Bimba OLE - Manual (Page 20)

18
Inspect the motor and rotate the shaft when the motor is not connected.
If you feel any rubbing or there are any dents on the motor, there is prob-
ably an alignment problem and the motor may need to be replaced.
If the rotor was removed from the stator, it could have been demagne-
tized. The motor would need to be replaced.
If you still cannot solve the problem, the size of your power supply (volt-
age output) may need to be greater. When a step motor rotates, it acts
like a generator pumping voltage (back EMF) back into the drive. Back
EMF rises as motor speed and inductance increase and can cause a
stall. The solution is to either change from a series to a parallel connec-
tion (series connections quadruple inductance) or use a power supply
with a higher output voltage.
Problem: The motor doesn’t produce any holding torque.
Solution: Make sure that line power is on, the drive is powered up, and
the motor phases are connected correctly to the drive.
Problem: The motor (actuator) oscillates back and forth at low speeds.
Solution: This is due to resonance, common between 1-4 rps. If this is
observed with no load, add a load to the motor (the load will dampen out
resonance). Changing from full-step to half-step or microstepping will
also solve resonance problems.
Step and Direction Drives
Note: Please read your manual first before and during your setup. Bimba
manuals, available at www.bimba.com/OLE/manuals, are short, to the
point, and comprehensive.
Problem: The drive’s power LED does not illuminate when power is ap-
plied.
Solution: Check the fuse and replace if necessary with one of the extra
fuses included with your drive. If you have no fuses or continuously blow
fuses, call Bimba Technical Support. Check your power supply to be sure
it is not providing an excessively high voltage to the drive.
Problem: The motor runs then suddenly dies. The connections are cor-
rect.
Solution: Turn off power. Refer to your motor wiring diagram. Discon-
nect the motor. Using an ohmmeter, measure the resistance between the
A+ and A- and B+ and B- terminals. The reading should be in the mega-
Ohms. If resistance is low, the H-bridge is damaged and the drive must
be returned on a RGA (Returned Good Authorization). If the resistance is
normal, inspect the board for any visible damage to the components and
check the motor for a short circuit in the windings.