Siemens Internal holding brake

Hi experts

I am doing a project involving Siemens Motor 1FT7068-5AF70-ABB0 with HOLDING BRAKE

Can some one please explain to me what is the function of Internal holding brake

How to activate it?

And is its correct to say that when the motor stop, the holding brake will applied automaticly?

(In the current project, the motor need to control a chain to move vertical down, pick up load then move up again, then hold load while another motor move the crane horizontally)



Thank you very much

I dont know the particular motor, but typically there is a small AC/DC converter in the terminal box for generating the DC voltage for the brake coil. The AC/DC converter is connected in parallel to the motor winding leads.
When the motor is supplied AC, the coil activates, lifting the brake thus releasing the motor to rotate.
When the AC is removed, the coil deactivates, dropping the brake thus stopping the motor from rotating.

If the motor is driven by a VFD for example, you cannot use the integrated AC/DC converter. In that case you must supply an external DC voltage (*) and control this in another way. Most VFDs can activate a relay for controlling the DC voltage.

*: You may have to either provide a DC voltage that matches the coil, or get a brake coil that matches the available DC voltage.

Just came to think of, that since the motor is used to move a load up and down, the control of the brake is definitely a safety issue.
Not an expert on the safety on cranes, so I recommend that you consult an expert and/or standards that applies specially to cranes.

When the power is off from the motor the rotor moves by a spring and the brake is activated. and yes it is a safety, so when no power brake is ON.
the only thing you have to watch is whemn using a VFD to control the motor,
Every hoist in cranes lifts etc must have this type of safety device.