Premium Digital Humidifier Control Safety and Installation Instructions READ COMPLETE INSTALLATION INSTRUCTIONS AND TEMPLATE BEFORE STARTING INSTALLATION. WARNING ATTENTION INSTALLER: This product must be installed by a qualified heating and air conditioning contractor. Failure to do so could result in serious injury from electrical shock.
WARNING 1. 120 volts may cause serious injury from electrical shock. Disconnect electrical power to the HVAC system before starting installation. 2. Sharp edges may cause serious injury from cuts. Use care when cutting plenum openings and handling ductwork. CAUTION 1. Do not set humidity higher than recommended. Condensation damage may result. 2. Do not set humidity up to recommended levels if there is condensation on the inside of windows of any unheated living space. Condensation damage may result. 3.
STEP 2: Disassemble the Humidifier Control Figure B Use the “OFF” setting to turn the Water Panel Change Indicator OFF. NOTE: When using the Model 50 Current Sensing Relay, the Water Panel Change Indicator MUST be OFF. Remove the knob. Remove the cover by pulling at the bottom and swinging it out and upward. STEP 3: Check the Mode Switch See Figure H (on page 12) for the mode switch (labeled A and B). Make sure the switch is correctly set for the type of humidifier installed.
DUCT (SHEET METAL) MOUNT: STEP 5: Determine Location for Humidifier Control and Mount Control Humidifier Control must be mounted on the Return Duct, at least 6 inches upstream of the following (see Figure C): After location for Control is selected, drill a 3/4 inch hole for the RH sensor (the RH sensor extends from the back of the Humidifier Control).
Figure D – Fiber Board Duct Mount Figure E – Digital Humidifier Control 24V Terminals CONTROL BOARD COVER GASKET SCREW (x2) R KNOB C A B ODT W/G Cf H INSIDE OF RETURN DUCT OUTDOOR TEMPERATURE SENSOR OR MANUAL MODE RESISTOR BASE PLATE SHEET METAL PLATE RETURN DUCT RETURN DUCT CUT OPENING IN RETURN DUCT SHEET METAL PLATE 24V BLOWER OPERATION SIGNAL FROM HVAC EQUIPMENT FOR COMMUNICATION WITH APRILAIRE 8570 THERMOSTAT CONTINUOUS 24V POWER FOR CONTROL 24V SIGNAL TO HUMIDIFIER 90-1203 8 90-
STEP 6: Determine Location for Outdoor Temperature Sensor STEP 8: Alternate Location for Outdoor Temperature Sensor The location of the Outdoor Temperature Sensor must meet these three requirements: The Sensor can also be mounted in the center of either: • PVC fresh air intake pipe for the HVAC system 1. Must be mounted on North, East or West side of house out of direct sunlight 2. Must be at least 3 feet from all exhaust vents 3.
STEP 9: Route the Wire from Control to Sensor Run wire to the outdoor temperature sensor. Sensor is not affected by lead length. Do not run outdoor temperature sensor alongside wires carrying high voltage (120 VAC or higher). Secure the sensor bracket with a #8 screw. STEP 10: Attach Sensor Wire to Humidifier Control Strip wire 1/4 inch, and insert the wires from the Sensor into the terminals labeled “ODT” on the Humidifier Control. See Figure H for location of terminals.
STEP 11: Power Source for Humidifier Control – Terminals R and C Wire external 24 VAC transformer into a constant power source other than the heating, ventilating, air conditioning equipment (HVAC) blower circuit. The transformer can be powered off the 120 VAC line at the junction box before it enters the HVAC. Connect the 24 volt side of the transformer to the “R” and “C” terminals on the Humidifier Control. NOTES: • The Humidifier Control must be continuously powered for proper functionality.
USING FURNACE TERMINALS TO DETECT FURNACE BLOWER OPERATION (FIGURE L) USING HUMIDIFIER CONTROL TO ACTIVATE HVAC BLOWER ON CALL FOR HUMIDITY (FIGURE M) This configuration allows the humidifier to run only during heat call, even if the thermostat is set for continuous fan operation.
HEAT PUMP WIRING (FIGURE N) This configuration allows the humidifier to run whenever the heat pump blower is running (and the Humidifier Control is calling for humidity). The humidifier solenoid should be plumbed to hot water for this option. USING MODEL 50 CURRENT SENSING RELAY TO DETECT FURNACE BLOWER OPERATION (FIGURE P) This option is to be used only if the furnace terminals or accessory terminals are not used. NOTE: The Water Panel Change Indicator must be set to the “OFF” position for this option.
MODEL 8570 THERMOSTAT OPTION (FIGURE Q) SYSTEM CHECKOUT The Model 8570 Thermostat provides the signal that the HVAC is operating. The outdoor temperature sensor can be connected to the Humidifier Control or to the Model 8570. If the Humidifier Control is operating in Manual Mode, the Model 8570 will display a constant outdoor temperature of about 20°F.
TROUBLESHOOTING TROUBLESHOOTING PROCEDURE (CONTINUED) Applies to both Automatic and Manual Operation unless indicated otherwise. SYMPTOM Call Dealer For Service Light Flashing (see Figure R) TROUBLESHOOTING PROCEDURE Display Error Code: E1: RH Sensor Rotate Humidifier Control knob to the “Test/Reset” position. After 5 seconds, the green “Humidifier On” light will blink, resetting the error. If E1 returns, replace the Humidifier Control.
SYMPTOM Humidifier does not operate in “Test/Reset” mode TROUBLESHOOTING PROCEDURE • Make sure that the blower is operating and the HVAC system is calling for heat. • Check wiring diagrams for correct Humidifier Control installation. • If connected to a Model 400 Series humidifier, make sure both floats in the bottom of the scale control insert are in the down position. If necessary, dump out water to lower the floats.
SYMPTOM SYMPTOM Humidifier operates only in “Test/Reset” mode Humidifier operates constantly • If outdoor temperature is greater than 60°F or less than -30°F, the Humidifier Control will only operate in the “Test/Reset” mode (for 1 minute).
SYMPTOM Humidifier or Humidifier Control “chatters” or clicks On and Off rapidly TROUBLESHOOTING PROCEDURE • Check for steady 22 VAC to 30 VAC across the “R” and “C” terminals of the Humidifier Control with a voltmeter. • Check, with a voltmeter, that the HVAC signal across the “W/G” and “Cf” terminals of the Humidifier Control is a steady 22 VAC to 30 VAC. • Make sure that the Outdoor Temperature Sensor wiring is not running alongside other wires carrying high voltage (120 VAC or higher).
