Hitachi L200 Manual Do Utilizador

Página de 280
Using the Front Panel Keypad
In
v
e
rt
er Mounting
and Installation
2–32
Powerup Test Observations and Summary
Step 10: Reading this section will help you make some useful observations when first 
running the motor.
Error Codes - If the inverter displays an error code (format is “
E X X
”), se
 to interpret and clear the error.
Acceleration and Deceleration - The L200 inverter has programmable acceleration and 
deceleration values. The test procedure left these at the default value, 10 seconds. You 
can observe this by setting the potentiometer at about half speed before running the 
motor. Then press RUN, and the motor will take 5 seconds to reach a steady speed. Press 
the STOP key to see a 5 second deceleration to a stop.
State of Inverter at Stop - If you adjust the motor’s speed to zero, the motor will slow to 
a near stop, and the inverter turns the outputs OFF. The high-performance L200 can 
rotate at a very slow speed with high torque output, but not zero (must use servo systems 
with position feedback for that feature). This characteristic means you must use a 
mechanical brake for some applications.
Interpreting the Display - First, refer to the output frequency display readout. The 
maximum frequency setting (parameter A004) defaults to 50 Hz or 60 Hz (Europe and 
United States, respectively) for your application.
Example: Suppose a 4-pole motor is rated for 60 Hz operation, so the inverter is config-
ured to output 60 Hz at full scale. Use the following formula to calculate the RPM.
The theoretical speed for the motor is 1800 RPM (speed of torque vector rotation). 
However, the motor cannot generate torque unless its shaft turns at a slightly different 
speed. This difference is called slip. So it’s common to see a rated speed of approxi-
mately 1750 RPM on a 60 Hz, 4-pole motor. Using a tachometer to measure shaft speed, 
you can see the difference between the inverter output frequency and the actual motor 
speed. The slip increases slightly as the motor’s load increases. This is why the inverter 
output value is called “frequency,” since it is not exactly equal to motor speed. You can 
program the inverter to display output frequency in units more directly related to the load 
speed by entering a constant (discussed more in depth on page 
).
Run/Stop Versus Monitor/Program Modes – 
The Run LED on the inverter is ON in Run Mode, 
and OFF in Stop Mode. The Program LED is ON 
when the inverter is in Program Mode, and OFF for 
Monitor Mode. All four mode combinations are 
possible. The diagram to the right depicts the 
modes and the mode transitions via keypad.
NOTE: Some factory automation devices such as PLCs have alternate Run/Program 
modes; the device is in either one mode or the other. In the Hitachi inverter, however, 
Run Mode alternates with Stop Mode, and Program Mode alternates with Monitor 
Mode. This arrangement lets you program some values while the inverter is operating—
providing flexibility for maintenance personnel.
10
Speed in RPM
Frequency 60
×
Pairs of poles
----------------------------------------
Frequency 120
×
# of poles
-------------------------------------------
60 120
×
4
---------------------
1800RPM
=
=
=
=
Run
Stop
Monitor
Program
RUN
STOP
RESET
FUNC.