Getting Ethenet Module power from M1G?

[HoustonFirefox]

Hi all,

I currently have a new M1G installation and the Ethernet Module for it just arrived. As I only have one outlet in the HA closet for the M1G is it possibly to do away with the "wall wart" for the ethernet module and have it supplied with 12V from the M1G itself?

I know it would involve cutting off the wall-wart power adapter but it would make for a cleaner installation along with the convenience of having the ethernet module backed up by the battery in the M1G.

Any upside/downside to this line of thinking?

Thanks

 

[Digger]

I do not beleive that the M1 can handle the ethernet module connected directly to it for power.

The M1XEP is rated 300 ma. The M1 can handle about 500 ma with 2 8 aH batteries for 24 hours of battery backup (required by NFPA if you use it for fire). Since each keypad is at least 65 ma (depending on backlight etc) and you will have other devices you are eating away at your aux power.

I am buying a decent size UPS and plugging in the M1, the M1EXP, the router, and the cable modem. I want to get 24 hours that way and then I would still have the additional 24 hours of the M1 itself (wont be able to transmit over the ethernet at that point). Once I exceed the 500 ma aux power of the M1 I will add a supplemental power supply (and connect the negative together). the supplemental unit will have battery backup as well.

 

[electron]

I personally would get one of those Elk PD9 power distribution modules, so you can remove most of your wall warts (since most are 12V), and use a seperate battery to back that up. This is what I did for most of my 12V stuff, and works pretty well.

 

[HoustonFirefox]

Thanks for the info guys! Based on what I see here I'll probably go with the ELK-PD9HC and get a large (2.5amp) wall-wart to power it.

Thanks again for the info!

 

[Spanky]

The M1 can power the M1XEP directly. Pay attention to the total current drain from the M1. If you are doing a UL home fire installation, UL wants 24 hours of system operation on the battery (two 8 amp hours batteries required) and you are therefore limited to about 500 milliamps.


The power supply can handle 1.5 amps. The controlling factor is the amount of standby battery time when the power fails. With more current draw, the shorter the amount of standby battery operation upon AC (mains) power failure.




trivia: The US market refers to the power from the power company as "AC Power". Many other places in the world refer to this as "Mains Power".

 

[Digger]

The UL requirement for 24 hour battery backup comes from the NFPA 72 requirements if I remember correcttly so regardless if it is a UL installation or not you may wish to have 24 hour battery backup if you are using it for fire alarm functions.

Ok break over back to the grind..........

 

[HoustonFirefox]

Spanky,

Thanks for the help! I'm glad to see that the Elk M1G can handle a load like that. As an aside, the Elk transformer is plugged into a 450va battery backup already (bought it before I noticed that the M1G cam with it's own battery). Since the Elk transformer is "isolated" from the mains then it should last longer than being plugged directly into the wall (we get nasty thunderstorms here in Houston).

Although not the most efficient method of adding run time, the 450va UPS should power the elk transformer for quite some time before the Elk's own UPS has to kick in. Any good/bad thoughts about this setup?

Added three more zones to the system yesterday. Broken & bruised from crawling in the attic but feel more secure already

Thanks

P.S. Just turned a friend onto the Elk M1G yesterday, he was so impressed he placed his order today 8)

 

[dscline]

Any good/bad thoughts about this setup?

The only thing I can see is that you lose the ability to have instant notification of a power outage. The panel won't "know" that your power is out until the UPS is dead. Personally, I'd rather put the money into an extra battery for the panel, than getting longer run time by essentially putting back-ups in series. I don't know how widespread this is, but here, code requires that the main disconnect be on the outside of the house (so the fire department can easily cut power). Of course, that also means that anyone can easily cut your power, without even having to touch any wires. I kind of like to know that I can be notified when my house loses power.

 

[Digger]

You can still have notification when the house loses its ac but still have the panel and teh router, modem, EXP etc on a UPS as well as the normal battery backup for the panel (which will also be plugged into teh UPS. using this method I will probably get a few days of backup depending on the size of the UPS.

My setup will have a relay energized by house ac. When the ac drops out the relay will trip a zone set for ac supervision of the house. I will get a notification that the house ac is out.

 

[dscline]

True, but it still seems simpler to me to just put more battery in the M1.

 

[Digger]

The M1 can only handle a max of 18 Ah battery if I remember reading it correctly. That said and you need 16 Ah of battery to get 24 hour battery backup with a 500 ma load I need more since teh EXP alone is 300 ma and I have lots of other devices added (3 keypads, 2 zone expanders, 1 retrofit hub, 7 smokes, 3 CO's, one RF receiver, and about 8 motions already).