[nordlichtFanuc]

Hi guys

As you may now, I have a quite old MV Junior (1987), which I brought back to live, from some defective hardware (masteboard, memory board).

The machine is mostly running good and does produce accurate parts...
But sometimes is does do me some nasty stuff.. Maybe you have an idea on where to look:

The biggest problem:

Sometimes (lets say once a month) when the machine is running, the control suddenly shuts down completly (like you press the red button, to shut down the control (not the e-stop)).
Its like the machine does power off.. Screen is black. The are no blown fuses and the cabinet is still powered.

A push to on the green button, restarts the machine as usual. No problems other than dealing with the afthermath of this sudden powerloss.

This as very annoying, as I never know when this will happen. Mostly I have seen it though, on the following occasions:

1. During a tool change (when the arm motor is powered)
2. In Rapid Moves at 100% rapid speed

It does seem like the is something tripping, because of overload, which will cause the machine to power down. But what can that be?
Could it be somthing from the power off switch itself? Like a faulty contact? Can anydoby explain me how the power on circuit is done? With a self holding relay?
Could it be issues from our power outlet? Its 32A 400V and then going into the cabinet, then to the external transformer.

I find it kinda strange, that it happens on two totally unconnected occasions..

Thanks for any advice

[John_B]

I think the circuit you have that wired into might be a bit weak, could be you're getting a brown out condition. Memory serves that you might be 20 amps or so low.

I ran one for years that had issues with the power board. Had it repaired several times and it ran for 9 months or so before giving the same problem.

Nice machines...

Sent from my SM-G965U using Tapatalk

[nordlichtFanuc]

Hi

I have 400V 32A three phase power. Which can deliver a 22kVA.

Machine takes 16kVA according to the manual..

Should be enough I think..

[freakycnc]

Hi NordlichtFanuc,
Have you checked the LED's on the "Power Input Unit"? It may have a clear cover on it with two thumb release fasteners.
It should normally have a " PIL" lamp on that's green. If the control power supply goes into alarm it will shut off the 200VAC to the power supply.
The red LED "ALM " will be on in this case.
Check the secondary side of the control power transformer to make sure it's at at least 200VAC.