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We have a 1915 bungalow that I tore out all of the old knob-and-tube wiring, including the original ginormous doorbell transformer, and installed all new circuits throughout. I purchased a new, decorative doorbell button and am now shopping for a new chime unit.

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I'm installing this doorbell button and chime all new and there is no existing wiring or transformer. What I would like to do is install a wired chime that doesn't use an external transformer. I've performed several online searches but all of the results are mostly for diagnosing faulty transformers as opposed to alternatives for an external transformer.

After doing a lot more research, a "domestic" doorbell chime with an integrated transformer is certainly not common. I came across a single unit: the Nicor Prime Chime, which everyone here on SE was adamant that one like this did not exist aside from European models. This is intended for new construction and uses a dual-voltage box, line-voltage and an integrated transformer. This is kind of what I had in mind, but it's just cramming the typical doorbell components into a single box.

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Unfortunately, reviews of this item are not pleasant, claiming poor audio quality and just poor quality altogether.

Since I have a fancy new wired button, I have no desire to use a wireless or battery-operated doorbell. Is there an alternative method to provide power to a wired doorbell without using the typical external transformer?

NOTE: If you happened along this post looking for an answer to the question, don't bother reading any of the answers posted below. My [original] question seemed to upset a lot of people. If a sufficient answer is ever provided for this question, I will mark it and also note it here in the OP so no one else needs to read all of the useless banter.

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    You said that you know they used to use an external transformer, but what has changed between then and now? Years ago they could have built the transformer into the doorbell unit, but did not. Even today there's little incentive for doorbell manufacturers to build a low voltage power supply into the doorbell unit - doing so would just make it more expensive to get certification. – Johnny Jul 18 '16 at 22:03
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    Voting to close - after reading all the comments on all the answers, this looks more and more like a shopping question asking for product recommendations. – RedGrittyBrick Jul 19 '16 at 14:32
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    @RedGrittyBrick - I appreciate your moderation. Although I am fully aware of "shopping questions" there are two things: the OP is not a "shopping question" as it is asking if a particular type of item is manufactured and there is actually no "rule" about "shopping questions" listed on the SE "Home Improvement" tour page. Also, I can't control the comments other members are leaving and if those elude to "shopping". – paulmz Jul 19 '16 at 14:37
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    @paulmz It's not clear to me exactly what you're looking for. Would the ideal answer be a link to a product you can purchase? If so, those types of questions are off topic here. If you're trying to figure out why a device that fits your specifications does not exist, then anybody outside of a doorbell manufacturer would only be able to speculate. – Tester101 Jul 20 '16 at 17:41
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    My personal decision in voting to close was related to Paulmz's self answer which was links to products that would resolve the problem. If you want help finding a product, it's shopping advice. I also don't see a good solution to avoiding your vampire power concern, you need 24v going to the button at the door or significantly upgraded wiring and a different button. – BMitch Jul 20 '16 at 18:01
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The answer is NO. All wired doorbells must be low voltage by NEC. You can find chimes with the transformer in the chime box, or mounted in a jbox behind the chime box, and you run 120 vac to the transformer, but all the actual chime and buttons must be wired from the low voltage side of the transformer. It's a simple series circuit.

  • "You can find chimes with the transformer in the chime box" I haven't found an example of one yet. Do you have links to show a chime with an internal transformer that still has a wired button option? – Adam Davis Jul 19 '16 at 16:42
  • Shirlock found a European version which obviously requires 240V. Fortunately 240V is one of the two voltages readily available in American installations, so that fully satisfies OP's answer. Alternately one of those Euro products may have a 120V tap on the primary of its transformer. Either way, you must now bring 120/240V to the chime location in a *proper manner, whereas before, you could use the more relaxed thermostat-wire rules. – Harper - Reinstate Monica Jul 19 '16 at 21:33
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In the UK, the vast majority of doorbells are battery-powered. On my old-school mechanical doorbell, two alkaline D-cells are lasting me around 3 years.

As for why there's an external transformer, that's simple. It's not "antiquated", it's actually a modern phenomenon. All mains-connected equipment needs safety testing (CE, TUV, or whatever your local version is). If the mains connection goes into your equipment, you need to pay for that safety testing. Even then, if anything goes wrong then the person who signs off on the design is personally liable for all consequences, up to and including jail time.

If there's an external transformer, the transformer manufacturer has to have paid for that safety testing. You can then buy the transformers off the shelf, and build your doorbell secure in the knowledge that you don't need to worry about mains safety regulations, jail time, or getting sued. If the worst does happen, the transformer manufacturer is liable.

