Overrun Request

If an overrun of the fan is required after "Ignition OFF", approximately 7 seconds after "Ignition off", the MSS60 emits a PWM signal with a frequency of 10 Hz for at least 3 seconds. At the issued cycle ratio, the electrical fan system detects at which speed and for what duration the overrun should occur.

The cycle ratio is between 15 and 85% in 5% increments.

It contains the information displayed in the following graphic:

• Engine speeds of 35, 45 or 50% of the rated speed.
• Run-on time of 3-11 minutes in increments of 2 minutes.
  Fig 1: Cycle Ratio Graph

  Courtesy of BMW OF NORTH AMERICA, INC.
  INDEX EXPLANATION REFERENCE CHART
  
  

  Index	Explanation
  A	Percentage of rated speed
  B	Overrun in minutes
  1	Cycle ratio in percent