Aci A/RH2-1K-2W-O Outdoor Rh Sensor 4-20ma 1000 Ohm Rtd

Product Description

The ACI A/RH2-1K-2W-O is an outdoor relative humidity sensor designed for building automation and HVAC control applications. It combines a capacitive humidity sensing element with a 1,000 ohm platinum RTD (385 curve) for simultaneous temperature measurement, delivering a default 4-20 mA output signal with selectable 0-5 VDC and 0-10 VDC outputs. Measurement accuracy is rated at 2%. The unit is housed in a poly Euro enclosure rated for outside air mounting, and operates on 24 VAC or 24 VDC power. Licensed controls technicians and building automation specialists are the primary installers of this sensor.

This sensor is suited for outdoor air humidity monitoring in commercial and light-industrial HVAC systems. Typical applications include economizer control, psychrometric calculations, enthalpy determination, and dew point monitoring. Its poly enclosure and outside air mount configuration also make it appropriate for wash-down environments where moisture exposure is a concern. It is wired as a two-wire RTD configuration, simplifying field installation into BAS and DDC controllers that accept standard analog inputs.

Key Features

• 2% relative humidity accuracy for reliable control decisions
• Default 4-20 mA output with selectable 0-5 VDC and 0-10 VDC analog outputs
• 1,000 ohm platinum RTD (385 curve) two-wire temperature element integrated into the assembly
• Operates on 24 VAC or 24 VDC power supply
• Poly Euro enclosure rated for outdoor air and wash-down applications
• Suitable for economizer control, enthalpy, dew point, and psychrometric calculations

Compatibility

Designed for outside air mounting in commercial HVAC building automation systems requiring analog humidity and temperature inputs, including economizer control panels and DDC controllers that accept 4-20 mA, 0-5 VDC, or 0-10 VDC signals alongside a 1,000 ohm RTD input.

Installation Notes

Installation should be performed by a licensed controls technician or qualified HVAC professional. Disconnect and lock out all power to the control panel before wiring the sensor. Mount the enclosure in a location that provides representative outdoor air exposure while shielding the sensor from direct water impingement and direct sunlight where possible. Verify controller input configuration matches the selected output signal type before commissioning.

Technical Specifications

• Accuracy: 2%
• Output Signal: 4-20 mA (default), 0-5 VDC, 0-10 VDC selectable
• Sensor Element: 1,000 ohm platinum RTD, 385 curve, two-wire
• Power Requirements: 24 VAC or 24 VDC
• Mount Type: Outside air (OSA)
• Housing Material: Poly (Euro enclosure)
• Applications: Outdoor air humidity, economizer control, psychrometric calculations, enthalpy, dew point, wash-down environments

Standard Information

• Brand: ACI
• Manufacturer Part Number: A/RH2-1K-2W-O