# New doorbell transforming overheating...



## bobelectric (Mar 3, 2007)

Not to dis you ,but xfmrs always feel hot in service.What is hot to people is normal to transformers.


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## dmxtothemax (Oct 26, 2010)

Yes quite true !
temps of 40 to 50 degrees celsius is normal.
So how hot are we talking ?
If it is just stinking hot,
then there may be shorted turns,
But normally transformers do run quite warm,
almost hot.


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## mvazquez74 (Jun 26, 2011)

bobelectric said:


> Not to dis you ,but xfmrs always feel hot in service.What is hot to people is normal to transformers.


I'm just worried that it may catch on fire. When I did the installation on mine at home. I connected the black and white wires only to the transformer, and left the ground disconnected because there's no ground wire there in the box to connect it to. I replaced everything, button, transformer and chime. And everything is fine, but when I went over to my cousins house to try to replicate this it's not having it. My transformer is cool to the touch and his is extremely hot...


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## mustangmike3789 (Apr 10, 2011)

did you check to see if you have some jahovah witness guys waiting on you to answer the door?:laughing:


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## a7ecorsair (Jun 1, 2010)

Are both transformers variable?
The output voltage reads good, did you check the input side? Just to make sure the connection is correct, measure the input side for 120V.


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## bobelectric (Mar 3, 2007)

You'd know within seconds if the voltage was wrong!


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## a7ecorsair (Jun 1, 2010)

bobelectric said:


> You'd know within seconds if the voltage was wrong!


You and I know this but to lay out a troubleshooting path, it has to be done. What if.... it is connected to an unbalanced MWBC?


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## mvazquez74 (Jun 26, 2011)

a7ecorsair said:


> Are both transformers variable?
> The output voltage reads good, did you check the input side? Just to make sure the connection is correct, measure the input side for 120V.


I checked the input before I installed the transformer, and it read 120v. I noticed the wires that connect to the transformer are located on the other side of the main breaker box is that ok????


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## AllanJ (Nov 24, 2007)

One of the doorbell buttons may be stuck. Doorbell transofmers should not be running current except for the brief moments that someone is pushing a button.


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## a7ecorsair (Jun 1, 2010)

mvazquez74 said:


> I checked the input before I installed the transformer, and it read 120v. I noticed the wires that connect to the transformer are located on the other side of the main breaker box is that ok????


I don't know exactly what you mean by *other side of breaker box*.
It is entirely possible the transformer is defect. When you say the button and chime are disconnected, do you mean there are no wires connected to the low voltage side of the transformer?


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## mpoulton (Jul 23, 2009)

Before you go chasing a phantom problem, confirm that you actually have a problem. As many have already said, transformers get hot. Even with no load connected at all, it may get almost too hot to touch. How do you know it's hotter than it's supposed to be?


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## mvazquez74 (Jun 26, 2011)

mpoulton said:


> Before you go chasing a phantom problem, confirm that you actually have a problem. As many have already said, transformers get hot. Even with no load connected at all, it may get almost too hot to touch. How do you know it's hotter than it's supposed to be?


Yeah nothing is connected to the low voltage side. The only thing connected is the transformer!!!


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## mpoulton (Jul 23, 2009)

mvazquez74 said:


> Yeah nothing is connected to the low voltage side. The only thing connected is the transformer!!!


Transformers still use some current with no load connected (it's called the "magnetizing current"), and thus get hot. The more compact and cheap the transformer, the greater the heating from magnetizing current.


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## AllanJ (Nov 24, 2007)

I am led to believe that a transformer that gets too hot to touch is so cheap that it will not last very long and has a good chance of becoming a fire hazard.


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## a7ecorsair (Jun 1, 2010)

The OP made the comment that he installed two of these transformers, one at his house and one at a friends. Only one seems to have this issue. There is primary current flow all the time and secondary current only flows when a button is pressed. Since heat buildup would be the result of current flow, the only way to troubleshoot this would be with a AC current meter connected (clamped) on the primary side. Without this we are all guessing....


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## dmxtothemax (Oct 26, 2010)

Take both transformers yours and your cousins out,
put them on a table with no load on there secoundarys
and monitor there temps,
you will soon see if there is a problem,
a faulty transformer will soon be too hot.


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