Nest Doorbell Advice - voltage on bellbox & cable guage

rcanpolat

Hey folks,

I want to install a nest doorbell at my property and I have a few questions I'm hoping somebody can answer.

My transformer is a 8/12/24 -8va transformer and it's outputting on the 8v line.

My bellbox has a stamp on the inner shell saying 9v (reference image: https://imgur.com/2steLdd ) and I'm guessing that is a reference to the voltage and not some manufacturer product code.

I understand the Nest requires an 8va transformer with 12-24v so I know I need to rewire the transformer to output 12v which is fine, I can do this, but my 2 questions are as follows:

1: will the bellbox be ok with 12v coming in since it's stamped as 9v? It's one of those analog dual bell "ding dong" type of rings, I don't know if that's relevant.

2: it's a new house so the electrician has used the cat6 cables from the transformer to the bellbox and he has used some other cable out to the button press. He only used a single strand for the +/- for the transformer. If I am bumping up to 12v is a single strand sufficient? I don't want to melt any wires behind the walls if the voltage is upped. It's decent ethernet single core copper but it's still quite thin. Not the cheap plated stuff from china.

2011

Your transformer is suitable for your Nest. The 24VAC output is best suited.

The existing chime (bellbox as you call it) you have should not be connected to a volatge higher than it is rated for.

My solution: I binned the chime. It is surplous to requirements as all of my Google home devices and smart phone notify me when someone presses my Nest Hello.

2011

........and the selected cable is fine.

rcanpolat

I've been looking online at some chime boxes and some of them seem to be 9v DC, 12v AC.

I'm curious now if mine operates like this but it just happens to be undervolted to 8v ac but is still functioning.

I would prefer to keep my actual chime box because it's a sound familiar to my ear for the last 32 years and I genuinely like the sound of it. It's pleasant to the ear

astrofool

Essentially you need a chime like this (works at 8-16v)
https://www.amazon.co.uk/Friedland-Own-brand-packaging-D117/dp/B0001NPYZ2/

And a transformer like this:
https://www.amazon.co.uk/24V-8VA-Module-Bell-Transformer/dp/B07K8NKW3J

We have the Nest setup at 16v and it works very well, and it was nice to keep the doorbell.

Chimes are fairly simple, so may work anyway, but not worth the risk of burning it out (and damage that could ensue) by overvolting it.

The nest also comes with a little module that goes inside the bell housing (likely a resistor, but I haven't opened it up) to allow the bell to be connected properly.

2011

astrofool wrote: »

Essentially you need a chime like this (works at 8-16v)
https://www.amazon.co.uk/Friedland-Own-brand-packaging-D117/dp/B0001NPYZ2/

This should not be used if the 24V transformer output will be used.
The chime has to be rated for the applied voltage.

astrofool

2011 wrote: »

This should not be used if the 24V transformer output will be used.
The chime has to be rated for the applied voltage.

Yes and it can be used at the 16V output that the transformer can provide and the Nest Doorbell supports.

It looks like the European version of the Ring Doorbell Pro also now supports 16V and could be used with the chime I linked above (though I have not ran this setup myself).

2011

astrofool wrote: »

Yes and it can be used at the 16V output that the transformer can provide and the Nest Doorbell supports.

Speaking from experience the Nest doorbell performs better when connected to a 24V supply.
There is plenty online about this. This is why so many people want to do this.

astrofool

2011 wrote: »

Speaking from experience the Nest doorbell performs better when connected to a 24V supply.
There is plenty online about this. This is why so many people want to do this.

Can you define "performs better" ? The internal components of the device are likely working in the 1.6V - 5V (highly likely 5V as it also works off micro-USB) range, the reason most of these started at 24V is because that's more of a standard in the United States which was the first market they released in rather than a different voltage being better or worse.

edit: the indoor power adaptor which uses a plug seems to supply at 18V/500mA for reference.

2011

astrofool wrote: »

Can you define "performs better" ?

Less prone to disconnecting from Wifi.

Also the output voltage measured on the terminals on the secondary side of the transformer will be higher than at the door bell. This volt drop is proportional to the resistance of the conencted load. Therefore the lenght of the cable run is inportant as well as the resistance of all connected loads including chime(s). So with longer cable runs this may be an issue.

This does not mean that it won't work at 16V, its just not what I would do given the option.

the indoor power adaptor which uses a plug seems to supply at 18V/500mA for reference

It is also supplied with a short lead thus limiting the volt drop.

