Series-1831

Supported Applications

The Dwyer Series 1831 is a low differential pressure switch designed for HVAC systems and high duct static cutout applications. The series utilizes air and non-combustible, compatible gases as the service media.

Operating Conditions & Performance

Differential pressure measurement ranges are available in two configurations: 2.5 to 9 in w.c. (Model 1831-1) and 7.5 to 23 in w.c. (Model 1831-2). The series operates within an ambient temperature range of -30 to 180°F (-34 to 82.2°C).

Performance specifications include a repeatability of ±4% max and a maximum actuation delay between contacts of 1 millisecond. Pressure limits are rated for 10 psig (68.95 kPa) continuous service with a surge limit of 25 psig (172.4 kPa). The unit requires no power to operate the DPDT switch mechanism.

Key Specifications

• Measurement Type: Differential Pressure
• Ranges: 2.5 to 9 in w.c.; 7.5 to 23 in w.c.
• Ambient Temperature: -30 to 180°F (-34 to 82.2°C)
• Pressure Limits: 10 psig (68.95 kPa) continuous; 25 psig (172.4 kPa) surge
• Repeatability: ±4% max.
• Actuation Time Difference: 1 millisecond maximum actuation delay between contacts

Configuration Options

The Series 1831 features a DPDT (Double Pole Double Throw) switch configuration, allowing both control contacts to activate simultaneously. The set point is adjustable via a screw-type adjustment located inside the mounting stud.

Housing and connection options include:

• Process Connection: 1/8" female NPT
• Electrical Connections: Screw type terminal block with two conduit entries
• Mounting: Includes an A-389 mounting bracket that can rotate and be tightened at any angle. Mounting orientation requires the diaphragm in a vertical position; consult factory for other orientations.

Key Product Differences

The series is offered with manual reset functionality. Two primary model variations are defined by their differential pressure ranges:

• 1831-1-RA-S: Manual reset DPDT, activate on increase; range 2.5 to 9 in w.c.
• 1831-2-RA-S: Manual reset DPDT, activate on increase; range 7.5 to 23 in w.c.

Static pressure tip accessories are available for specific installation needs, including models A-302F-A (4" insertion), A-302F-B (6" insertion), and A-302F-C (8" insertion) featuring 303 SS construction with mounting flanges. Additional straight static pressure tips include the A-489 (4"), A-491 (6"), and A-493 (8").

Wetted materials must be confirmed by consulting the factory.