The SOS switch is a solid state device designed to detect a clogged condition in condensate drain lines. It works by sensing when the water is near the top of the pipe that it is clamped onto and responds by opening the circuit to the compressor contactor.
Since there are no moving parts in the switch, slime and sludge buildup do not affect operation until a blockage occurs. The switch is triggered by a near full condition of the drain pipe and is not affected by condensation or water droplets inside of the pipe. Unlike other types of level or safety switches, the SOS does not require cutting or penetration into the pipe and does not interfere with normal fluid flow in any way.

• For use with 24 VAC control circuits
• Pipe must be 80% or more full at the SOS location for a tripped condition to occur.