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How to wire 2 "smart" doorbells to the same chime?

Postby itm60 » Sat Aug 14, 2021 10:39 am

I have a Siemens Gigaset HC450 door intercom, installed with a Friedland D107 chime. The Siemens Control Unit is powered by a 12VAC 1A transformer, and the chime by an 8V 1A transformer.
I also have an Ezviz Smart Video Doorbell, powered by a 12VAC 1A transformer. I was wondering if it would be possible to connect this video doorbell to the same chime as the Siemens system, as the Friedland chime has 2 spare terminals - the Siemens system is connected to the 0(F) and 3(T) terminals, but the 1 & 2 terminals are unused.
Attached are the wiring diagrams for the two doorbells, and the same for the Friedland D107 chime which I'd like to connect the 2nd doorbell to. TBH I don't understand the difference between the two wiring examples in the Friedland D107 diagram.

Could anyone advise:
1. (How) can I connect the Ezviz video doorbell and transformer to the existing Siemens/Friedland setup
2. Should I retain separate 12VAC 1A transformers for the Siemens and Ezviz doorbells, or would it be feasible to power them both from the same transformer?
DB1C and HC450 wiring-medium.jpg
Friedland doorbell chime connections.jpg
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Simply Build It

Postby Mr White » Mon Aug 16, 2021 9:56 am

I would suggest that for ease of installation and to avoid problems in the future you install the devices as the diagrams show, not interacting with each other.
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