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Discussion Starter · #1 ·
Ok guys i got a motor for a roll up style door that i have a question about. It has a built in braking system on and the instructions say to release the brake hit it with the nameplate voltage{more or less].
The question i have is since this project is not precision required could i just hook 24 volts dc all the time and not have to worry about the brake at all?

I understand how dc braking works just not what to do in this application
 

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Ok guys i got a motor for a roll up style door that i have a question about. It has a built in braking system on and the instructions say to release the brake hit it with the nameplate voltage{more or less].
The question i have is since this project is not precision required could i just hook 24 volts dc all the time and not have to worry about the brake at all?

I understand how dc braking works just not what to do in this application
It sounds like it is not DC Injection braking if that's what you were thinking, it appears it is a Mechanical Brake that may or may not have a DC solenoid. Those usually have their own built-in rectifier that is tied to the motor AC winding connections so that as soon as you energize the motor, the brake is released. If you choose to do that separately, you can, but do not ASSume anything about the brake coil voltage, look it up, and also make sure you disconnect the internal wiring from the motor windings so you are not back feeding the motor. If you do that, you can usually just apply AC to those same internal connection points and use the built-in rectifier. Remember to then separately fuse your brake circuit.

But if your purpose is to use this motor WITHOUT the brake, then just remove the brake and be done with it. Keeping it energized forever is just inviting failure over for a future unannounced drop-in dinner date.
 

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Discussion Starter · #3 ·
Yes after looking the motor over it is more of a clutch then a brake. The wiring diagram called it a brake. After talking with my boss about it we decided to use it as a back up stop. now it is just a matter of writing the program for it.
 

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Yes after looking the motor over it is more of a clutch then a brake. The wiring diagram called it a brake. After talking with my boss about it we decided to use it as a back up stop. now it is just a matter of writing the program for it.
You are controlling a roll up door with a PLC? What type of system is this a part of, I've never really seen that before.

Actually I lie, they had one such door at the lead smelter going into the scrap yard to keep dust in the building.
 

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Yes after looking the motor over it is more of a clutch then a brake. The wiring diagram called it a brake. After talking with my boss about it we decided to use it as a back up stop. now it is just a matter of writing the program for it.
Clutch??

Well, maybe you are interpreting it that way.

A motor brake is like a clutch in that it is a series of pressure plates that are held CLOSED by spring pressure. Then there is an electrically powered solenoid that RELEASES the pressure when you energize it, which allows the motor to spin. That way as a safety feature if you ever LOSE power, the brake is automatically applied.
 

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Discussion Starter · #6 ·
It was an old Rytech roll up door for a freezer. The control board had a meltdown and rather than buy a new door the boss decided it would be a good chance for some plc training. The program is very very simple. Just uses a Mircologix 1100 and few buttons (up down and estop) with saftey eyes incase someone walks under as it goes down. Nothing to fancy.
 

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Discussion Starter · #7 ·
Just an update, I have a working program and door. Everything works like it is supposed to. Thank you for the help guys.
 
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