Aprilaire Automatic Digital Modulating Control Package for Model 866

Control the relative humidity in your home with precision and ease with the Aprilaire 5558 Automatic Digital Modulating Control Package for the 866 Ductless Steam Humidifier. This wall-mounted humidistat boasts a microcomputer design and offers a large LED digital display with a backlight and the ability to lock in your preferred relative humidity set-point from 0 – 100% RH.

This control also includes an Outdoor Temperature Sensor which automatically readjusts the humidity set-point based on the difference between the room temperature and the outside temperature to prevent window condensation in colder climates.

Additional Wall-Mounted Control Features:

• Selectable Celsius or Fahrenheit scale.
• Outputs controlling humidification and dehumidification equipment by means of on/off or proportional output signals for greater flexibility.
• Modulating Output Signal provides a 0-10Vdc or 2-10Vdc proportional control signal to the humidifier.
• Integrated sensor for better application flexibility.
• Programmable Proportaional Band to increase or decrease the sensitivity of the humidifier control.
• Humidity set-point reset function based on outdoor temperature which helps prevent condensation in colder climates.
• Humidifier On-Off signal 24Vac dry contact capable of handling up to 1 amp.
• Proportional High Limit Override to prevent over-humidification within the duct and costly water damage.
• Multi-level lockable access menu and lockable set point to prevent accidental changes.
• Indicator when outdoor temperature setback is used for winter compensation.