What else can cause F1?

If you have reviewed and performed the steps in the relevant questions above, you can also investigate the following potential causes of an F1 code:

1. Sometimes electrical noise can be induced on the motor leads from other wires that run alongside them, such as brake leads. When the brake operates, the noise from the arcing in the brake contactor can trip out the drive. This failure can be ruled out if the drive does not fault out at the instant the brake contactor switches. Solution: Run motor leads in a conduit separate from other leads.
2. (Ramp mode only) If the F1s happen after reversing direction or stopping, then quickly starting again—for instance when inching/spotting. The trip may be due to starting into a spinning motor. Solution: Don’t start into a spinning motor. If the motor is spinning because the brake is setting slow, then use the dead time parameter (L26 on CX/MSM) to increase the amount of time the brake has to set before the drive will start again.
3. (Coast mode only) If the F1s happen after reversing direction or stopping, then quickly starting again—for instance when inching/spotting. A slow mechanical brake on a Hoist may not be able to stop the motor before the Micro-Speed® is signaled to begin powering the motor again. This effectively causes the Micro-Speed® to start into a spinning motor. Solution: Increase the dead time parameter (L26 on CX/MSM) to increase the amount of time the rotor has to lose its magnetic field. Usually 1.5 seconds is more than sufficient.
4. Residual magnetic field in rotor. The drive may trip out if the drive begins to power the motor too soon after it has stopped (this cause is rare). Solution: Increase the dead time parameter to increase the amount of time the rotor has to lose its magnetic field. Usually 1.5 seconds is more than sufficient.
5. Some mechanical device in the drive train is not made for use with a variable frequency drive. For instance, some mechanical soft-starting devices or clutches will not operate when driven at less than full speed. On a hoist, sometimes the load brake may be installed incorrectly.
6. The load is too large for your motor/drive system. Solution: Reduce load or increase motor and drive capacity.
7. Certain kinds of Nema type D motors produce a lot of slip at low frequencies and may not budge a load until it ramps up to a fairly high frequency, sometimes 30Hz or more, at which point the drive will trip out. This slip cannot be completely eliminated, but it can be reduced. First, try lowering the voltage peak function (L21) and see how the machine works. Do not lower the voltage peak function to less than 90% of its nominal rating. Recall that the nominal voltage peak setting is (Incoming Line Voltage) x (full Hz of motor)/(full motor voltage). Then try changing the voltage boost gradually, first by increasing and if that does not work then by decreasing (increasing is usually the most effective method in this case).

Back to General F1 Help.