I purchased a rechargeable battery operated Ring 3 doorbell hoping the momentary switch would trigger both the Ring components (Alexa units, cell phone app) and also ring all the home phone extensions through the KX-TD160 phone card. I knew there would not be enough power over the Cat5 attached to the pre-existing door speaker to run the system and the Ring required AC power and not the VDC power presumably coming from the phone system. I contacted a commercial phone guy I have used in the past and he said he never did a connection like this. There is a little on the internet about putting in some 24V relay in-line with the circuit but those have shown an AC transformer which I don't have in this set-up. Ring makes another model that has PoE which I presumably could use if needed. I know that if I call in a low voltage wiring guy who specializes in surveillance they will refuse to touch anything that connects to a commercial phone system they don't understand and it is not clear that most phone guys would know the other end of the business especially if it involves adding in a relay. Does anyone have guidance I could share with my phone guy to get this done or know of someone in the Chicago areas (30 miles NW of city) who would have experience connecting a modern video doorbell to a legacy key system? The house is large and having extensions ring everywhere would be helpful and that is why I'm not just adding a standard doorbell to my entrance foyer. Thanks in advance.
I have no idea how the Ring doorbell works, matter of fact I hate anything Ring or Nest. That said, all you need to trigger the phone system doorbell is a short between tip and ring on the extension you have programmed for the door phone.
So, since Google is my friend, (and yours too) I looked up the installation instructions for the Ring 3. Apparently you simply replace your existing doorbell button with the Ring (assuming your existing doorbell is powered by a 24vac transformer) and you are good to go. It steals power from the doorbell circuit so you don't have to recharge the battery every so often. Hmmm, maybe they aren't so bad after all.
So what this means is if you have an existing doorbell all you have to do is replace the chime with a relay having a 24vac coil and then wire the tip and ring from the phone system port to the NO contacts. You can even leave the chime in place, put the relay inside of it and wire the coil across the chime solenoid.
If you don't have an existing doorbell, install wiring, transformer and relay like you did.
-Hal
Wow, never thought of that. Cheers Hal!
Hal, thanks for your comments. There is no traditional existing doorbell or transformer and that is one reason I chose the Ring 3 since I thought charging the battery every six months was a better plan than trying to pull new transformer wiring. Ideally I was hoping to connect something between the Ring 3 terminals and the wire pulled to that door phone location but I am open to other workable solutions. If there is no pipe run from the doorbell to the key system (and why would there be with low voltage wiring) it may be difficult to run additional transformer wires to that site. The thin unused Cat5 wires would probably be inadequate. There is a shitload of phone cabling and AV cabling installed by the original owner that terminated by the KSU. A phone guy might feel comfortable using the original wire to pull others that could be connected to a transformer but if my guy showed any enthusiasm to solve this I would have heard from him by now and not be posting myself.
You are going to have to run wiring to the doorphone location anyway. All you need is one pair. Get it to the phone system location using new or existing and put the transformer and relay there. CAT5 24ga wiring will be fine.
If you can't find a security or phone guy to do it try some electricians.
-Hal
The important thing to remember is that the door phone connections on the Panasonic system will respond to a momentary short (like a button push) across the pair to start all of the programmed phones ringing for one full ring cycle (about 15-20) seconds. As Hal mentioned, a slave relay that places this short across the door box input on the phone system is all that is needed. This relay and connection can be placed anywhere, and a spare pair in the cable feeding a nearby phone can be utilized for this purpose.