Elk M1, motion sensor, low voltage

[Longhorn84]

Can someone help me figure out how to wire the low voltage power from my motion sensor to my Elk M1 Gold (I can't post links yet but it's the [background=rgb(251, 251, 251)]40 x 40 PIR/Microwave w/Pet Immunity from Smarthome)[/background] I will have three total. I can't tell if I can wire them all into the actual panel or if I need batteries. I know stupid question but hopefully someone can help real quick and set me straight. Thanks!

 

[Longhorn84]

Reading the manual helps. I guess just running the wires to the +VAUX is the way to go. If I add glass breaks later, how do I know when I'll exceed the amps on the VAUX?

 

[chrisexv6]

The manuals for your sensors should give you the amount of current draw (sometimes listed as "Max draw" or "draw in alarm", etc)

Take the max amount for each sensor, add it up and I think it needs to be under 1A for the panel to support it directly.

I personally went with a separate power supply for all of my motions and glassbreaks, saving VAUX for my smokes, heat and CO detectors (and the associated reversing relay)

And, you need backup *batteries* regardless (maybe one, maybe two depending on how you setup your smokes, if any). Your question will be if you need additional power to handle all of the sensors. There is a section in the M1 manual about how to add more power directly to the mainboard vs a completely separate power supply.

 

[Longhorn84]

This was very helpful, thank you. The motion sensor draws 20mA max, and the Elk can take 1A before things go bad. The Elk has a big backup battery so I think I'm good there. For your smokes, heat, and CO detectors, how do you plug them all in to the little clip? Seems like you wouldn't be able to fit three power lines in one slot?

 

[chrisexv6]

Smokes are on a loop, so only 2 conductors there.

Heat detectors are a separate loop, but they are mechanical so no power required.

1 CO detector (right now) is connected to an Elk PD9 which is run off my external power supply. I have each CO detector as its own zone so that would be another 2 sets of 2 conductors each currently connected to VAUX. I think I just ran a short wire off VAUX and then used it as a pigtail to tie with the smokes and CO power feeds. Not the most elegant solution (see below) but it works.

In reality all you need to do is pick up a couple barrier strips from Radio Shack, etc. Put a small jumper (or jumper wire) between each set of screws on the blocks, then run a single set of conductors from VAUX + and - to the first set of screws on the blocks. Then connect as many things as you like, you are only limited to the number of positions on the barrier strips (but also keep in mind the current limits off VAUX).

Also in the Elk manual are the specs on how much battery time is required to keep it UL approved. If you connect your smokes to the panel, you are required to have 24 hours of backup. Without smokes, only 8 hours.

Im still torn on the way I prefer. While I think its more reliable to have mission critical stuff powered directly from the panel, having them powered completely from a separate supply also has its advantages (i.e. smokes can run even with the alarm panel down....while it wont fire off all the sounders at once, you will at least get the sensor that detected smoke going off)

 

[Longhorn84]

gotcha, that all makes sense. so your smokes don't have a battery backup or anything? I guess the likelihood of your panel being down for an extended period of time, and having a fire, and not being around to notice it would be pretty small.

Not sure why I hadn't even considered using a wire nut, is that what you mean by pigtailed or did you actually just wrap them around each other? For now I'll use your barrier strips idea and consider the PD9 down the road if necessary. Really appreciate the help!

 

[chrisexv6]

I used Elk gel-filled b-connectors just because I had a bunch. Wire nuts would work just fine too (just make sure you size them correctly...22 ga wire isnt very big). The barrier strip setup is more elegant anyway, so just feed one red and one white into separate barrier strips, jumper the screws on one side of the strips (radio shack even sells the jumper pieces if you dont want to make your own) and you are good to go

As far as the smokes, since they are powered off the main board whatever backs up the main board backs them up as well. Just to be sure I have TWO batteries connected to the mainboard instead of the fairly standard 1. The smokes and CO (and whatever is on the data bus) takes up so little 2 batteries should last a very long time.

 

[wuench]

I broke out the power using a barrier strip. Pics in my sig....

 

[Longhorn84]

Wuench, i checked out your system yesterday after I googled "Elk M1G" pictures, you're number three! I love the setup, a bit OCD which is right up my alley!

So you would recommend the ELK-P412 over like a regular UPS for router/external hard drive/ethernet expander?

 

[wuench]

Actually if I had to do it again I would look into a P212S. The P212S is managed and the P412 is not. I don't get any notification of issues, like battery failures. I work around it by replacing my battery when the main one goes bad...

I don't use the p412 for zone power, just for the M1XEP, router, modem, etc. When I say I broke out the power I mean the barrier strips mounted right under the M1 (1 is power the other is for audio breakout). I also ran power from there down to some PD9s mounted next to the M1XINs but that is kind of overkill...

 

[Longhorn84]

So how do I practically "plug in" the modem, etc to the P212S? Do I have to cut off the end of the power cord that came with the modem and connect the wires that way or do you run the output cables to an outlet or something? Maybe I'm missing something. Thanks for the help.

 

[newalarm]

The p212s is a power supply. If you exceed your 1Amp on the main board, you will need to add one of these. There are two blocks for power that you can use to power devices, but not more than 2amps.

Not sure what you mean by modem....

 

[wuench]

Yeah, that's what I had to do, cut of the end. Mostly because there seems to be no rhyme or reason for barrel connector standards. I went to radioshack to try to find a replacement connector and the guy pulled out a massive keyring of connectors to try to match them up and still couldn't come up with the perfect fit. And the devices you plug into the PS have to be 12V. It's up to you, or you can do a UPS if you want to deal with the wall warts.

 

[tmbrown97]

It's definitely more efficient all around for 12V devices to back them up directly off a battery with a power supply like mentioned above than it is to power an inverter to bump the voltage up to 120VAC just to then drop it back down to 12V again; if you have mostly 12V devices, that's the way to go. Nowadays we're also seeing a lot of 5V devices, but you can use a step-down and still keep the same power supply if you wish.

 

[Longhorn84]

Ok, I'll need to check everything at home before I move forward. I think at this point all I have is a Uverse router, elk ethernet expander, and a ethernet hub that need to be plugged in to a battery backup in case someone cuts my power and then breaks in (my alarm is monitored through the internet).

So I would theoretically purchase the P212S, an extra battery, an elk transformer, plug the 212s into the transformer, the 212s into the battery, cut the end of the wires for the three devices currently plugged into a wall socket and splice them into the p212s? The Elk is on it's own battery, then these three will be on a battery backup, so if the power is cut, I should have the elk, ethernet expander, internet, and all other ethernet devices in working order for a short period of time. The only thing I need to check is the voltage on the three devices currently plugged into the socket, they need to be 12v?