PSW-180

Supported Applications

The Omega PSW-180 Series is an industrial differential pressure switch or alarm designed to monitor the difference in pressure between two sources. Utilizing dual diaphragm sensors, these units provide reliable monitoring and control for applications requiring a compact footprint with environmental protection.

Key application constraints include:

• Differential pressure measurement where vacuum is not applied to the low side (the piston is not attached to the diaphragm).
• Air temperature up to 70°C (158°F) and media temperatures up to 95°C (203°F) @ 100 psi.
• Environments requiring NEMA 4 (IP65) protection against dust, water ingress, and corrosion.

Operating Conditions & Performance

The PSW-180 series operates within an ambient temperature range of 0 to 70°C (32 to 158°F), with a storage capability from -30 to 80°C (-22 to 176°F). The working pressure rating is 0 to 150 psid at up to 70°C (158°F) air temperature, matching the differential proof pressure of 150 psid.

• Repeatability: 1% of span
• Vibration Rating: MIL STD 810C, 2.5 g, 5 to 500 cps
• Shock Rating: 15 g, 10 ms duration
• Burst Pressure: 150 psid

The series offers adjustable ranges depending on the specific model configuration. For example, models PSW-181 and PSW-183 cover an "On Fall" range of 1.0 to 9.0 psid with a typical deadband of 0.75 psid. Models PSW-182, PSW-184, PSW-186, and PSW-188 support an "On Fall" range of 4.0 to 43.5 psid with a typical deadband of 1.0 psid.

Configuration Options

The series is configurable across process connections, output types, and housing materials to suit specific installation needs.

Process Connections & Wetted Materials

• Polysulfone: ¼ NPSF port (Models PSW-181, PSW-182, PSW-185, PSW-186).
• Brass: ¼ FNPT thread (Models PSW-183, PSW-184, PSW-187, PSW-188).

Housing & Enclosure

The unit features a reinforced polyester body with a zinc-plated steel cover and neoprene gasket. Dimensions vary by material:

• Polysulfone models: 70 W x 60 D x 89 mm H (2.75 x 2.38 x 3.5")
• Brass models: 80 W x 60 D x 89 mm H (3.13 x 2.38 x 3.5")

Outputs & Power

• Switch Output: SPDT rated at 5 A at 250/125 Vac, 5 A at 30 Vdc with gold-clad contacts.
• Audible Alarm: Internal 9 Vdc battery powered (battery included), continuous tone 85 dB. Available on specific models such as PSW-186 and PSW-188.

Electrical connection is via a terminal block with wiring accessible from outside the enclosure using a multiturn screw adjustment mechanism.

Key Product Differences

The primary distinction within the series lies in the combination of process port material and output function:

• Switch Models (e.g., PSW-181, PSW-183): Provide a 5 A SPDT electrical contact for external control circuits.
• Audible Alarm Models (e.g., PSW-186, PSW-188): Replace the switch output with an internal audible alarm powered by a 9 Vdc battery; these models do not provide a SPDT switch contact.
• Port Material: Polysulfone ports (NPSF) are offered for specific chemical compatibility needs, while Brass ports (FNPT) offer robust mechanical threading. The choice of material affects the overall width dimension of the unit by 10 mm (0.38 in).

Note: For models with Polysulfone fittings (PSW-181, PSW-182, PSW-185, PSW-186), Teflon tape must be applied to the fitting for a tight seal, and connection torque must not exceed 2 ft-lbs. Never tighten by turning the control into the fitting.