M1XEP power consumptions


Active Member
The Elk current draw spreadsheet shows the M1XEP draws 330 mA, but it also has in the notes column "Power from P1216 Power Supply (included with M1XEP)". But when I put "1" in the quantity column, it adds 330 mA to the total. I always powered the M1XEP with the included wall wart, so I assumed it didn't draw any power from the M1G.

So if the M1XEP is powered by the wall wart, does it draw any power from the M1? If so, how much?

Is it recommended to power the XEP from the M1 (or a separate battery backed power supply, like the Elk P412)? I hadn't thought about it, but I guess if it's powered by the wall wart, and the power goes out, you lose the M1XEP, but the M1G, et al, keeps running. If the M1XEP isn't being used for central station monitoring, does it cause any problems if it shuts down? I understand that if the M1 is connected to other external devices via the LAN, those connections will be lost while power is out. My house will have a standby genset, so unless it fails during an outage, I shouldn't be without power for more than about 30 seconds.

I don't see how it could draw any power from the M1. It's connected via the serial port, no RS-485 connectivity. Recently, my M1XEP was down for a few months (power issues corrupted the firmware), and the M1 was fine.

I have a P412+battery dedicated for accessories, including the M1XEP, which does the job well.
If the M1EXP is powered using the wall wart or an aux power supply, then it draws nothing from the M1's power supply or battery.

The M1 will notice if the M1EXP loses power, but will keep running without it. If you need the M1XEP for CS communication, then I would power it with a battery backed aux supply rather than the M1's power. My goal is to keep the M1 running as long as possible on its battery, and the M1XEP just draws too much power to make that practical.