New Transformer Humming Noise on Smart Doorbell 24 volt AC - How to fix this UK

[Dave2022]

Hello All,

Incase this reaches other non UK residents to confirm this doorbell has been fitted in England it regard to electricity distribution feeding the circuit

This is the first I've posted and I'm certain many on here will have a good explanation and remedy for this problem.
I've made the move to a smart doorbell from Hikvision replacing an old wireless battery doorbell.
I've installed yesterday and now noticed the transformer is humming. It's not too loud although annoying and want to check its not shorten the life of the doorbell transformer.

Setup as below
Main voltage 230v >

Transformer set at 24v AC >
(options 12,16,24v)

Door Chime
(factory transformer removed)

Cables down to doorbell

Included in the smart doorbell box was a resistor I've installed this on the side coming from the doorbell push signal to the chime. Unsure how to read the rating it has and the instructions make no mention of it even being used. Although they sell this as a stand alone smart doorbell with the option to add a chime (non hikvision branded) assume the resistor is required in the chime enclosure.

Hopefully I've include enough information and pictures

Doorbell > ebay
Transformer and enclosure > Screwfix 8707P & 32311
Door chime > Toolstation 60677
Cable already had is two core white flat flex 0.75mm

Thanks for taking the time, I look forward to hearing comments soon.

Cheers David

 

[Avo Mk8]

Seems to be a feature!
The Hikvision draws a small current all the time to give it the power it needs. It shouldn't be overloading the transformer, but others complain it makes their chime buzz. See: Hikvision doorbell cam causing chime to buzz - https://ipcamtalk.com/threads/hikvision-doorbell-cam-causing-chime-to-buzz.25641/
Post #17 in the link above says the resistor is only to be used with a digital (electronic) chime, but if yours works OK with the resistor in circuit as you have it, I'd leave it like that.
BG bell transformer is suitable for the Nest smart doorbell (and by implication others), so it should be happy with the load. I suspect the buzz may just be loose lamination in the transformer.

 

[brianmoooore]

There's a similar 'resistor' included with the Ring doorbell, but enclosed in heatshrink, so I couldn't see the markings on it. It measured zero ohms though, so I suspect it is a fusible link.