Spal fan wiring questions

[Efi69Cam]

Has anyone wired dual Spal fans in the series/ parallel arrangement with three relays for two speeds with both fans going at the same time?

[jwillia2]

I just went through this http://uploads.tapatalk-cdn.com/20160720/1cf04a011925716850c4198f455b7feb.jpg

[Efi69Cam]

Thanks for the diagram, its easier to decipher than the service manual.

Have you run spal fans in series? What I'm a bit concerned about is whether or not the motors are good running on 6 to 7 volts.

[jwillia2]

Thanks for the diagram, its easier to decipher than the service manual.

Have you run spal fans in series? What I'm a bit concerned about is whether or not the motors are good running on 6 to 7 volts.

i don't see any issues. also they made a variable speed controller for their fans thats doing the same thing. just reducing the voltage to slow them .

[roger1]

i don't see any issues. also they made a variable speed controller for their fans thats doing the same thing. just reducing the voltage to slow them .PWM controllers like the Spal sells don't reduce voltage to control motor speed. Pulse Width Modulation is a controlled high speed switching control that varies the amount of on/off time (pulse width) to the motor.

That said, I don't believe lowering the voltage to a brushless DC motor reduces it's life. Like has been pointed out before, GM used a series/parallel system for 2 speed operation for may years.

[130fe]

Does anyone have a good schematic for wiring in 2 fans (with PCM fan triggers) and a trinary switch using 3 relays?

[Larry R]

http://i563.photobucket.com/albums/ss72/ldrollow/fan%20schematic1_1.jpeg

This schematic is the way my two Spal fans are wired. I am using two engine mounted temperature switches of different values to operate the fans; lower temperature controls series wiring and higher temperature controls parallel wiring. I don't see why one couldn't substitute a PCM source in lieu of the two temperature switches. This system works well.