How to wire Swann doorbell - can POE be cobbled to achieve power

[saltwater]

I have a Swann Video Doorbell Kit, WiFi Series, and one of the reasons I purchased it was because it could be hard-wired for power but can be run off a battery if necessary. During construction of my house, I ran both ethernet and a power cable to the doorbell location. Anyway, I'm hoping someone with a little electronics background can point me in the right direction. The instructions to use external power for the doorbell are a little cryptic for me. Below is an image of the wiring instructions for the unit from Swann. These instructions can be found here.



My first question relates to POE. Is it possible to cobble together a POE solution? I already have Unifi 500W 24 port POE switch. If so, what POE setting would I set at the switch?

If POE is not possible, or not recommended, I'm confused by the resistor mentioned in the above instructions. Surely there is a single charging unit that could do the job? If there are any links to suitable models that would be appreciated.

ps. In time I would prefer to replace this unit with a doorbell that is both POE and wired for data, that is, not relying on WiFi.

Cheers,
Steve

 

[alastairstevenson]

My first question relates to POE. Is it possible to cobble together a POE solution?

A standards-based PoE switch will only supply power if the 'PoE handshake' takes place.
And also it's nominally 48V DC - not the 16-24V AC that the doorbell requires.
The doorbell doesn't seem to be a PoE powered device.

I'm confused by the resistor mentioned in the above instructions. Surely there is a single charging unit that could do the job?

The requirements in the diagram are very clear and straightforward. And simple.
A 16-24V AC 1A supply and a 10 ohm 10W resistor.
I'm confused why don't you want to just provide what's required.

 

[saltwater]

The requirements in the diagram are very clear and straightforward. And simple.
A 16-24V AC 1A supply and a 10 ohm 10W resistor.
I'm confused why don't you want to just provide what's required.

I'm not an electronics buff but I don't understand why this part seems to be cobbled together, surely there is a 'one' unit that could do the job rather than building a supply unit.

 

[alastairstevenson]

Does the doorbell kit include the 10 ohm resistor?
It seems to be a common requirement, plenty of mentions in the doorbell threads.

 

[silencery]

If you don't mind taking a risk and if you're really intent on using cat 5, you can try putting the doorbell on the bench and hooking it up to a 12v DC power supply.

If it works, you can just install a DC power supply near your POE switch and use the CAT5 as low voltage wiring hooked up to the power supply until you get the POE doorbell in the future.

I've tried 3 wifi doorbells for now which all spec for AC power, but they all also operate on DC as well. That's how I'm operating my laview and dahua doorbells.

 

[saltwater]

Does the doorbell kit include the 10 ohm resistor?
It seems to be a common requirement, plenty of mentions in the doorbell threads.

No resistor or power unit with the kit.

I've noticed doorbell threads but they all seem to be 100+ posts for other brands. I'll peruse them tomorrow (Sunday night here in Oz).

Sent from my LG-H930 using Tapatalk

 

[saltwater]

If you don't mind taking a risk and if you're really intent on using cat 5, you can try putting the doorbell on the bench and hooking it up to a 12v DC power supply.

If it works, you can just install a DC power supply near your POE switch and use the CAT5 as low voltage wiring hooked up to the power supply until you get the POE doorbell in the future.

I've tried 3 wifi doorbells for now which all spec for AC power, but they all also operate on DC as well. That's how I'm operating my laview and dahua doorbells.

I was sort of thinking using the cat cable in this way. The length of cable to the doorbell is about 10-12 metres, is this a factor to be taken into account?

Sent from my LG-H930 using Tapatalk

 

[silencery]

By the way, i overlooked from your first post the doorbell supports batteries. In this case, it takes DC power for sure. The surefire way then, would be to figure out the battery voltage, match those specs with a power supply, and connect your ethernet to the battery lugs. Otherwise, if you can't do that for any reason, then you can try connecting to the lugs on the back of the doorbell (DC polarity won't matter).

For the length of wire, yes, there will be power drop. The amount will depend on resistance based on the quality of your ethernet. If you used cat6, it's generally higher gauge, but not all wires are the same. The only way to know if it will run stable will be to test.

