PSW-200

Supported Applications

The Omega PSW-200 Series consists of industrial hermetic pressure switches designed for harsh environments. These units are engineered to monitor vacuum and positive pressure conditions, with a documented measurement range extending from Vacuum to 1700 psi (including specific low-pressure ranges such as 30 inHg vac to 0). The series features rugged construction suitable for demanding process applications where reliable switching is required.

Operating Conditions & Performance

The PSW-200 Series operates within an ambient temperature range of -40 to 71°C (-40 to 160°F), with specific exceptions: models PSW-234 through PSW-240 and PSW-221 through PSW-226 operate from -18 to 71°C (0 to 160°F). Storage temperature is rated at -54 to 71°C (-65 to 160°F).

Process temperature limits vary by wetted material:

• Buna-N: -23 to 93°C (-10 to 200°F)
• Phosphor Bronze: -40 to 149°C (-40 to 300°F)
• Stainless Steel: -57 to 204°C (-70 to 400°F)

The enclosure complies with NEMA 4X (IP66) ratings. Setpoint repeatability is specified as 1% of the adjustable range, except for models PSW-241 through PSW-245D, which are rated at 1.5%. The setpoint typically shifts less than 1% of range for a 28°C (50°F) ambient temperature change.

Mechanical robustness is defined by the following ratings:

• Shock: Setpoint repeats after 15 g, 10 ms duration
• Vibration: Setpoint repeats after 2.5 g, 5 to 500 Hz

Configuration Options

The series offers a broad envelope of configurations across multiple model families (PSW-2xx), covering pressure ranges from low differential pressures in inches of water column up to high-pressure applications. Key configurable dimensions include:

• Switch Output: Hermetically sealed SPDT or DPDT switches, rated at 11 A, 125/250 Vac resistive.
• Housing & Enclosure: Die-cast aluminum body with epoxy coating and gasketed construction. Dimensions for psi ranges are 214 max H x 101 W x 60 mm D (8.4 max x 4 x 2.3"); inH2O range models have a width and depth of 152 mm (6").
• Process Connections: Available as ¼ FNPT or ½ FNPT, depending on the specific model noted in selection charts.
• Wetted Materials: Options include Stainless Steel, Phosphor Bronze, and Buna-N diaphragms with O-rings.
• Electrical Connections: Provided via ¼ NPT conduit entry or (2) 22 mm (7/8") diameter knockouts.

The series includes models with fixed deadbands that tend to increase linearly with increased setpoint. Deadband values are non-adjustable and vary by model range, such as the PSW-234 which lists a 1 to 4 psi deadband for its standard adjustable range.

Key Product Differences

The PSW-200 Series is differentiated primarily by pressure range, switch type (SPDT vs. DPDT), and wetted material construction.

• Switch Configuration: Models ending in "D" feature a DPDT switch with added features for simultaneous contact transfer on rising setpoints; non-D models utilize an SPDT switch.
• Pressure Ranges & Materials: The series is segmented into distinct tables based on diaphragm material and connection size. For example, the Buna-N diaphragm group includes ¼ FNPT connections with stainless steel pressure ports for higher ranges (e.g., PSW-234 to PSW-240) and vacuum/low-pressure models (PSW-246D). A separate configuration offers a ½ FNPT aluminum pressure connection for low differential pressures in inches of water column (models PSW-221 through PSW-226).
• Deadband Characteristics: Deadbands are fixed and non-adjustable. Specific models list deadband as a percentage range or typical value; for instance, the PSW-234D lists a 3.8 psi typ. deadband.