[Newbie] Help me decipher wiring diagram.

[RJSakowski]

The colored block is the motor control and the coil is depicted as the same color. I'm guessing the relay is within the control.

Isn't this mainly for safety and holding position without overheating?

The OP stated that this circuit was for the spindle. A brake used on the spindle is for quickly reducing spindle speed. My Tormach CNC mill uses a braking resistor for the spindle VFD.

 

[mksj]

Without having further details on the controller used, what is being used for a brake and the application/purpose it is hard to give a better response.. If there is use of ball screws that would require a brake when stopped, the use of a separate electro-mechanical brake on a lathe is a question. Some machines have a brake motor or electro-mechanical brake, the brake is activated when the motor shuts down or the clutch drive is disengaged. How it is used and wired up depends on the application and the, means of braking. Some servo drives with encoders also have the ability to brake electronically. Lack of information results in conjecture, please be more specific/detailed in your application.

 

[higgite]

Since we’re speculating, my best guess for why the manufacturer uses a 2-pole relay in the brake power supply circuit is to make sure no voltage source is connected to the brake when the controller calls for the relay to open, regardless of polarity of the customer’s 24VDC power source. But, that’s speculation on my part.

Tom

 

[xbartx]

In an earlier post I mentioned this is for a lathe spindle and bought the servo with a brake thinking it was needed like the DC motor it was replacing. If I do ever need to utilize the brake I'll rework the setup I have now. Since I don't really need my controller or the servo controller doing any of the on/off function of the brake, I used a empty pole on my contractor which feeds the 24V for the brake.
If that looks problematic, feel free to let me know!
-Brad

 

[durableoreo]

For normal breaking operations, a resistive brake is usually used. A physical motor brake is probably more of a hold type function.

Anyway, you can just leave it disconnected if you don't need the function

 

[xbartx]

Anyway, you can just leave it disconnected if you don't need the function

The brake is on by default and only releases with being energized with 24VDC

 

[Chip Hacket]

Yea, going to need to power the brake so it will release