How to wire a 4251?

Just got my 4251-20 today. I saw 4 terminals but how do I wire it to a 2 wire fire alarm

<URL url="How to wire a pull station to a horn/strobe text=“viewtopic.php?f=60&t=6312#p56918”>How to wire a pull station to a horn/strobe

[quote=“electronicwiz101”]
<URL url="How to wire a pull station to a horn/strobe text=“viewtopic.php?f=60&t=6312#p56918”>How to wire a pull station to a horn/strobe]

I don’t know which terminals are + and -

[quote=“Niklaus”]


For what device?

[quote=“Niklaus”]

On the pull station, the polarity doesn’t matter, meaning there is no + or -. The switch in the pull just creates a connection between the two terminals, numbers 1 and 2 on the rear terminal strip, when it is activated.

Going to beat Lambda to the punch by saying to check the voltage for ALL devices. Even though the 4251 is listed for 120VAC, it doesn’t hurt to be careful.