121
Diagnostic Solutions
Item # Check/Solution
Verify correct Machine Data
(LN) parameter settings.
The Machine Data parameters are used as a scalar to translate the
command speeds programmed in FPM to an rpm value used by the
drive. Incorrect setting of the machine data parameters may cause the
command speed in rpm to be too high or too low.
For example, if a machine has a 1:1 roping ratio, then setting this
value in the drive as 2 (:1) will cause the speeds to be calculated as
twice as fast.
If the Motor (Encoder) Speed matches the Command Speed (rpm),
but the calculated Elevator Speed or the actual speed measured by
hand tach (FPM) are slightly off, then the Machine Data can be ad-
justed slightly so the numbers agree. This would typically be done
by adjusting the Gear Reduction Ratio (LN02) or the Traction Sheave
Diameter (LN01).
Refer to Determine the Correct Motor Speed in RPM for further details.
Encoder/Motor Pole Position
Incorrect
For PM motors, the absolute encoder position is used to properly in-
dicate the position of the rotor. If the connection of the encoder to the
motor shaft changes (removed/replaced, slippage, etc.), the absolute
encoder position relative to the motor poles is no longer valid and will
require the position to be relearned. If the LE06 Encoder Pole Posi-
tion has changed by more than 2,000 from the previous value, this
indicates a change in physical position relation of the encoder to
the rotor, generally due to encoder slippage over time (potentially
distance or change in direction as well), mounting issues, or me-
chanical aspects.
When the encoder/motor pole position is incorrect, the motor will tend to
draw high current, hitting the LC30 Maximum Torque setting or Inverter
Peak Current Limit, and tending to stall or only move in the direction of
weighting.
Motor Data Incorrect Check the motor data against the nameplate values and perform a LL01
Motor Tune if not previously completed.
For PM motors, ensure the relationship between the motor rated speed,
motor rated frequency and number for motor poles is correct in case of
any nameplate rounding. Refer to the LM02 Motor Speed for further
details.
To Next Page
Loading...
