PTO/Hydraulic Pump

[davidbrady]

I think Al is referring to the Sauer Danfoss Fan Drive Control Assembly (FDCA) part number: 1090223.

This is the device that takes a PWM signal from the DDEC and sends a proportional hydraulic signal to the hydraulic bypass on the fan motor.

It should be available thru: Berendsen, Sun Source, or Livingston Haven, and sometimes Ebay.

If I recall correctly, with the dash fan override enabled the PWM attempts to spin the fan at 1800 RPM but there's insufficient hydraulic flow to be successful. So instead it ramps up starting at 100 to 130% of engine RPM at idle going to 1800 RPM plus between 1200 and 1800 engine RPM's.

With fan override off, the fan spins significantly slower something like 30 to 40% of engine RPM.

-----------------------------some time ago I wrote this-------------------------

1) The Fan Drive Control Assembly, FDCA, (Sauer Sundstrand part, B5531-10354-207):
- takes a DDEC pulse width modulated input signal
- converts the DDEC signal to a proportional analog electrical current
- powers a solenoid to produce a proportional hydraulic pilot signal


2) The Flow Divider Valve on the side of the Hydraulic Motor:
- takes the pilot signal from the FDCA
- uses this pilot signal to control a hydraulic proportional valve
- the proportional valve diverts high pressure fluid around the fan motor

Essentially, we're taking a digital DDEC signal, converting that into a hydraulic pilot signal, and using this pilot signal to control high pressure high flow bypass at the fan motor.