W42AA-1C Johnson Controls Humidity Control

Overview

The Johnson Controls W42AA-1C is a room humidistat designed to provide single-pole, double-throw (SPDT) control for use on low or line voltage applications. It controls humidifying or dehumidifying equipment, or both, to manage commercial and residential HVAC indoor space humidity. The device utilizes a highly stable and accurate human hair sensing element consisting of approximately 150 strands of processed hair, which is mounted vertically to minimize surface contamination by dust.

Features

• Three-wire SPDT switch permits control of humidifying and dehumidifying equipment with one control.
• Stable, accurate, and sensitive human hair sensing element.
• An exclusive tension release device protects hair strands from extreme humidity or mechanical strain.
• Easy-to-read dial with a concealed dial lock screw for sealed settings.
• Separable mounting plate with attached mounting screws to minimize installation time.
• Attractive contemporary styling with a molded thermosetting plastic base and metal cover finished in ivory enamel.

Specifications

• Brand: Johnson Controls
• Model: W42AA-1C
• Voltage: 120 to 240 VAC
• Electrical Rating: 125 VA (Pilot Duty Only)
• Humidity Range: 10% to 90% RH
• Humidity Differential: Fixed at approximately 4% RH (non-adjustable)
• Maximum Operating Ambient Temperature: 100°F (38°C)
• Switch Action: SPDT, 3-wire snap-acting contacts
• Mounting Style: Wall mount (mounts on standard vertical outlet box or flat surfaces)

Applications

• Operating exhaust fans in electrically heated homes to automatically reduce relative humidity.
• Humidity control in environments requiring high accuracy and reliability, such as fruit storage rooms and curing rooms.
• Environmental air management in commercial office buildings, hospitals, schools, laboratories, museums, data centers, clean rooms, and ESD (anti-static) control spaces.