AprilAire 51 Furnace Current Sensing Relay

The AprilAire 51 is the correct replacement for the following humidifiers:

• AprilAire Humidifiers
• Honeywell HE220 Humidifier
• Honeywell HE225 Humidifier
• Honeywell HE260 Humidifier
• Honeywell HE265 Humidifier
• Honeywell HE360 Humidifier
• Honeywell HE365 Humidifier

The AprilAire 51 Furnace Current Sensing Relay is specifically designed for 120 volt applications to interface electronic air cleaners with most heating and cooling systems. Also known as part number 51, this current sensing relay senses a current when the blower fan of your furnace turns on. The AprilAire Current Sensing Relay allows power to slide through the system and turn the humidifier on. This relay can be attached to a wire carrying the sensing current without cutting the wire or breaking the circuit. Once you run the fan wire through the top loop of the relay, the fan will turn on as the relay closes. This sensing relay can be used to simplify the installation of inline duct booster fans.

AprilAire 51 Current Sensing Relay Specifications:

• Part 51
• For 120 volt applications
• Relay closes when fan turns on
• Dimensions: 1" x 1 3/8" x 2 3/4"
• Voltage range: 100-125 VAC, 50-60 HZ
• Current sensing relay for furnace blower fan
• Operating ambient temperature range: 40-104 degrees Fahrenheit

The sensed current of this AprilAire Relay must be a minimum of 4.0 amps. The load in the switched circuit should be between 3 and 50 watts. The AprilAire brand is also known by the following spelling variations: April Air, April Aire and AprilAir. Be sure to disconnect the power before installing or servicing your electronic air cleaner. Do not connect your current sensing relay without load in the series. The AprilAire 120 volt Current Sensing Relay will quickly, easily and inexpensively interface electronic air cleaners with all types of forced warm air furnaces and air conditioning equipment.