Wiring the fans

[Itamar]

Hello,
I wanted to know how can I connect the fans provided in the kit.
Am I allowed to connect the fans directly to the PowerDashBoard? to victors? to spikes?
and if so, which wire goes to where, because I heard the connection is different than a PWM.

[Teched3]

Which fans?

[Racer26]

The small fans in the kit are just 2 wires, +12VDC and Ground. You can wire them directly to the PDB.

The bigger fans have 3 wires. They are NOT PWM. They are +12VDC, Tach, and GND. The tachometer wire will allow you to measure the speed of the fan. In most FRC applications, this is totally unnecessary, and just supplying the fan with +12V and GND will be just fine. I believe the tach wire is the centre wire of the three.

[Teched3]

Which fans? The compact fans can be wired directly to the input power terminals if ATTACHED to the Victor speed controller (R60). Otherwise, it would seem they fall under the motor rules, requiring a breaker-protected spike or speed controller to operate each one. This is strictly my opinion, and you can ask the GDC if you want an official answer. Anyone else is welcome to chime in.

[fsgond]

For sure the ones on the victors can be wired to inputs of the victors, but no other fans can do this. This is a great question for the GDC, my past experience tells me that you would be fine, but it would not be good to get to a competition and have them make you change it. Everywhere that motors are mentioned, they do not mention these, so that would say that they do not have to be connected to a spike to speed controller.

[Jon Stratis]

There is no specific rule governing the fans, with the exception of the Victor fans, which may be attached directly to the power input terminals on the Victors.

That being said... In past years (which in no way applies to this year), this rule was absent. In its place, we had to connect the Victor muffin fans directly to the power distribution board, although we were allowed to join them all together under one 20A Spike. Teams impressed upon the GDC the safety and ease of connecting those fans directly to the Victor power inputs, and the rules were changed (starting in 2009, i believe... maybe even with a Q&A in 2008).

Using that as a precedence, i would think connecting the fans directly to the power distribution board would be acceptable (protected by a 20A breaker, of course).The fans are very low power devices, designed for moving air through an area with the intent of cooling components. Having them controlled by a spike defeats that purpose, unless the spike is triggered with a temperature sensor placed on the concerned components. Rather, having the fans on whenever the robot is on makes the most sense.

But that is all just my opinion. Please request clarification from the GDC