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Went to Home Depot the other day to fix my doorbell and bought this: https://www.homedepot.com/p/Hampton-Bay-16VAC-30VA-Transformer-Compatible-with-All-Video-Door-Bells-HB-130-03/309792479

It's: "output: 16 VAC/30 VA" but all the "regular" doorbells they had were 12 volt. Is it an issue that the voltage doesn't match? I know it's low voltage and probably not a big deal but I'd rather do things correctly if I can. That was the only transformer they sold but I see on their website they have this: https://www.homedepot.com/p/Newhouse-Hardware-Wired-16-Volt-AC-10-Volt-A-Doorbell-Transformer-for-Wired-Door-Chimes-UL-Class-2-Certified-16TR/206973663

That one says 10 volts which still doesn't match the 12 v doorbell. Kinda weird to me that nothing matches the "standard" 12 volt doorbells.

Everything I google is all "ring doorbell, ring camera, ring, ring ring". I just want a regular doorbell. Congrats to Ring I guess for their market penetration but does anybody know?

Thanks very much.

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  • I am confused. Do you have 12 V door bell, and not a Video door bell.
    – Traveler
    Sep 10, 2022 at 7:06
  • Yes, just a regular 12v doorbell. Just a button that rings, that's it.
    – John
    Sep 10, 2022 at 7:48
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    What exactly is wrong with your doorbell? Are you trying to fix it? Replace part or all of the system (transformer, button,chime unit)?
    – Armand
    Sep 10, 2022 at 9:11
  • The transformer is dead (I think it's a few decades old). Also the doorbell is slightly broken (button cracked) so I plan on replacing that as well. It's old/original equipment.
    – John
    Sep 11, 2022 at 9:18
  • Second one is also 16 Volts. At 625mA, as opposed to 16V at 1875 mA for the first one. Try 12V doorbell transformer in a general search engine if you want 12V They exist, whether or not Homely Despot carries them.
    – Ecnerwal
    Sep 11, 2022 at 18:26

2 Answers 2

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You're confusing Volt•Ampere ratings with Volt ratings, for two transformers with the same Volt ratings and different Volt•Ampere ratings.

16 VAC 30VA is 16 volts alternating current, at 30 Volt•Amperes = 1.875A, or 1875 mA

16 Volt AC at 10 Volt-A is, of course, exactly 1/3 the amperage at the same voltage. 0.625A or 625mA - thus, 1/3 the power of the first one.

Neither one is 10 volts (or 30 volts) - both are 16 volts.

If your doorbell is 12VAC and picky about it, plenty of folks actually have 12 VAC doorbell transformers. Search, and ye shall find. Quite possibly not at Big Orange, which is a lousy excuse for a hardware store, or electrical supply house.

In general, you should match the voltage your doorbell (or whatever) asks for, and meet or exceed the VA rating. The voltage is fixed, the current is how much it can supply, and it can supply anything less than that, depending what the doorbell needs. Oversizing the VA mostly wastes money, and a little bit of standby power loss, so don't go crazy with it. You should look at the specs for the doorbell you actually have in your house if you are only replacing the transformer. Don't go by the specs of the burned out transformer, since it may have been wrong, if it burned out. They usually don't burn out if correctly specified. 50+ year lifespan...

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Safety Note: The doorbell transformer is wired to full dangerous 120V house current! Shut off power to its circuit and verify that power is off with a multimeter before working on one.

To answer part of your question, let's break down the terminology for a doorbell transformer:

In your example "16V 10vA transformer for powering 1 door chime"

  • 16V (AC) means the transformer converts house AC (120V) into 16V, still AC. 16V should be plenty for a traditional chime, although may be too low for a modern smart doorbell -- see smart doorbell's specific requirements.
  • 10VA means 10 Volt*Amps and is a measure of the total power it can supply (like watts). In this case, it roughly means that the transformer can supply up to 10VA/16V or about 0.625 amps at 16V. That's not a lot, again should be OK for a traditional chime but too low for modern smart doorbells.

If replacing a doorbell transformer, just match the new one for output voltage and make sure it is rated for at least as many VA as the old one.

If replacing both chime and transformer, check the voltage range and VA requirements of the chime and make sure your new transformer voltage is in the voltage range and that the VA rating is at least as large as the chime requires.

Regarding a traditional chime, search for "wired doorbell chime" and you should be able to find one easily. One I found listed power required as

Compatibility: use with a 16-Volt/10-VA or 16-Volt/15-Volt A transformer (not included) when connecting to a regular doorbell

Edit: Note re: doorbell push button - I would expect an unlit doorbell push button (no circuitry, just a mechanical switch) that was designed for 12V to work fine with 16V.

Safety Note: The doorbell transformer is wired to full dangerous 120V house current! Shut off power to its circuit and verify that power is off with a multimeter before working on one.

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    So that's my question, it doesn't match. The transformers they sell at the store are 16 volts, whereas the doorbell buttons are 12 volts. I looked online and they sell a transformer that is 10 volts. Either way, they don't sell a 12 volt transformer. So is I do a 16 volt transformer with a 12 volt doorbell button, is that ok? Or would it be better to do a 10 volt transformer with a 12 volt button? Just confusing how nothing matches the doorbell buttons they sell.
    – John
    Sep 11, 2022 at 9:20
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    @John the replacement wired doorbell buttons I found listed at my Calif "big orange" store were described as "this push button works with most 16-Volt hardwired doorbell systems". I would expect an unlit doorbell push button (no circuitry, just a mechanical switch) that was designed for 12V to work fine with 16V. Could you post the exact wording about the switch you found being 12V?
    – Armand
    Sep 11, 2022 at 17:54
  • "16V should be plenty for a traditional chime, although likely too low for a modern smart doorbell." Uh, nope, the "smart doorbell transformer" is same voltage, more VA (thus, more A, same V.)
    – Ecnerwal
    Sep 11, 2022 at 18:25
  • @Ecnerwal I have smart doorbells that say 16V may be too low and recommend 24V instead as part of an insufficient power troubleshooting process. Agree that more amps are needed as well. Just trying to recommend something that will work on the first go. I've edited my answer taking your suggestion though.
    – Armand
    Sep 11, 2022 at 18:38
  • @Armand This is the doorbell I plan on installing: amazon.com/gp/product/B07GX3R43H/… It clearly states only 12V but I figure it will work with 16v. Just curious why they all seem to mismatch. And the ones at the store I think said 12V as well but the trans was 16 (plus the one online was 10).
    – John
    Sep 13, 2022 at 10:02

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