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Fanuc servo amplifier fault

poxino

Aluminum
Joined
Jan 11, 2017
Hello guys,

I am having problems with my servo amplifier unit on my machine, it's related to the pallet changer.

I am having a servo alarm on my control 414 ( on PMM screen), and a letter P on the little display of the servo unit in the electrical cabinet.

I managed to check voltage , which looked what it should be, but that's about it.

What else could I do/ check?

I can't clear the alarm because of this problem , hence I can't run the machine.

Any suggestion is highly appreciated
 
What kind of servo drive is it?

For alpha drives (alpha i and beta might be the same or similar):

1: Communication error between the amplifier and module

2: Cause and troubleshooting:

(a) Check the connecter and cable (CXA2A/B)
(b) Replace the control printed circuit board
(c) Replace the SVM
 
What kind of servo drive is it?

For alpha drives (alpha i and beta might be the same or similar):

1: Communication error between the amplifier and module

2: Cause and troubleshooting:

(a) Check the connecter and cable (CXA2A/B)
(b) Replace the control printed circuit board
(c) Replace the SVM

Hi checked the connectors on the beta servo amplifier

I couldn't see any difference.

Would replace the control printed circuit board be an expensive fix?
 
When it says to replace the PCB, I'm not entirely sure *which* board it is suggesting. Maybe someone else has more knowledge of that.

When you said you checked the connector on the amp, did you also check the connector to wherever that goes? (Probably the CPU).

Not sure how your system is laid out. If it is anything like the 15mb I'm pretty familiar with, there might be an axis card plugged into the Main CPU that is for the pallet changer servo, and that might be what PCB it talks about.

Pretty sure it means replace the whole drive when it suggests replacing the SVM. You could check on ebay to get an idea of price for that.
 
Since you have a PMM, I'm gonna guess that this alarm is on a beta drive. Here is the text from my documentation about alarm P on a beta drive. I've never come across this alarm so just going from the book....

This alarm is issued if the DC voltage in the main circuit
power supply is abnormally low. This alarm is also
issued if the circuit breaker has tripped.

Check the supply voltage leg to leg at the amplifier. Should be 200-240. If that is OK then likely the problem is internal to the drive. Typically beta drives are not field repaired, just an exchange item.
 
Since you have a PMM, I'm gonna guess that this alarm is on a beta drive. Here is the text from my documentation about alarm P on a beta drive. I've never come across this alarm so just going from the book....

This alarm is issued if the DC voltage in the main circuit
power supply is abnormally low. This alarm is also
issued if the circuit breaker has tripped.

Check the supply voltage leg to leg at the amplifier. Should be 200-240. If that is OK then likely the problem is internal to the drive. Typically beta drives are not field repaired, just an exchange item.

Checked the voltage and it was about 240v.

The drive might be gone then :( , and my laptop has just gone as well
 
I did replace it yes!

Hello there

I got a quote to repair the servo amplifier unit.

Now the next step would be to take the servo unit out.

Now is this just a simple unplugging process , and undo the screws that keep the unit attached to the electrical cabinet , or is there something else involved?

Thank you guys for the help as usual
 
Since you have a PMM, I'm gonna guess that this alarm is on a beta drive. Here is the text from my documentation about alarm P on a beta drive. I've never come across this alarm so just going from the book....

This alarm is issued if the DC voltage in the main circuit
power supply is abnormally low. This alarm is also
issued if the circuit breaker has tripped.

Check the supply voltage leg to leg at the amplifier. Should be 200-240. If that is OK then likely the problem is internal to the drive. Typically beta drives are not field repaired, just an exchange item.

Would you know what is involved with unplugging the servo amplifier unit?

Is there something I need to pay attention at?

How do I basically take the unit off?

Apologies for the newbie questions :)
 
Remove the plugs making they are labeled in a way that will let you put them back correctly. Then it is just a matter of removing 2 or 4 screw holding the drive to the back panel. By disconnecting the drive it will lose the battery backup if it has an absolute encoder for the motor. You'll want to be sure you know the machine builders procedure to reset that when you install the new drive. The drive parameters are stored in the CNC or PMM and downloaded at power up.
 
Remove the plugs making they are labeled in a way that will let you put them back correctly. Then it is just a matter of removing 2 or 4 screw holding the drive to the back panel. By disconnecting the drive it will lose the battery backup if it has an absolute encoder for the motor. You'll want to be sure you know the machine builders procedure to reset that when you install the new drive. The drive parameters are stored in the CNC or PMM and downloaded at power up.

I managed to take it out, many thanks!
 








 
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