F276 “What do you mean, it moved?”

f276

F276 is a movement error on units that have absolute encoders. The short story is that the drive stores the position of the motor as it shuts down, and then compares it to the position of the motor when it starts up. If the value difference is larger than the value in P-0-0097, it throws a F276 and waits for a human to come over and make sure things are okay.

This can also happen if you are just installing a motor and try running it without setting the absolute position, but that is a no-no to begin with. If that’s what you’ve done, don’t do it again. If you’re not stepping outside the bounds that much, read on.

Fixing the Rexroth error F276

The F276 is easy to fix. Just check the displayed position to make sure it’s showing the actual position and then hit the S1 permissive button. This resets the error window and allows the error to clear. Make sure the machine is safe to run from the current position and you can try running again.

This error isn’t always a big problem. It depends on the machine. When it’s a problem, though, it can be a serious problem.

Some machines (mostly CNC units with vertical axis) cannot recover from the vertical axis slipping downward. It puts a tool in the work or causes some other (usually catastrophic) problem. This error lets you know something has moved (brake failing perhaps?) and then makes sure you tell the drive it’s okay to run. This allows you to jog the offending axis out of the way before normal startup, if required.

Can’t fix it? Replace it

Another situation that can cause this error is a bad position initialization. I have never personally seen this error trip from a feedback error/failure. Usually one of the 50 other feedback errors nails the problem first. However, if that is the problem, you must replace the motor.

If you need to replace the motor, give us a call. We have the largest supply of factory refurbished emergency replacement units in the nation, and we will fly the unit to you and provide field support. This will minimize downtime.

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Factory Repair services available with 24 hour turnaround.
customerservice@hyperdynesystems.com

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