  • Again- sorry- this does not answer the question. I know why doorbells need a transformer. I just want one that is integrated. There is no reason- except for "backwards compatibility"- that doorbells require an external transformer. – paulmz Jul 19 '16 at 14:21
  • I know the difference between "anecdote" and "data", but I've never come across a battery-powered doorbell in the UK. Certainly, houses built 40 years ago were being fitted with transformer-powered bells But I did once live in a house in the UK with a clockwork powered bell, mounted directly on the inside of the door behind the bell push! The domed cover was both the bell itself, and the spring winding mechanism - a neat piece of design. – alephzero Jul 19 '16 at 15:02
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    @paulmz I've just given you a very good reason, which is mains safety regs. Your doorbell manufacturer can pay tens of thousands of dollars per regulatory authority and be liable in case something goes wrong; or they can buy something off the shelf which means they don't need to worry about any of that. Sure, there's no technical reason - but there is a VERY strong financial and legal-liability reason. It's not about backwards-compatibility, it's about common sense as a company. – Graham Jul 19 '16 at 16:54
  • I don't see the advantage of an "integrated" transformer. It won't save power, it just moves the transformer from one place to another. If your complaint is that you don't want a hard-wired transformer, fine, use one that plugs in -- but you seem to be describing a difference that makes absolutely no difference. – keshlam Jul 22 '16 at 13:26
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This is where the low voltage and high voltage sections of the UL code interact in an odd and problematic (for you) way.

The wire from the chime to the button is low voltage. You also want the chime itself to be powered directly from high voltage. The two voltages cannot be placed in one junction box.

So your desired doorbell chime unit must support attachment to two separate junction boxes, or a specialized junction box with a divider UL approved for both low voltage and high voltage on opposite sides of the divider.

This then means that the doorbell chime unit is specialized, and not as modular as the existing designs.

I understand the logic behind your request, but no one makes such a unit because it would be so very niche, and wouldn't fit into existing construction without a high cost, and no builder would choose it because their customers would later complain about repair and replacement.

If you buy a very large doorbell chime, and choose a very small 120/240vac to 16-24vac converter, you could mount it inside the chime and create the product you want very easily and inexpensively. This may be the only way to obtain the exact design you want. To comply with code you'll have to figure out a way to mount the chime onto junction boxes so you can pass an inspection, and here I'd suggest you talk to your inspector before you embark to make sure you don't end up doing a lot of work only to have it rejected by the inspector. I doubt you want to fight city hall over a door chime, but I suppose many people have spent more money on issues with less value, so maybe this really is that important to you, but keep in mind that your modified product won't be UL listed, so you'll have to convince them it's safe, and that's not a small hurdle.

What some people do, though, is mount the transformer into a junction box near the chime (sometimes behind it) with a full plate on it and only the low voltage wires showing on two exposed terminals*, then the button wires entering the wall through another hole separate from the transformer junction box. Yes, it's explicitly not what you want, but by placing the 120V line in a box at the chime then you can use the existing designs until you find the design that does everything you want. A temporary fix that's easy to convert into the desired final solution later might be your best choice for now.

*Again, you can't just squeeze the transformer with low voltage and high voltage wires into the box, then you'd have low and high voltage wires in the same box without a proper divider. This is why doorbell transformers are so specialized, they're meant for permanent installation, and thus must meet UL requirements for installed wiring, they can't simply be power bricks with a plug on one side and a coaxial jack on the other like a small device power supply. It's irritating, I understand, but you do want wiring from the chime to the button, and I doubt you want to deal with a high voltage button, so the wiring must be low voltage, and thus you have to deal with the difference between the two systems and their requirements.

