PSW-690

Supported Applications

The Omega PSW-690 series consists of high purity, all stainless steel pressure and vacuum switches designed for applications requiring a measurement range from vacuum to 500 psi. These OEM mechanical switches feature an external pressure scale and pointer for set point adjustment via a lock ring.

Operating Conditions & Performance

The series covers gage pressure ranges starting at 0.8 psig up to 485.0 psig, with specific models available for vacuum applications ranging from 1.6 to 27.0 inHg and 2.7 to 28.2 inHg. Setpoint repeatability varies by model range, listed as ±0.6 to ±10.0 psig depending on the selected pressure span.

Process temperature limits are specified from -54 to 107°C (-65 to 225°F). The documentation notes that a setpoint change of up to 2% of sensor capacity may be anticipated when the switch is used either below -23°C or above 51°C. Mechanical cycling should not exceed 20 cycles/min, with a rated life of 1 million cycles.

Proof pressure is defined as 150% max pressure for each model range. The enclosure rating is NEMA 4.

Gage Pressure Ranges (psig)

• PSW-691: Decreasing 0.8 to 28.5; Increasing 1.6 to 30.0
• PSW-692: Decreasing 2.0 to 48.0; Increasing 3.0 to 50.0
• PSW-693: Decreasing 3.0 to 96.5; Increasing 4.5 to 100.0
• PSW-694: Decreasing 7.5 to 242.5; Increasing 9.7 to 250
• PSW-695: Decreasing 15.0 to 485.0; Increasing 20.0 to 500.0

Vacuum Ranges (inHg)

• PSW-696: Decreasing 1.6 to 27.0; Increasing 2.7 to 28.2

Configuration Options

The PSW-690 series is configurable across process connections, switch ratings, and fitting types while maintaining high purity wetted materials.

Process Connections & Fittings

• NPT: ⅛-27 MNPT Male fittings (Models with "N" suffix)
• VCR: ¼ VCR Male fittings (Models with "V" suffix)

Switch Ratings & Electrical Options

• Current Rating: Available with 1 A or 5 A switch options, specified by the final digit in the model number (-1 for 1 A, -5 for 5 A).
• Electrical Connection: Standard configuration includes 300 mm (12") pigtail leads using 20 AWG polyvinyl insulated wire.

Housing & Materials

• Wetted Parts: 17-7 pH electron beam welded sensing element and 303 SS fitting.
• Enclosure Construction: 303 Stainless Steel body, zinc alloy with chromate finish locking ring and switch housing, valox cap.

Key Product Differences

The series distinguishes between gage pressure models (PSW-691 through PSW-695) and vacuum models (PSW-696). Model numbers follow the format PSW-69X-FITTING-SWITCH_TYPE, where X denotes the range, FITTING is N for ⅛-27 MNPT or V for ¼ VCR, and SWITCH_TYPE indicates the amperage rating.

Physical dimensions vary by fitting type: units with an NPT fitting measure 51 L x 29 mm Dia (2 x 1.125"), while those with a VCR fitting measure 60 L x 29 mm Dia (2.375 x 1.125"). Weight is approximately 85g (3 oz).

Wiring color codes differ based on the application mode:

• Pressure Switch: Black = Common, Red = N/C, White = N/O
• Vacuum Switch: Black = Common, Red = N/O, White = N/C (reversed from pressure configuration)