Today we will talk about this "Alarm 11” in the end to remind what it is behind the common fault is, and how to step by step to find out, repair.
"Alarm 11” in the End What Is the Problem?
In our contact with Fanuc α and αi series servo system, "Alarm 11” is a very common alarm code. What it is, is that the
Fanuc servo amplifier has detected an abnormally high current. This current is not supposed to be there, but it is, either because there is a short circuit in the drive, or because there is a problem with the motor or cable.
It corresponds to an explanation that generally looks like this:
* Servo amplifier overcurrent.
* Abnormal current detected.
* Possibility of an internal short circuit.
To put it bluntly, the system is self-protecting itself from making the problem worse.
What Are the Common Causes of Failure?
When we encounter "Alarm 11” in maintenance, we can mostly find the causes from these directions:
* Short-circuited motor coil (e.g. burnt winding).
* Broken servo cable, leakage, poor grounding.
* Bad IGBT module inside the amplifier.
* Unstable power supply, interference.
* Wrong parameter setting, abnormal pulse signal.
* Cooling fan failure, heat accumulation.
If you're not sure, you can't fix it, and it may get worse.
How to Troubleshoot? We Generally Do This:
1. First power off, naked eye check the line
Don't rush to dismantle the device, first turn off the power, and look carefully with your eyes. Check the motor wires and encoder wires for wear, poor contact, burn marks or loose shielding. Sometimes a bad wire can make a big trouble.
2. Check the motor with a megohmmeter
We are accustomed to using a megohmmeter to measure the insulation of the motor. A low resistance of the coil to ground may indicate that there has been a short circuit inside the motor.
3. Drive on the test bench to check (if available)
If you have a professional test platform (like the
Fanuc test bench we use Songwei), you can take the drive down separately to measure, to confirm that it is not a problem with the drive itself.
4. Swap method is also effective
Change a normal drive or motor to try - if the alarm is gone, it means that the original part has a problem. This approach is old-fashioned, but it works.
5. Do not ignore the heat and power problems
Some customers have too much ash on site, the fan does not turn, drive hot and hot; there are also unstable power supply voltage, frequent fluctuations. These may indirectly trigger "Alarm 11”.
Repair or Replace? Don't Be in a Hurry to Decide
Not all Alarm 11 means "scrap”. In many cases, a small problem can be fixed and the unit will still work:
* Replace the fan with a new one.
* The cables can be rewired and the solder joints cleaned up.
* The amplifier's IGBT module can be replaced.
* The driver board is sometimes just desoldered or dusted.
At Songwei, we don't recommend replacing the whole unit right off the bat. We have:
* Driver testing service.
* IGBT module repair.
* Circuit board soldering repair.
* Cleaning calibration + on-board testing.
If you really need to replace it, we also have original and refurbished parts in stock and support fast shipping.
A Real Customer Case
We have a customer from Europe, one of their machines jumped "Alarm 11” every now and then, the local technician changed the amplifier but it didn't work. The local technician changed the amplifier but it didn't work. Later, he sent it to us for testing and found that the problem was not in the driver at all, but the insulation layer of the motor cable was broken, which led to the leakage of electricity to the ground. Replaced the cable, the problem was solved immediately, and the customer almost spent thousands of euros for nothing.
How to Prevent Similar Problems in the Future?
These small habits can greatly reduce the probability of alarm 11:
* Measure motor insulation quarterly.
* Cables should not be twisted or near metal edges for long periods of time.
* Blow dust from fans and filters regularly.
* Allow space for heat dissipation when the drive is installed.
* Add a surge protector, the voltage fluctuation will be much less.
After all, maintenance is far more expensive than prevention.
Don't Take It Personally, Talk to Us
If you have a "Fanuc Alarm 11” problem on your hands right now, or if you've had it repaired a few times and it's still not working, then don't guess anymore. We can:
* Provide professional testing services.
* Support on-site or remote diagnosis.
* Drive/Motor repair.
* Original new or used parts are in stock.
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