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    Except that most appliances have a cord, are not permanently installed, and don't also have a low voltage permanent installation wire. It's not at all the same within the UL code. The answer to your question, "Is there such a thing as a wired doorbell chime (U.S. voltage) that is direct-wire and doesn't require an external transformer?" is no. Unfortunately you can't (easily) prove a negative, so I'm not putting it in the answer, instead I've given you the code reasons that make the device you seek very, very unlikely to exist. You can then draw from that what meaning you like. – Adam Davis Jul 19 '16 at 16:37
  • Correct- most appliances do have a cord and others have "external" transformers as DC adapter plugs. But let's consider low-voltage lighting, like exterior landscape lighting. This type of lighting has a simple box, either hard-wired or plug-in with line voltage, and an internal transformer converting the power for the lights. As for code reasons, I don't understand how code allows an open transformer with exposed line- and low-voltage connections to be screwed to the basement ceiling. It's hard to argue code, though, since a fair amount of code is still antiquated. – paulmz Jul 19 '16 at 16:50
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    @paulmz "I don't understand how code allows an open transformer with exposed line" It no longer allows this. Low voltage, yes, but line bust be contained within a suitable junction box. Some transformers mount directly to the junction box, while others include a code approved box where the wire can enter before termination. All high voltage lines must follow this code, but certainly there are dodgy installations, some of which used to be code compliant. – Adam Davis Jul 19 '16 at 17:06
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What you are suggesting would require running 120V mains voltage to the doorbell and/or the push-button. Every US house built in the last 100 years has low-voltage wiring for the doorbell which cannot safely carry 120V. Trying to rewire an existing house for a mains-voltage doorbell would be expensive.

Also wiring the doorbell for 120V, you would still probably need a low-voltage wire run to the button. Putting 120V into a small, weather-exposed button would not be safe without making it much more expensive.

Easier all over to just leave the transformer in place.

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    Sorry- I am not suggesting to run 120 volts to the button. What I'm saying is that there isn't any reason why a single doorbell chime unit can't have 120 volts run into the unit that has an internal transformer which would then use the standard low-voltage line for a button. I don't think the OP references wiring the button with 120 volts at all. I'm looking for a modern wired doorbell unit and not how to wire it the wrong way. Thanks anyway. – paulmz Jul 18 '16 at 21:33
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    Also- I have no existing transformer. I'm installing all new from scratch. – paulmz Jul 18 '16 at 21:34
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    I think it's the old chicken-and-the-egg problem. There's no demand or it with existing houses so no one will manufacture it so no builders will try to change the wiring for new houses. – DoxyLover Jul 18 '16 at 21:36
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    Again- sorry- but this still doesn't answer the question. There might be no demand for existing houses, but for new construction there should be a better way to wire a doorbell. Again- thanks anyway. – paulmz Jul 18 '16 at 21:39
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    You know, you're talking to a forum full of code experts. I suspect you are looking at an installation which is not to current code, possibly grandfathered. That doesn't make transformers bad. As far as "there is no logical reason", that is a very common feeling when an EE comes into Code electrical. It will pass. – Harper - Reinstate Monica Jul 19 '16 at 22:31
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A couple of reasons for having an external transformer:

  • The transformer can be kept out of the way at the fusebox or some other obscure place. Then only low-voltage wires are used to where the bell and button a placed.
  • There might not be an outlet where the bell is most effective, like at the top of the wall, and we want to avoid consumers putting the bell on an extension cord or cutting and extending the lead.
  • In an appartment building you can have many bells sharing the same transformer. The producers does not want to make two versions, with and without transformer.
  • The bell-producers can make many different bells, and only a single model of transformer which needs to be approved. The bell-producers does not even have to produce their own transformer.
  • The bell may be used on all continents, regardless of 120V or 240V, just with the right transformer.

I fail to see any argument good enough for producing a bell with internal transformer. If a single model exists, I bet your SO does not like the sound of it ;-)

(Sorry for not putting this as a comment, but it is to wordy, and I need the bullet points...)

  • Although these can be good points, none of them apply to my question. Again- I understand why doorbells use transformers. But there is no reason for them to remain designed external from the chime unit. Most other electrical fixtures (lights, fans, smoke detectors, appliances) are (or can be) direct hard-wired. A doorbell is just as, if not more permanent than these other fixtures. There is no logical reason why a doorbell isn't designed similar to these other wired systems. Thanks anyway. – paulmz Jul 19 '16 at 14:28
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    "There is no logical reason why a doorbell isn't designed similar to these other wired systems." You appearently failed to read my and the other respondents answers, – Lenne Jul 19 '16 at 14:31
  • I thoroughly read and also responded to your and all other comments. It is all of the commenters who did not thoroughly read or understand the OP before posting. No one has answered the actual question. Instead, I only received various histories of the doorbell. – paulmz Jul 19 '16 at 14:41
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    So the answer is NO, nobody in their right mind would produce such an internal powered bell, because there is absolutely no reason which overrules the reason NOT to do have the transformer inside. – Lenne Jul 19 '16 at 16:46
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I suggest using a wireless chime and "rigging" the wireless doorbell. You can hook some low voltage wires to the switch in the wireless transmitter, then use the receiver/chime as usual. The only problem becomes where to hide the transmitter.