That said, all my low voltage runs at least as long and they still work well. Doorbells especially don't draw THAT many amps.

 

[saltwater]

By the way, i overlooked from your first post the doorbell supports batteries. In this case, it takes DC power for sure. The surefire way then, would be to figure out the battery voltage, match those specs with a power supply, and connect your ethernet to the battery lugs. Otherwise, if you can't do that for any reason, then you can try connecting to the lugs on the back of the doorbell (DC polarity won't matter).

For the length of wire, yes, there will be power drop. The amount will depend on resistance based on the quality of your ethernet. If you used cat6, it's generally higher gauge, but not all wires are the same. The only way to know if it will run stable will be to test.

That said, all my low voltage runs at least as long and they still work well. Doorbells especially don't draw THAT many amps.

Thanks for the info. I'll report back on how things work out.

 

[tigerwillow1]

I find that external power hookup to be rather odd. I'm wondering if the 16-24 volt supply spec is to accommodate a standard doorbell transformer that would already be wired to the doorbell location? Taking the risk of slander, I consider these hardwire instructions to be engineering malfeasance. Since the transformer is required to be 1 amp, I'm assuming the doorbell could potentially consume an amp. If that's true the resistor will dissipate 10 watts. If someone were to stuff that resistor into a wall cavity, the potential to start a fire would be there. And why does it need such a strong power source? Are they using a shunt regulator? That would be dumb. I see from the manual that the internal battery is charged via USB. Is it ok to leave the doorbell hooked to USB constantly? Would that be sufficient to power the doorbell constantly? I didn't find any mention of these things in the manual. If a constant USB connection is acceptable and sufficient to power the doorbell, I don't see why you couldn't just power it with the POE switch connected to a 5 volt POE splitter, and a custom cable to route the splitter's DC output to a USB plug. The documentation for powering the doorbell is totally lousy.

I found one review that said a battery charge lasts about 3 weeks, suggesting a constant USB charge source would be more than sufficient to power it. But will a constant charge source cause a problem? The documentation should (but doesn't) say this. If I were hardwiring this thing according to the directions I'd make sure that 10 ohm resistor is located somewhere where it could get darn hot without creating a hazard. I'd also do a measurement of how much current is really pulled by the doorbell (should be way below 1 amp IMO), and put a small as feasible current value fuse into the circuit.

 

[saltwater]

Ok, so I've now hooked up external power to my Swann doorbell. Purchased the required items, 16-24 volt power supply and 10w resistor. I used the existing cat cable, at the doorbell end spliced two pairs, wrapped each pair together and then screwed to the doorbell. At the server end, the doorbell cat cable was already connected to a patch panel; that I left in place. I made up a 10 cm cable, splicing one end, wrapping two pairs together and at the other end terminated normally. Connected one wire pair to the resistor and then to the power unit. The other pair direct to the power unit. Used a patch cable from the patch panel to my newly created cobbled cat cable.

All works so far. The app in the phone tells me that the doorbell is charging, whereas before it was due for a charge.

Here is the cobbled cat cable connected to the power unit.



Here is my server rack. The yellow cat cable is the patch lead for the doorbell.



And a close-up of the cobble cat cable and power unit.



Question. Is it OK to wrap resistor in electrical tape?

 

[saltwater]

Update: The doorbell is now under constant power and the doorbell app reports 100% charge. There is no indication that external power is in use, you would not know that from the settings within the app.

I rang a security systems company about something else and as an aside I mentioned the fact I wasn't happy with a battery-operated video doorbell, that it wasn't instantaneous in reporting motion. He told me that that is because the battery must wake itself up, and that takes time, and then report motion. He explained that that is not the case with video doorbells connected directly to power. It made sense when he explained it. So, I'm thinking that my Swann video doorbell, still thinks it's operating from a battery, albeit, always charged, as the reporting of motion to my phone has not improved.

Anyway, what I'm saying is that the Swann Video doorbell is a piece of s... and can't wait to get something that can be POE powered and hard-wired for data.