2011

From the second post on this link, I bolded the most relevant part:

When I bought and installed my Nest Hello doorbell about a month ago, I also upgraded my older doorbell transformer to a 16V 10VA that I purchased in town. Unfortunately, that one still didn't work quite right for me.
I have 2 mechanical chimes that are in parallel off my front door. One chime is in the main foyer and I put another repeater chime in my finished basement a few years ago so that I would hear it when i was down there.

With the 16V 10VA transformer, the amperage was not enough to run the Nest Hello doorbell and both mechanical chimes. The Nest Hello would chime, but the 2 mechanical chimes would just barely "ding" but not "ding-dong." Apparently the Nest Hello draws about 8 amps and a 10VA rated transformer is just barely enough to run the Nest doorbell!
I ended up ordering a 24V 40VA transformer online. The big home improvement box stores don't carry these larger doorbell transformers in the stores. Once I installed the higher rated transformer, everything worked as it was supposed to! The Nest doorbell stays online and has a great HD picture and my 2 chimes are louder now and "ding-dong" properly.
I don't notice that the transformer gets very hot...it stays relatively cool. The components only draw the amps that they need. It's better to have more than enough power for them to operate normally than not enough.
With these new video doorbells, the minimum rated transformer needs to be at least rated at 16V 30V

rcanpolat

My next issue is finding an analog "ding dong" style chime that takes 24v.

Any suggestions?

micks_address

i wouldn't worry to much about the chime.. our old one was / is rated for 16v and hasnt given any issues since we got nest installed.. id recommend keeping a chime as it will be independent of wifi/broadband issues... bell still rings.

rcanpolat

micks_address wrote: »

i wouldn't worry to much about the chime.. our old one was / is rated for 16v and hasnt given any issues since we got nest installed.. id recommend keeping a chime as it will be independent of wifi/broadband issues... bell still rings.

Since yesterday's post I've managed to identify my chime and it is rated for 9-12v. I don't fancy overvolting it to 24v.

My transformer does not an a 16v output. It does have a 24v so for the sake of not having to pay a qualified electrician to swap out the transformer in the fuse box I'll most likely have to run on 24v since folk say 12v drops wifi a lot, hence I need to find a 24v chime.

astrofool

2011 wrote: »

From the second post on this link, I bolded the most relevant part:

I don't like to rathole, but the issue there was more likely to do with the supplied amps from the transformer rather than the voltage, especially with 2 chimes (highly likely that person has over-volted them) on the same circuit, I'd imagine that a transformer like this running at 12V would have no issue at all:
https://ie.rs-online.com/web/p/mounting-accessories-kits/7349028/

For context, we have about a 15M run of wire, with a 16V chime and nest doorbell, and haven't seen any WIFI or power issues since install.

Pasteur.

astrofool wrote: »

I don't like to rathole, but the issue there was more likely to do with the supplied amps from the transformer rather than the voltage, especially with 2 chimes (highly likely that person has over-volted them) on the same circuit, I'd imagine that a transformer like this running at 12V would have no issue at all:
https://ie.rs-online.com/web/p/mounting-accessories-kits/7349028/

For context, we have about a 15M run of wire, with a 16V chime and nest doorbell, and haven't seen any WIFI or power issues since install.

As 2011 rightly pointed out if there's a voltage range you're better off at the high end of it at these extra-low voltages

You can experience problems at the lower end

astrofool

Pasteur. wrote: »

As 2011 rightly pointed out if there's a voltage range you're better off at the high end of it at these extra-low voltages

You can experience problems at the lower end

As these are generally built around USB standard (5v), there should be no advantage to a higher voltage as they will internally transform it down to that level (which is also why a firmware update was able to "add" 12V support), most high powered micro-chips operate at under 1.5V, with 3.3V also being quite standard.

Pasteur.

astrofool wrote: »

As these are generally built around USB standard (5v), there should be no advantage to a higher voltage as they will internally transform it down to that level (which is also why a firmware update was able to "add" 12V support), most high powered micro-chips operate at under 1.5V, with 3.3V also being quite standard.

Maybe I was generalising

I'm not familiar with any of this particular equipment

astrofool

Pasteur. wrote: »

Maybe I was generalising

I'm not familiar with any of this particular equipment

I do remember back in my earlier days, I had fixed an issue on a Pentium 150mhz computer an electrician friend had, I think they ran at 5V back in 1995, I was telling him about the Pentium MMX coming out soon, but it wasn't compatible because it ran at 3.3V, and his first thought was to manually update his motherboard accordingly (the change also required a new chipset and micro-code updates, I'm sure some enterprising individual actually managed this, probably in China).