You can also find some transmitters that look a lot like your door bell button, and put your button over the top of the transmitters guts.

The same theory should work with a wired unit. Run some low voltage wire to the button and then use a relay to trigger the wired chime. That said I don't know why that would be easier then a kit like http://www.homedepot.com/p/Heath-Zenith-Wired-Door-Chime-DW-57/202595417 that one.

Your old door bell should work just fine with a modern chime. Stashing the transformer somewhere really isn't that big of a deal. You could always hide it in something like http://www.lowes.com/pd/WIEGMANN-144-cu-in-Metal-New-Work-Wall-Electrical-Box/1099361 in a closet somewhere.

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Shirlock Homes has best answer - even though, it's in a comment to this one. They make integral-transformer chimes in Europe. "But I want one that's American voltage" -- 240V is an American voltage.

The idea of a 120V version is a neat idea that might be profitable, and this is where I would strongly nudge OP to put his money where his mouth is, form a company, and find out for himself. Build your better mousetrap.

For those other readers passing by, if you don't want to provision a doorbell transformer, you can steal 24VAC off the transformer in your furnace-A/C system. Most systems have this, certainly any with a thermostat that lets you select A/C vs heat, or fan on/auto. However they will not exist on all-electric convection systems (baseboard), nor all-gas "works with the power off" Empire style furnaces.

If your house doesn't have such a system, they sell 24V transformers which replace a junction box lid, for about $12, which can be installed anywhere in the house or crawlspace, so you are not burdened with a bulky or unaesthetic transformer in living spaces.


As to OP's notion that the idea of 2 power systems in an American home is outdated, I'd argue the opposite. Today, American homes have a constellation of tiny loads: cell phone charger, cable modem and router, NiMH battery charger, LED lighting, scanner, inkjet printer, smart switch, smart thermostat, and yeah... doorbell. These loads actually want to be low-voltage. Having them at 120V makes them more expensive.

The abolition of the wall-wart is, itself, strong argument for a second power system. But here's another emerging factor: Solar. Putting up a solar/battery system is staggeringly easier if it is limited to low-voltage DC loads.

With sane upsizing, modern refrigerators and freezers are efficient to run on it too. This opens the gates to homes transitioning to low-voltage for occupancy-critical loads. The big barrier right now is the unfortunate tendency to build gas/oil furnaces that are utterly dependent on AC power. That could be overcome, and I could see houses in the near future that are outage-resilient, so people "nest" during hurricanes and ice storms with hot cocoa and Netflix rather than flee an uninhabitable home (many Sandy survivors were unhappy to discover their panels don't already work this way). I think it'll happen.

  • Thanks for the suggestion, but I'm not looking to rig something up. I could just as easily install a doorbell transformer. I just don't want to because there should be an updated way to do it by now. Thanks anyway. – paulmz Jul 19 '16 at 14:19
  • External transformers IS the updated way in this globalized world. Many low-power appliances come with "wall-warts", making it easier to just add a power supply for the part of the world you aare shipping to, – Lenne Jul 19 '16 at 14:34
  • @Lenne - External transformers are not the updated way but more one of two ways. So many other electronics and appliances- like TV's, computers, stereos, etc.- that have internal transformers. There are also countless items, including the electronics and appliances I previously mentioned, that are NOT globally designed. Why does a doorbell need to be globally "universal"? – paulmz Jul 19 '16 at 16:39
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    @shirlockhomes Well done, old chap! Power it off a 2-pole breaker... in for a penny, in for a pound, as they say. You should make that an answer; it's a straight answer to an unstraight question. CE listing should pass muster over here thanks to the trade agreements. (and it's probably tougher anyway.) – Harper - Reinstate Monica Jul 19 '16 at 19:26
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    We both have 240VAC systems. They peg ground at the bottom of the secondary so one leg is near 0V from ground and the other 240V. We peg ground at the middle of the secondary, making each leg 120V from ground. This gives us 120V also, which they do not have. – Harper - Reinstate Monica Jul 19 '16 at 20:49
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Battery powered (optional), analog chime, 6 volt doorbell :

http://www.ukelectricalsupplies.com/CED-Mains-or-Battery-Doorbell-Bath.htm#terms

Can be used with 4 x C Battery or 8v Transformer

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Line voltage? no. They're either powered by batteries or a transformer.

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