I have had this 95 vf-0 for a year. Now all of a sudden im getting a over voltage alarm (119).
I'm running a phase convertor .

Would this be something with the machine itself or is it my incoming power supply?.

Any places to start to look ?. Im going to get a electricion to check my incoming voltage again.

Thanks

Measure the voltage between phases if there is one that is way-out then you'll probably find a capacitor is faulty in the phase converter.

You can get an overvoltage alarm whether the machine is running or not from the incoming power being too high; this pushes the DC voltage too high.

If your incoming phases are out of balance you may get an overvoltage alarm or you may get a phase loss alarm.

If the overvoltage alarm occurs when the spindle is stopping it is probably because the Regen resistor is not coming into action. Braking the spindle pumps up the DC voltage and when it reaches a particular point a circuit closes to dump energy into the Regen resistor and stops the voltage going any higher. If the voltage sensing circuit is faulty then the circuit never closes and if the resistor is burnt out then it never dumps the energy.

Check for continuity through the Regen resistor the resistance is quite low, maybe around 8 ohms. The value has been quoted in some posts but I cannot remember it exactly.

we tested the power going in to the phase convertor and at the machine. It all tested out good.

Geof were do I find the regen resistor on the machine?

I also seen were you post this before "

This sounds like an open circuit on the braking resistor. That is the thing inside the cage on top of the machine that gets hot.

When the spindle slows down or stops it does it by rgenerative braking and the controller dumps power onto the DC buss. When the DC buss voltage goes above a certain level the braking resistor, also called the regen resistor is brought into the circuit to bleed off excess voltage. I think there is a relay somewhere that is supposed to close.

If, for some reason, the circuit to the regen resistor does not close the bud voltage goes up and triggers and overvoltage alarm."

Can you whatch the dc buss to see if the regen resistor maybe faulty?

.....Geof were do I find the regen resistor on the machine?

..... Can you whatch the dc buss to see if the regen resistor maybe faulty?

The resistor is the thing on top of the control cabinet in a metal screen.

You should be able to go to the DIAGNOSTICS screen (Push the PARAM key twice) and then page down and find DC BUSS VOLTAGE. I don't have any 1995 machines so this may not work.

When(If) you find the DC VOLTAGE try starting and stopping the spindle while watching it. You should see it drop on start and go up on stop. Do this for various speeds and see if you can trigger the overvoltage alarm. On my machines the DC voltage peaks out at about 380 when the spindle is topping from a high speed but I have no idea if this will be the case with yours.

I watched the DC BUSS it reads normally around 170-177 with the spindle running. When the over voltage alarm goes on it reads around 181-182.

Do you think it could be the regen resistor?