Door Chime

[topend]

I have spent too much time troubleshooting this doorbell replacement, and am about to recommend a wireless type. Here's my last ditch effort to avoid that solution.
I am replacing an old Nutone chime that was tied into the intercom system and in addition to the "FRONT", "REAR" and "TRANS" terminals there is a "COM" terminal and conductor. I assumed that the fourth wire was not needed (as the new chime does not have a terminal marked "com(mon?)" The chime does not function. There are also four pair of wires at the transformer.
Any ideas?
Thanks in advance,
Rich

 

[BigDon]

Door Chime

I don't know what model you're replacing it with. Are you sure that they both require the same input voltage and current? If I've thrown away the datasheets, and can't find the manual on-line, I would try wiring it up on my workbench before installing it. I have a variable transformer, and would set it at whatever input voltage is on the label, and would just keep testing the different terminals to see what combination would make it work. If I need to, I also have a selection of AC wall transformers (the kind for electronic devices) that I've cut the output connector from, and just wire it into the device. Some of these have selectable ranges. Hopefully, there is some information on what the input voltage and current are for the chime so that you can select the correct transformer. Good luck.

 

[LawnGuyLandSparky]

I have spent too much time troubleshooting this doorbell replacement, and am about to recommend a wireless type. Here's my last ditch effort to avoid that solution.
I am replacing an old Nutone chime that was tied into the intercom system and in addition to the "FRONT", "REAR" and "TRANS" terminals there is a "COM" terminal and conductor. I assumed that the fourth wire was not needed (as the new chime does not have a terminal marked "com(mon?)" The chime does not function. There are also four pair of wires at the transformer.
Any ideas?
Thanks in advance,
Rich

Older chimes (Westminster chimes) played a 16-note sequence for the front door, an 8 note for the side, and 2 notes for the rear. As such, there is a motorized cam which is activated by the respective buttons which requires the power to be connected to "Comm" and "Trans" and the buttons connected between common and their respective terminals on the chime.

This is because a standard Ding-Dong chime would ding when a button is pressed, and dong when released. This won't work for a Westminster chime, because after the button is released it still has to play another 14 notes. So the front pushbutton is just an actuater to start the motorized cycle.

Unlike a standard 2-note ding-dong doorbell, which only need a switchleg from each door.

The 4 pairs at the chime location are the transformer, the front side and rear doors. 1 pair to each.