GerryB
Senior Member
- Location
- woodbridge, ct. USA
Is there much voltage drop thru a lighted button? I had 25volts at the transformer (dual tap 16v and 24v), 25 at the chime with the wires twisted together, only 19 with the button held in. Normal?
voltage drop thru doorbell button
- Thread starter GerryB
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Not sure about what is normal but 16v is what most chimes are rated so not sure why you are using 24. What is the distance of the run and what gauge wire are you using
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
The light is in the circuit in parallel with the button, so it should not play any role at all in the VD of the button. It will mean that there will be a small current at the chime at all times because of the parallel path through the bulb, though. The chime impedance is low enough that this current will not activate it.
To get a VD of 6V across the closed button, I would say that either you have a defective button or you have a very high current chime and a button meant only for a lower current chime.
The button will be getting very hot if you hold it in, although I believe that many chimes will overheat with the button held in too.
Does the transformer have a thermal cutout?
To get a VD of 6V across the closed button, I would say that either you have a defective button or you have a very high current chime and a button meant only for a lower current chime.
The button will be getting very hot if you hold it in, although I believe that many chimes will overheat with the button held in too.
Does the transformer have a thermal cutout?
GerryB
Senior Member
- Location
- woodbridge, ct. USA
Nothing special here, contractor chime kit, button insert, 25 feet from trans to button, maybe 75' to chime. I didn't think the higher voltage would hurt the chime so I didn't change the transformer. The 19volt reading was with one of the girls holding in the button and the wires landed on the chime, could that account for the reading?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
The lighted button will burn out quicker with the higher voltage
GerryB
Senior Member
- Location
- woodbridge, ct. USA
That's not good. I'll get back there and change the transformer. It's an important doorbell for an inner city business that always has the door locked and relies on the bell.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I may have to retract my statement because if the button lights are led then it may not matter. I do know that the older buttons with the incandescent bulb had issues with the 24v hookup. I mistakenly had it hooked up on 24v and the button was very hot-- the bulb did not last very long. The led's may be able to handle the voltage difference
GerryB
Senior Member
- Location
- woodbridge, ct. USA
Going there anyway to change it. I would have changed it the other day but I found a transformer off the panel that looked like a doorbell transformer, smelled like a doorbell transformer, and actually was a doorbell transformer, just not the right one. Of course I assumed it was. Turns out they had two chimes in the hall and this one wasn't being used. I couldn't find mine at first, then I found it located in the front entrance off a surface mounted octagon box with a combo emerg/exit sign in front of it. (This is a large old house being used as a funeral parlor) So I was out of transformers and people going in and out so I left it. They did say the chime was weak at times so maybe there is a problem with the transformer. I actually couldn't get a reading on the 16volt side of the transformer, just the 24v side so I'm thinking someone may have switched it at some point.
K8MHZ
Senior Member
- Occupation
- Electrician
I seem to remember that some door bell buttons had the light in series and if the light burned out, the door bell would not work.
That would account for a sizable voltage drop if that is the kind of switch being used.
That would account for a sizable voltage drop if that is the kind of switch being used.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
K8MHZ
Senior Member
- Occupation
- Electrician
Years ago I ran into one like that. It was pretty old. IIRC, I couldn't replace it with a regular, unlit switch, I had to order one just like the one that failed.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
If the bulb is in series with the switch contacts, it would only light when you push the button. Normally the light goes out when you push the button. But with a 6V drop across the contacts it might still be dimly lit.
My experiences with bulb not lighting and doorbell not working have all been wiring or transformer problems, not burned out bulbs.
My experiences with bulb not lighting and doorbell not working have all been wiring or transformer problems, not burned out bulbs.
growler
Senior Member
- Location
- Atlanta,GA
I got some door bell push buttons at one time that didn't work right out of the box. When I checked with a meter I found there was some sort of coating on the contacts. I scraped the coating off and they worked just fine.
If you are getting a voltage drop I would think the contacts could be dirty( even new one's ). Just a thought.
They do make door bells that can operate at 24VAC. Need to read installation instructions.
I find that manufacturers are constantly changing things so it's not good to rely on memory.
James L
Senior Member
- Location
- Kansas Cty, Mo, USA
- Occupation
- Electrician
When I started wiring back in the early 90s, our shop always used a 24volt transformer if there were 2 chimes.
Electric-Light
Senior Member
with 100' of wire, that doesn't surprise me.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
You are forgetting that according to the OP the same 100' of wire with the leads twisted together at the button location produced 25V at the chime.
(Unless that was measured with the chime disconnected, maybe?)
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
You do not increase the voltage with 2 chimes but rather you increase the VA. When we have 2 chimes I use a 16v 30va trany and it works fine. I suspect people use the tri tap trany where the 30va tap is 24V.
Something like this
James L
Senior Member
- Location
- Kansas Cty, Mo, USA
- Occupation
- Electrician
You do not increase the voltage with 2 chimes but rather you increase the VA. When we have 2 chimes I use a 16v 30va trany and it works fine. I suspect people use the tri tap trany where the 30va tap is 24V.
Something like this
Higher VA, yes. But I remember when I worked for a shop back in '92-'94. Come to think of it, I believe it was a tri-tap we used
they taught me a whole lot of stuff I had to unlearn later. I was just thinking about the way we did it back then, wondering if 2 chimes would make the voltage drop from 24 to 19 with circuit closed
GerryB
Senior Member
- Location
- woodbridge, ct. USA
The pictured transformer looks like the one I had there. I actually changed it to the one from the contractor kit and the chime was very weak, I had to re-install the 24 volt one. It was quite annoying
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Get a 16V 30va trany and it will work fine. They are about $25-30The pictured transformer looks like the one I had there. I actually changed it to the one from the contractor kit and the chime was very weak, I had to re-install the 24 volt one. It was quite annoying
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