Auto-idle – PS61 Series Pressure Switch


As emissions regulations continue to get stricter, OEMS are looking for ways to meet or beat the specifications to ensure that their equipment is in compliance.  One of the largest adders to emissions is idling gas/diesel-powered equipment.  As an operator is using a machine, they will increase the idle RPM so that there is plenty of power on the PTO (Power Take Off).  Having this extra power allows the machinery to operate efficiently and without strain.

But, there are times that the operator might be occupied with another task or they might jump off the machine to address another issue.  Having the piece of equipment running at a high idle adds un-needed emissions into the atmosphere.  It also consumes more fuel and increases engine noise levels.

To prevent this from happening, the ECM (Engine Control Module) monitors the pressure in the hydraulic system controlling the PTO.  If there is demand on the PTO (for example, the operator is picking up a tree trunk), pressure in the system will be high and the ECM allows the engine to idle at a high rate.  But if the operator is not using the PTO, pressure in the system will be low, the ECM sees that it is low and the ECM will lower the idle down to a lower level.

This process is called “Auto-Idle” or “Automatic Idle Down”.  A pressure switch is required to monitor the pressure in the PTO system and send a signal to the ECM.


Application Challenge:  

Finding a rugged pressure switch that can provide an accurate signal when used heavily in an aggressive environment and withstand a high number of cycles. 

The switch can see a high number of cycles during use.  The switch will be activated and deactivated every time the PTO is used and when other demands are placed on the PTO/Hydraulic system.  Also, being directly tied into the hydraulic system, high-pressure spikes can be seen by the sensor.  Mounted on outdoor/farm equipment, the pressure switch required will need to be able to handle the shock, vibration, heat, and water spray to survive.  


Application Solution: 

The redesigned PS61 Series Pressure Switch has been designed and tested to survive for over 2,000,000 cycles so that the operator can be assured that their equipment will have a long life.    This is critical in outdoor OHV applications. 

The PS61 Series Pressure Switches also has been extensively tested to withstand up to 7,000 psi (483 bar) of pressure without incurring any type of damage.  Also, MIL-STD 202G testing for vibration and shock has been achieved.   The electrical connection back-ends have been designed and tested to IPX7, IPX9K, and IP6KX so that they are resistant to dust, high-pressure/high-temperature wash-down, as well as submergence


Adding the PS61 Series Pressure Switch to your forestry equipment application is a major asset to ensure your equipment will reduce emissions, consume less fuel and reduce engine noise levels. 

Features of the Gems PS61 Series Pressure Switch: 

  • Exceptional Long-Term Stability = No need for costly field calibration or replacement 
  • Operates over 2,000,000 cycles = long life without need for replacement
  • Sealed to IPX7, IPX9K, and IP6KX = heavy water spray, power-washing, submergence
  • Computer Controlled Calibration = High 1:1 Interchangeability from unit to unit 
  • Passes MIL-STD-202G Vibration, Shock, and Free Fall test = Rugged design to handle excessive shock and vibration conditions 
  • Industry-standard pressure port options = will work in most applications
  • Industry-standard electrical connection options = will work in most applications


Adjacent Products:

  • 3100/3200:  hydraulic oil pressure
  • XT/XM-700:  hydraulic reservoir tank level, links product landing pages
  • LS-7:  fluid reservoir tank low/high level