# 24 volt switch to switch 120 volt light



## josephdanz

I am about to start a project on an air handler that requires a 120 volt UV light inside the air handler for the purpose of killing bacteria. Since the UV rays are very dangerous to people I would like to install a magnet interlock switch on the door of the air handling unit. It seems that pretty much all magnet switches require 24 volt. Is there a rib relay that would sense an open 24 volt circuit and switch open a 120 volt circuit? Or am I going at this the entirely wrong way?


----------



## Peewee0413

Just use a magnetic switch that opens a relay, use 120v for everything. Automation direct has many to choose from. Probably for under $100, and can handle the voltage. 

Sent from my SM-G965U using Tapatalk


----------



## JoeSparky

https://www.functionaldevices.com/products/lighting-controls/light-controllers/

Rib makes a handful of relays that have a control transformer built into them. They are marketed as closet light relays, but they should work perfect in your application


----------



## splatz

The RIBs @JoeSparky posted looks like it would work, I think you'd want the -NC option - the lights are on when the switch is closed. 



If you can find a strictly mechanical latch switch / interlock that works, I might go that way, because simpler is better to me. You don't have to worry about the relay failing or the reed switch sticking or etc.


----------



## Southeast Power

josephdanz said:


> I am about to start a project on an air handler that requires a 120 volt UV light inside the air handler for the purpose of killing bacteria. Since the UV rays are very dangerous to people I would like to install a magnet interlock switch on the door of the air handling unit. It seems that pretty much all magnet switches require 24 volt. Is there a rib relay that would sense an open 24 volt circuit and switch open a 120 volt circuit? Or am I going at this the entirely wrong way?


Get a 24 volt AC lamp. Connect it o the load side of the control transformer.
If someone needs to service the unit, they are going to have to turn it off anyway.
If they know enough to run it with the cover open, they are going to know all about UV lights.


----------

