[gardon]

Hi All,
Am really baffled by a problem with a tornado 210. Keep getting axis overhead alarm, but servo motor is cold. Have replaced motor but am still gettin alarm intermitadly so am persuming the cable could be the fault? anyone know if my train of thought is right and if so, best place to get a cable?
Any help appreciated

[Al_The_Man]

Servo motors are often fitted with temp sensors, if motor has been replaced, check the wiring to it.
Al.

[keebler303]

Normally there will be a thermal switch inside the motor. At some temperature (80C) or so, it will open. You can defeat the sensor by installing a jumper wire between these two terminals on the controller. If that fixes it, the problem is most likely your wiring.

I am not sure how old your hardware is but some drives have a software thermal protection scheme. This works by knowing the characteristics of the motor. For instance if the motor draws X current for more than Y seconds, it will know this has made the drive too hot and will fault. The first idea is probably much more likely.

Matt

[gardon]

Thanks for the help guys! machine is 10 years old and servo motor is a fanucc, it's a sealed unit mostly, but i've had it checked out and on a diagnostic run for 48 hours and seems to be perfect. i do have a break in the cable to the motor and have re-joined theese cables but it's still a little tempremental. a replacement cable from manufacturer will take 3 weeks for some reason...any ideas where might get one faster?
many thanks again!

[Al_The_Man]

I usually make all my own cables up, Here I can usually get cable and connectors next day.
Al.

[NICK1945]

Hi Gordon
If you open the encoder cover there are two white wires small gage going to the motor this is for the thermal switch normally closed you can check with a digital voltmeter they should read zero ohms. Those wires go to the servo amplifier so you can check the cable for continuity.