Johnson Controls W42AA Low or Line Voltage Humidistat (120/240v, SPDT)

The W42AA humidistat provides single pole, double-throw control for use on low or line voltage applications. The humidistat's terminals are marked for easy wiring. The 'C' terminal is common. The circuit between 'C' and 'L' terminals closes on a decrease in relative humidity. The circuit between 'C' and 'H' terminals closes on an increase in relative humidity. The humidistat?s sensing element consists of approximately 150 strands of carefully selected and processed human hair -- proven to be the most sensitive and stable material known for humidity control. An exclusive tension release device keeps the hair strands from being damaged by extreme humidity or mechanical strain. The sensing element is mounted vertically to minimize surface contamination by dust or foreign material. The humidistat mounts on a standard outlet box or directly to a flat surface where permitted by electrical codes. Features: Three-wire SPDT switch permits control of humidifying or dehumidifying equipment or both with one control St...