Cat5 network cable as power line for POP Z-Wave power supply for smoke detector POPE004001 (POPE004100) possible?

Hello, everybody,

the question is only indirectly related to openhab.
All electricians may feel addressed :slight_smile:
If somebody knows a more suitable forum, I like to ask there. Maybe someone with the appropriate competence will read along.

My ZWave network uses three smoke detectors from POPP (POPE004001). Since these need new batteries every 4-8 weeks, I would like to supply them with the appropriate power supply (POPE004100, 12VDC, 500mA, max.6Watt).

Where the smoke detectors are mounted, there is already a CAT 5 network cable.

Can I use the wires to transport the power from the power supply unit in the server cabinet to the smoke detectors? Should I connect plus and minus to more than one wire to avoid overheating?

I am happy about any suggestion.

Many greetings

Yes (although I wonder it requires 12V - most battery devices are 3.3-5 VDC).

Use a PoE switch or injector ? Just get one to deliver the voltage you need (standard PoE is 48VDC).


Blockquote Use a PoE switch or injector ? Just get one to deliver the voltage you need (standard PoE is 48VDC).

Thanks for the advise.

Only one two pin jumper is provided in the smoke detector housing for the connection of + and -. Unfortunately there is no space to install the counterpart to the POE Injector to separate data and power. Or is something like this not needed? Can I connect the two wires directly to the jumper?

If two wires can withstand the output power of the power supply I can use them directly. At the moment there is only the cable without plug and nowhere patched up.

You will need a POE injector to inject custom voltage like this one:

You will also need a power supply with adjustable voltage because the voltage will drop due to the length of the cable. Set your power supply to 12V, connect everything. Then adjust the power supply until you get the correct voltage at the end point.


Hello together,

POE seems to be the solution.

Then I summarize briefly for myself:

I patch the individual lines to the smoke detectors in the server cabinet onto a patch field.
Then I get single POE injectors ( for each smoke detector.

I then connect individual adjustable power supplies to the POU injectors.
This is necessary because the lines to the single smoke detectors are all of different lengths.

Now all I need is a suitable jumper for the connection in the smoke detector itself. Can anyone help? Does a photo of the smoke detector help?

Thank you very much for your support.

Yes please, photos of the outside and opened up.
With a zoom in on where the normal power would be connected
Oohhhh, fun. I love these kind of hack…

Ok, will post pictures tomorrow. lucky for me that you enjoy such hacks

I love the problem solving challenge. And there is always something new to learn.

This is quite abnormal in my opinion. I’m running fibaro smoke detectors and need to replace the batteries between 1.5 and two years. Did you change the report interval?

In addition I would think twice about supplying them with the power line instead of batteries.
What if you have a blackout or maybe broken cable? You would not notice it unless you’re OpenHab detects that the device is offline or you check it manually. But then you rely on your openhab that in all cases it will notify you about a smoke detector being not functioning.

In addition you’re changing the hardware of the smoke detector which invalidates its certification which can be problematic with your fire insurance.

The smoke detector has one purpose: Notify you if there is smoke/heat. And in order to do this properly it will notfiy you when the battery is low so that you can replace the battery early enough.

When your power supply by the cable breaks down, the smoke detector won’t do anything.

Hi Sascha,

thanks for yout advice.

Can you give me a source for that statement?


How should the smoke detector detect anything if it isn’t powered?

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This is a valid thought!
I have the same smoke sensors running with battery, and they run now since about 9 Month.
If they drain battery after 4 weeks, there is something wrong.
By the way, they are designed for external power feeding, so you don’t loose any certificate.

Oh, didn’t know that. Thanks for clarifying

Edit: So it seems that when connected with external power supply, the battery is being used as a buffer in case of a blackout. The manual states that even if you supply the smoke detector with external power, the battery must remain inside the smoke detector.

However i would try to figure out why the battery drain is that high before wiring it.

Hello, everybody,

so I like openhab: The community is just great. Many thanks for the support up to here and the different aspects to consider.

As announced the pictures:


I have three of these smoke detectors in use. Per floor (cellar, ground floor, 1st floor) one. On the 1st floor more will be added.

I have already turned off the meshing according to the instructions. The interval for communication with the controller should be set to 3h. Currently my default value for battery-operated Z-Wave devices.

As far as I know, the power supply supports the Z-Wave function and has nothing to do with the operation of the smoke detector. But I will order an original power supply and test it with the smoke detector that is mounted closest to the server cabinet. This is the shortest distance. The solution with the intermediate patch field also allows me to test the further distance. Then I can still decide if I want to use an adjustable power supply or if the standard power supply is sufficient.

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