay, such as Output 3, or a separate relay like an ELK 912 or 924.
 
One thing to keep an eye on is your total power draw from the M1 power supply, which is limited to 1 Amp, including keypads and other devices you have on the data bus or AUX power outputs.    The strobe requires 210 mA, so that's a significant part of the power supply's capacity.
 
Elk has a current draw spreadsheet to help you calculate the power.

 

[amacphee]

Awesome, thank you RAL. IT looks like I am only around 0.964 Amps with the strobe. I am assuming that driving the 1RT off of output 2 is already accounted for by the Elk?

 

[RAL]

You don't need to account for the power to drive the speaker, just the devices connected to the data bus and any thing powered from VAUX and SAUX.
 
0.96 Amps is pretty close to the maximum.  It's a good idea to leave yourself a bit more headroom and not go above 0.8 Amps or so.  Power consumption will be just fine in normal mode, since the strobe won't require anything.  But the last thing you want to have happen is for the system to crap out in alarm mode, when it matters most.
 
Seriously consider adding an additional power supply.  Something like the Elk P1215 or P112K would be more than enough to power the strobe.  Or, if you don't care about having a battery backup for the strobe, you could go with a P1216.

 

[amacphee]

I will take your advice. I assume I can use any 12VDC adapter around 1.5Amps? It looks like the elk one is almost $30 online and I can pick up a good one for $10. I assume I just place it inline on the output 3 relay feeding back into Comm and then NO onto the corresponding terminal?

 

[RAL]

I will take your advice. I assume I can use any 12VDC adapter around 1.5Amps? It looks like the elk one is almost $30 online and I can pick up a good one for $10. I assume I just place it inline on the output 3 relay feeding back into Comm and then NO onto the corresponding terminal?

 
Yes, if all you are going to power is the one strobe, then any 12VDC adapter that is rated at 0.5A or more should be fine.  All you need to do is wire it though the Output 3 relay so that the relay contacts switches the adapter output to the strobe.
 
Just realize that without a battery backup, the strobe won't operate during a power failure. 

 

[amacphee]

I have a very large battery backup for the whole system and network infrastructure. I will connect it to that. I decided to pick up a 2Amp power supply just in case I want to add more stuff. Thank you for your help!