Wire Colors - 603-1549-ND

Wire colors on a 603-1549-ND. Trying to replace a small fan with the 603-1549-ND. Some of these small fans have 3 wires, red, black, white. Some of these fans have four wires, black, red, white, blue. Can a 4 wire be used in place of a 3 wire? Is the white wire typically always a tach output?

Thank you,
Steve Duncan

Welcome sduncan,

The best I could say is that in most cases, you could replace a 3-wire fan with a 4-wire one because the 3rd wire is usually a tachometer output, and the 4th wire is usually a PWM input wire. Unfortunately, that is not always the case. Furthermore, other than red and black consistently being used for Supply+ and Supply-, respectively, there is no standard color coding for the other wires.

That answers my question. I have seen pictures that had red, black, and blue, but said the blue was frequency or tach output, and other motors with 3 wires, have listed white as the tach output.

Thank you,