# Intercom Retrofit Questions



## AdamElectric715 (Jan 1, 2015)

First post here! 

So I'm looking at a job in an apartment building that has a pacific 3404 call box installed and the new tenant is deaf so she needs a visual alert system that will flash a light when the doorbell is rung.

Pacific 3404: 
http://www.leedan.com/3404.html

I found the ADA 121:

http://www.housingdevices.com/pdfs/ADA_121_data_and_wire.pdf

Seems like a perfect fit. However, after looking into the product it doesn't seem to have a button to unlock the entry door. I would have to fish a wire and wire parallel off the "pt" and "t" terminals to a push button below (i believe). 

The other problem is I do not know what is available for power, 16 vac that I can use to power the new unit? Or will I have to add an outlet/transformer somehow?

Help please! I feel like i found the right product, just want to make it work.


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## Edrick (Jun 6, 2010)

That accompanies whatever the current door system / door bell is. It's not a replacement. So they would still use whatever they currently use to unlock the door to do so.


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## AdamElectric715 (Jan 1, 2015)

Ahh, I can see that now. Still unsure how to wire it, guess I can do some testing with a meter when I get to the job. Can't find any schematics anywhere that really explain what's what


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## Edrick (Jun 6, 2010)

From what I can tell is it basically looks for one of the following

1) a telephone ring (the device alerts you if the phone rings)
2) a door bell press. So I'm guessing the device connects to the door bell and when the button is pressed it closes the circuit on the screw down terminals for door bell.
3) a button press on a door buzzer like in an apartment. 

So my guess is all that happens is one of those three conditions are met and the device starts buzzing and flashing for a period of time you set.


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## AdamElectric715 (Jan 1, 2015)

Exactly! I'm hoping that there is 16 vac at the existing unit, and two wires that will activate the switch as you are saying (which should be the buzzer situation) and that's all I will need.

If there is only one half of the 16 vac at the unit then I will need to fish an outlet and get a transformer plugged in. 

Thanks for the help!


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