Johnson Controls A28PJ-1 Agricultural Thermostat

Agricultural Thermostat, Two Stage, 120/208/240/277 Vac, Two SPDT Switches, 30/110 Degree Setpoint Temperature Range, 2 Degree Differential Each Stage, 2/7 Degree Adjustable Differential Between Stages, 1 3/8" x 2 1/4" Coiled Sensing Bulb, Knob Range Adjuster, Nema 4X

A28PJ-1 is identical to A28PJ-1C

Johnson Controls A28PJ-1 Agricultural Thermostat – Two-Stage, Remote Bulb, SPDT, NEMA 4X

The Johnson Controls A28PJ-1 Agricultural Thermostat is a rugged, high-performance two-stage temperature control designed for agricultural, industrial, and environmental applications. Engineered with a liquid-filled sensing element and capillary, this thermostat provides precise and reliable temperature regulation without requiring an external power source.

Built for demanding environments, the A28PJ-1 features a durable NEMA 4X enclosure, making it ideal for areas exposed to moisture, dust, and corrosive conditions. With two SPDT switches, adjustable differentials, and a wide setpoint range, it delivers dependable performance for heating or cooling control systems.

Key Features

• Two-Stage Temperature Control for versatile heating or cooling applications

• Voltage Compatibility: 120/208/240/277 VAC

• Switch Type: Two SPDT outputs

• Setpoint Range: 30°F to 110°F

• Differential: 2°F each stage; 2–7°F adjustable differential between stages

• Sensing Element: 1 3/8" x 2 1/4" coiled remote bulb for accurate temperature monitoring

• Control Adjustments: Front-control knob for easy setpoint adjustment

• Enclosure Rating: NEMA 4X for harsh/agricultural environments

• No Power Required for Operation

• Fan Switching: No

• System Switching: No

Series Description

The Johnson Controls A28 Series is a two-stage heating or cooling temperature control line that uses a durable liquid-filled sensing element and capillary. Designed to switch line voltages, it includes an exposed or concealed setpoint dial and an adjustable differential for precise environmental control. The A28 Series builds on the reliability of the A19 Series by offering dual-stage functionality and enhanced performance for more complex systems.

Ideal Applications

• Agriculture and livestock buildings

• Greenhouses and nurseries

• Barns, dairies, and poultry houses

• Industrial equipment control

• Environmental chambers

The Johnson Controls A28PJ-1 is a trusted OEM-quality thermostat that offers exceptional precision, durability, and control for demanding agricultural environments. Perfect for both new installations and replacement needs.