ESC wiring sequence to motors

[DonRhone]

Hi, am just putting a FMS RocHobby plane together now.

I have a question on the wiring sequence between the ESC unit in this plane and the motor.

For what ever reason the ESC and the Motor were not connected when I bought this plane.

I just noticed that the ESC has each wire/connector labeled, A, B and C.

I have checked a couple other FMS planes to try to determine the sequence of the colours of the wires on the motor to the connectors on the ESC but can not see clearly the wiring between the motors and the ESC units.

In which order are the Red, Yellow and Black wires connected? Please advise.

[WintrSol]

Re: ESC wiring sequence to motors

Essentially, you have a 50% chance of getting it right. Just hook them up and test, without a prop, and see which way the motor spins. If it turns the wrong way, reverse any two of the three wires.

[FLY BOY]

Re: ESC wiring sequence to motors

Ug, I'll pretend I dint just read about switching any of the 3 wires. I know a guy who did that and smoked his esc. For what its worth I have a simple method. Red is always power, black is always ground, and what ever is not black or red, is signal wire. If all the leads are one color, sometimes they are, Find the red batt lead wire on esc, follow it to other side of esc, that's your red lead that plugs into the motor. Same for black lead. The middle wire off the esc to motor is always signal in my experience. If the motor spins the wrong direction, it ok to switch the red, black leads to the motor which will reverse motor direction. Same if motor leads all one color, Middle wire off motor always connects to middle wire esc. My buddy hooked up red to signal and fried his esc and his receiver. So I hope this helps. Happy flying<smiley image="smiley_good.gif"/>

[WintrSol]

Re: ESC wiring sequence to motors

I assumed the OP could tell the difference between the battery wires, on one end of the ESC, and the three motor output wires, on the other end.
ESCs work nothing like you describe; the red and black battery leads go to a set of output transistors, arranged in three pairs, with positive to one end three transistors, and negative to the other end of three transistors. The three motor leads connected to the point that each pair connect together. These pairs of transistors can apply positive voltage to one of the motor leads, by turning on the transistor connected to the red battery lead, while another transistor applies negative to a different motor lead. The ESC then activates different pairs transistors, and so applying power to two different motor leads, causing the motor to step to the next position of the magnets. Following the red lead to one of the output leads is just nonsense, since it leads to all three, just as the black battery lead leads to all three. Also, how do you know which is the middle motor wire? Motors are AC wound, so there is no 'middle', just three phases; the order the wires exit the back of the motor is pretty random.

[DonRhone]

Re: ESC wiring sequence to motors

If it is so simple as WintrSol indicates I would not have posted the question.

I certainly did try to trace the battery wires back, but once they hit the printed circuitry I am lost.

There are small circuit boards over circuit boards. enough to confuse me.

As one poster has already indicated, playing trail and error resulted in one burned out ESC.

I would not think Motion RC would want me playing trial and error, but if they are willing to stand behind what they sent me then I guess that is the route to go.

Will Motion RC who sold me the plane which came with the disconnected ESC agree to replace the ESC should I guess wrong.

Do I hear any one from Motion RC agreeing to send me a new ESC should my guess in the order of the wiring lead to a burned out ESC?

[WintrSol]

Re: ESC wiring sequence to motors

It is that simple; just don't confuse the battery wires with the motor control wires, which is what fried the system by the friend of the other poster. The motor is a 3-phase AC wound motor, and reversing it is as simple as swapping two motor control wires. The ESC pulses the three inputs to the motor in a specific order, and that order determines which way the motor turns. Except for a few ESCs which can be reversed through a setting in the ESC programming, the order is fixed.

BTW, I've been an electronics engineer for 40 years, and am very familiar with how the sequencer in the ESC works.

[doctormike]

Re: ESC wiring sequence to motors

Thank you, wintersol. I have never had a problem with switching any 2 leads to get the correct motor direction. It's simple. That's what all the instructions tell you to do. The Doctor