Wiring of Papst Fans

Our team is worried about heat buildup in certain areas of our robot. Our plan is to have the 4 CIM motors to drive the robot, and the Victor 884 speed controllers for these motors will be all lined up next to the motors. I know that the Victors generate a significant amount of heat, and we have had problems with motors over-heating. The problem is further exacerbated by the fact that we’re effectively putting a “lid” on the whole system, by mounting the rest of the electronics directly above this. So, my first question is:

  1. Should we be worried about heat?


  1. If so, what should we do about it?

One possibility we are looking at is wiring up two of the larger fans to give this “hot-spot” more ventilation. However, I am confused about the wiring of the fans. I’m looking at the “Papst Multifan 4212 / 19H …] 12V DC 475 mA …] US-PAT: 5590235 5135363 RE34268”. As far as I can tell, this is slightly different but functionally the same as the one that came in the kit this year (“Compact Fan (Large) …] PN: 4112N/12GL-175”). The way this is wired suggests that it should be connected to a male 3-pin PWM-type cable on the Robot Controller (RC). Namely, it has the female end of the cable type on it. However, it does say “12V” and the RC supplies only 5V. In addition, I’ve tested it in Relay, PWM Output, Digital In/Out and Analog, and none of them make it spin.

Now, I would consider myself perfectly competent to clip the female connector and wire this thing up “by hand”, so to speak, but the way it is wiring seems to suggest otherwise. I understand that many parts in the Kit are not designed for FIRST per se, but looking at the website (www.ebmpapst.us) suggested that the PWM-type wire is not the default connector. Specifically, it says in the PDF, “Electrical connection through AWG 22 leads. Stripped and tinned.” So this is my third question:

  1. How do I wire these gosh-darned fans? There’s no good info on the site.

And just to sate my curiosity, if the answer IS “chop off the pwm connector and wire it”, then

  1. Why the flip is the PWM connector on there in the first place?

I think that’s all for now. If someone could link me another thread that answers this I’d be grateful, but save the “search before you post” talk please.

Thanks in advance,
Paul Dennis
Team 1719

The large Papst fans simply have an unusable connector on them. You can chop this off and find which is power and ground, and put it on a 12V relay, and it will run full bore all the time.

As for the fans on the victors themselves, you need to put ring connectors on them, and put those rings through the screws along with the 12V supply going to the victor.

The PWM connector on the victors is for connection to the computer.


Umm… Just use the kit fan. You’ll run into these Q&As, as any fan outside the kit has a non-KOP motor.

So the correct answer for question 2 is, “use the KOP fans.”

Thanks for the replies. I was basically just confused as to why they give you a connector that you’re just supposed to chop off… and why this was not accounted for in the spec page on the website.


The connector that comes on the fan is a standard connector in many devices. The manufacturers provide that mating plug on their power supply or where the supply enters the main board for the device. You need to cut this connector off the wire so that you can add the needed crimp on terminals.
The fan you were looking at that had three wires is used where the system must know that the fan is turning. The third wire is a signal wire.
You can wire to a Spike via a 20 amp breaker and control the fan from your RC or you can wire directly to the breaker so that the fan runs whenever the robot is turned on.