Dual pressure switch
WARNING: This page is about a different car, the 2004 Land Rover Discovery, 2003 Land Rover Discovery, and 2002 Land Rover Discovery. However, it is still accessible from the selected car via links, so may be relevant.
The dual pressure switch protects the refrigerant system from extremes of pressure. The normally closed switch is installed in the top of the receiver drier. If minimum or maximum pressure limits are exceeded the switch contacts open, causing the compressor clutch to be disengaged. The minimum pressure limit protects the compressor, by preventing operation of the system unless there is a minimum refrigerant pressure (and thus refrigerant and lubricating oil) in the system. The maximum pressure limit keeps the refrigerant system within a safe operating pressure.
Dual pressure switch nominal operating pressures
| Limit | Opening pressure, bar (lbf.in2 ) | Closing pressure, bar (lbf.in2 ) |
|---|---|---|
| Minimum | 2.0 (29.0), pressure decreasing | 2.3 (33.4), pressure increasing |
| Maximum | 32 (464), pressure increasing | 26 (377), pressure decreasing |