How to Protect Servo Motors Against Burning?

Yo Signode,

Let me pls quote you,

quote:

'We just have a thermostat switch inside the motor and in most of the motors, this switch don't work.'

unquote

The thermostat does work , it only isn't fast enough in case of a FULL short circuit

Quote:

'Two days before, the winding of two motors burnt due to a mechanical obstruction in tools during a calibration process and no one took notes that why tools stopped.'

Unquote.

And you call that a Calibration Procedure ?

Pls Signode, the First step in a Calibration Procedure is a checklist !!

Off course you have Qualified Calibration Personnel

ON this list is FIRST that the to be Calibrated Equipment is totally FREE of ANY obstructions.

Also on the Calibration list is a note_field for the Qualified Calibration Technician in which he HAS to fill in all the snags he encounters. This goes then to Punch List and when Punched from the list , the Calibration Procedure starts over again.

Want me to go on according to QS systems?

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Solution

Build in some fuses according to manufacturers specifications for each motor

Make sure these fuses are marked with an 'F' the 'F' for FAST. Eventually you can build them into the the outgoing terminal strip as mentioned below. You can use simple 20x5 mm fuses. (the 'F' type pls)

Fused terminal

TTYL T L.

How old and antique are these drives that you are using with the Parker motors? I have worked with many brands of servo controllers over the years, stretching back to the 80s and don't recall any that did not have an overcurrent protection scheme of one thing or the other. Someone needs to do some proper system integration work on this setup.

If these drives truly do not have an overload function on them, dump them and get new ones. The costs you save on not replacing burnt motors will pay for the project pretty soon I would imagine. For one truth of the manufacturing area is... stuff will fall and block machine tool travel, it s a fact of nature.

Actually at the start of every first shift, operator clean the machine and then set a command which we call "Calibration or Reference" in which all the tools travel to the operator side, then go to drive side and then set at a fix distance. That whole procedure calls "Calibration". After this operator set a job but don't need to calibrate again before setting another job. Calibration just needs to remove the errors in setting.

I want to add a protective device in between motor and drive but don't know what to select.

I find it hard to fathom that any servo controller that is anything more then just a brute force power supply has no overcurrent protection built in to it. What is the data on those controllers (make and model)?

usually the servo motor has three poles UVW, so u can simply measure the current on each and install a fuse, the value of the fuse should be the same of the reading of current on the maximum load where the fuse should be T type . if u want to use F type fuse then the value should be one and a half of the max current.

There are chips around for this purpose, they monitor the motor current and if it exceeds a preset level (200% is a good starting point) they signal an error. This works far faster than any thermo switch can.....

This signal can be used to drop power for all motors and trigger an alarm......

Search on the web.....