Calibrating Actual Car Speed - MCi iControl User Manual

Calibrating Actual Car Speed

If iLand and iLink are already installed, use the landing system speed (Speed/Actual on the
Operational Status tab) as the speed reference for speed calibration. If not, use a hand-held
tachometer to obtain the value.
If you are using a hand-held tachometer, hold it against the hoist or governor rope on the
machine. The car must run at the commanded inspection speed in both directions (see Cau-
tion). If the measured inspection speed does not match the commanded value, verify the follow-
ing:
1. Verify the Inspection - High Speed parameter (iView: Configuration > Pattern > Modes
tab or iBox: Car/Pattern Profile/Inspection high velocity).
2. Verify that Pattern scaling is set to 100% (Configuration > Pattern > Common tab).
3. Verify drive parameters set earlier.
4. Adjust motor parameter LF.22 Gear Reduction Ratio in small increments to obtain the
correct Inspection speed (see Note).
Note
Gear Reduction Ratio: If the gear reduction ratio is not available from the machine name plate,
calculate the value by first measuring the motor revolutions using a marker on the motor shaft
or brake drum. Reduce the inspection speed by decreasing the Inspection High speed setting,
then determine the number of motor shaft revolutions required to complete one revolution of
the sheave. Calculate the gear reduction ratio using the formula: Gear reduction ratio = Motor
RPM / Sheave RPM. Enter the calculated value in parameter LF.22.
The drive has the capability of estimating the gear reduction ratio. Run the car on inspection
and read the value of parameter LF.25, the gear ratio estimated by the drive. The value of LF.25
can be temporarily used for LF.22.
Caution
Up vs. down speed variance: If the car runs at commanded speed in one direction but
less then commanded speed in the other direction, this can indicate insufficient voltage
available to generate the required torque. At inspection speed this may be a little as 1 or 2
fpm, but at contract speed this variance will be much greater. On a small percentage of jobs
it is necessary to increase the value of parameter LF.14 Rated Motor Voltage. For example,
for a motor rated for 480 volts it may be necessary to increase LF.14 to 500 volts.
Running on Machine Room Inspection
Please refer to "AC Drive Parameters" on page 2-47.
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