Fanuc Beta servo motor thermal alarm 430

To All;

We are having a problem with a Fanuc B2/3000 servo motor in a bar feeder. It runs for a few hours and then stops with a 430 Thermal Alarm. The motor itself is not getting hot, it measures ambient temperature (82 F) when we check it. I believe that the Beta motors and drives are a "low cost" system and the motor temperature sensor is either on or off. Does anybody know of anything that we can check to verify the problem? I am stuck between the people that installed the bar feeder who seem unable to diagnose the problem, and a local knowledgeable firm that does not want to get involved directly while the other company is still trying to sort it out. If someone knows what pin on the motor connector carries the thermal alarm signal I could check it in a non-alarm and an alarm state. If the temperature sensor is defective, I would be willing to temporarily bypass it so that we can keep running. Thanks in advance.

Glenn at Metro North

Is this "axis" visible on the CNC control, or not? If so, you can access one of the parameter screens on the CNC control, and see motor temperature, encoder count, % load, etc, on each axis.

I'm guessing that since its on the bar-feeder though, that it's probably not visible on the CNC side.

The position of the axis is visible on the CNC screen but the System, Diagnostic information which shows motor and encoder temperatures is not displayed. I believe, and I may be wrong, that Beta motors have a "make or break" function to temperature control. If I can find information on encoder pin-outs, I can verify if a temperature error code is being sent from the motor.

Thanks, Glenn

metronorth said:

......I believe, and I may be wrong, that Beta motors have a "make or break" function to temperature control. If I can find information on encoder pin-outs, I can verify if a temperature error code is being sent from the motor.

Click to expand...

Per my Beta series description manual....

"NOTE
1 Heat protection is not defined for b0.5/3000, b1/3000,
b2/3000, and b3/3000."

Looking at the connections diagram, it shows no thermal switch connections for the motor.

The only thermal protection I see for the B2/3000 system in on the regenerative braking unit (if used).

This is the text related to that...

"NOTE
If the separate regenerative discharge unit overheats, its
built–in thermostat will trip; the external overheat alarm is
issued."

The thermal switch is connected to the amplifier at CX11-6 TH1 and TH2.

If no separate regen unit is used then there should be a jumper on those terminals.

Vancbiker;

The regenerative braking unit is not used and there is a jumper on the TH1 and TH2. Any ideas on where the 430 thermal alarm would originate?

Glenn

When you get the alarm 430 on the CNC, is there a lower case o displayed on the Beta amplifier? If so, then the alarm is indicating the amplifier has overheated. Bad fan maybe?