These pressure switches are designed for use in the hydraulic systems of Lancair 235, 320, 360, Legacy, and IV aircraft, replacing original Lancair part numbers PS550 and PS1100.

Each switch is factory preset by O’Day Design, allowing installation without requiring a pressure gauge. For advanced setups, both units remain fully adjustable to accommodate system-specific tuning.

Available Configurations:

• 700-0105 — Low Pressure (Gear Down)
  Preset: 550 PSI
  Replaces: PS550
• 700-0106 — High Pressure (Gear Up)
  Preset: 1200 PSI
  Replaces: PS1100*

Key Features:

• 1/8″ NPT male fitting
• Viton® internal seals for superior compatibility with hydraulic fluids
• Compatible with both relay and solid state controllers! (4A max)
• 14V and 28V system compatible
• Included 1N4007 flyback diode to reduce electrical arcing and extend switch contact life
• Preset for typical installations, yet field-adjustable as needed

For relay-controlled systems, we recommend installing the included diode across the relay coil (pressure switch terminal and relay housing) as shown in the wiring diagram below. This significantly reduces contact wear caused by inductive kickback.  The diode is not needed if using a solid state controller.

*While the original PS1100 switch was nominally set to 1100 PSI, most Lancair documentation specifies a 1200 PSI system pressure. Accordingly, 700-0106 is preset to 1200 PSI for proper system operation. If required, the switch may be adjusted down to 1100 PSI. This is sometimes needed when the pumps pressure relief valve (PRV) setting causes pump cycling (pressure oscillating above and below the switch threshold). However, in most cases, adjusting the PRV upward is the preferred solution, as it maintains proper system pressure and reduces unnecessary pump cycling. Refer to Page 28 of our Hydraulic Pump Manual for PRV adjustment guidance.

This product is designed to fit the Lancair 235, 320, 360, Legacy & IV models.