Bell transformer for Nest Doorbell

Gaz

I have a 2nd gen wired Google Nest door bell, which works perfectly but it is causing my indoor chime to sound very weak, like it isnt receiving enough power.

Google recommends an 8-24V, 10-40 VA transformer. Checking my transformer the label says 8-24V, 8VA. I assume the VA rating is insufficient and the cause of my issue but when I asked an electrician he said the 8-24V was more than adequate and he dismissed my concerns about the VA number. I'll be honest, I havnt a clue what VA means but if the number is smaller than Google recommends, surely this is possibly the problem ?

Anybody come across this before ?

10-10-20

Doorbell transformers are sightly tricky in that respect.

8-24VA indicates that the transformer has multiple outputs - one for 8VA, one for 16VA and one for 24VA.

The 8VA output will be at 4v and limited to 2A - hence it's VA (Volt times Amps) is 2A*4V = 8VA. Then 16VA will be 8V at 2A (8V*2A) and finally 24VA will be 12V at 2A. Example here:

If your chime is lower than before then that could signify one of a few things: damaged wiring, mis-wired at the bell, chime being too high current to work with the Nest, or that the VA selected is too low to provide the required current for the chime.

First thing to do would be check the VA on the transformer by looking at where the two output wires are wired into and also by checking the output voltage from the transformer. If the output voltage is 4v (8VA) then I'd move it to 16VA instead. Otherwise I'd put a multimeter over the output to the chime and check if the voltage is dropping significantly when the chime is rung. If the voltage drops off significantly then move to the next VA up.

Gaz

Its using the outter connectors, so thats 24V which is 48VA ??

10-10-20

https://www.boards.ie/discussion/comment/121922217#Comment_121922217

That would be correct - 24v at 2A. The Nest is rated for that voltage. I'd check the wiring on the chime and the voltage as mentioned.