Cooling Fan Active and Sevcon Configuration

 Cooling Fan

A cooling fan from Thunderstruck (Full kit) was a quick way to assure the liquid cooling of the ME1616 motor was providing maximum benefit.   A liquid cooled heatsink was also installed under the Sevcon Gen 4 controller to protect it from thermal issues.  

Wiring

A standard 12V relay was installed on pins 7 & 8 on the Sevcon controller to switch the 12V (car 12v) supply for the fan.  The coolant pump was permanently wired to the 12V supply to run continuously while the ignition is on.  The theory is the fan does not need to run unless the motor is getting too warm.   I may install a DC Speed control on the fan to slow it down and reduce its sound level, but I'll have to see if the reduced cooling creates any issues.

Sevcon Configuration

As expected, the Sevcon settings took longer to figure out than the mechanical or electrical work.  Here are the settings to make the fan work.

• Input/Output (tab in Helper) Local Contactor Outputs:  Contactor 2 = Not Mapped, even though there is an option for Traction Motor Cooling Fan.  If this is mapped, Pin 7/8 will be energized whenever the controller is in Operational mode, regardless of the Fan Settings.
• External Heat Sink Fans 0x5A01 or 5A01h:  This is where the temperature set points are entered.  I ended up setting the Fan Temperature Source to Motor Temperature Sensor and raising the limits to 45C(on) & 35C (off)
  
• Analog Output VPDO Mapping 0x3200 3200h:  Other documentation says that Output 2 should be 0x2421 (cooling fan status).  I found Output 2 should be 0x24ff.  0x2421 is read-only and always shows 0x0C00 as a value.
• Analog Output (Contactor Drive) 0x6C11 6C11h:  Here you can change the output voltage of Pin 7/8 by changing the values for Analog Output 2.
• Analog Output Current/Voltage Mode 0x46A1 46A1h:  This controls whether the pins are voltage or current controlled.  This is set to 0x0 to set all outputs to voltage mode.
• Note: I attempted to measure the voltage across Pin 7 and Pin 8 before connecting the relay.  It showed almost battery voltage even though the controller was showing it outputting 12v on the Local IO Monitor on the Main tab of the Helper.  Once the relay was connected, it read 12.5v.  I suspect the voltage control circuit needs a small load to operate correctly.

After some initial testing, the controller turned the fan on at 45C and turned the fan off once the motor had cooled to 35C.

Here is the current working DCF (Sevcon Gen 4 Size 4 with Motenergy ME1616) file for reference.  LINK  This config also addressed many of the PMAC gain settings.  Seems to be very stable and drivable in 3rd gear.