Using Inverters for Elevating Machines
6-
177
Fig 6.86 Torque Compensation Time Chart (Lowering)
Analog Input Filter Time Constant
If noise enters the analog frequency reference during operation using analog frequency reference (b1-01 = 1),
and operation becomes rough, implement noise countermeasures and also set H3-12 (Analog input filter time
constant) to between 0.01 and 0.10 s.
Confirming Startup Current and Reducing Carrier Frequency
When performing trial operation, check the motor current using the Digital Operator or a clamp ammeter with
and without a mechanical load. An extremely high current will flow if the motor torque at start is insufficient,
or if timing is not correct and the motor locks with the holding brake.
If the current at start is more than the Inverter overload level, the IGBT in the Inverter will be subject to heat
stress, resulting in a shortened life span. Refer to the previous precautions and take measures, such as retuning
and reducing the load until the current drops to less than the Inverter overload level. If particularly low noise is
not required, do not increase the Inverter’s carrier frequency to reduce the influence of heat stress.
Overvoltage Inhibit Function (SPEC: E or Later Only)
Leave L3-11 (Overvoltage inhibit function selection) set to 0 (disabled: factory setting). This function is used
to prevent overvoltage tripping when the braking resistor is not used with a regenerative load. When this func-
tion is enabled, the torque reference on the regenerative side is automatically inhibited in the Inverter during
regeneration. Using this function in elevating machines is dangerous because the elevator may slip and fall.
Contact your Yaskawa representative for details on applications such as high-speed elevators (speed: 2 m/s or higher),
direct-drive elevators, or Inverters designed for cranes.
IMPORTANT
1. For either increasing or decreasing torque, externally maintain the torque compensation signals during
operation to prevent them from fluctuating. Fluctuation in compensation signals during operation may result
in vibration.
2. If reverse run is used for lifting and forward run is used for lowering, the torque compensation signal polar-
ity must be reversed.
OFF
OFF
ON
DOWN (Forward)
ON
HIGH/LOW
Output frequency
0
Motor torque
0
OFF
ON
During run 2
OPEN
Holding brake operation
CLOSE
(Regenerative load: Inputs positive polarity.)
(Motor load: Inputs negative polarity.)
t
(Regenerative load)
(Motor load)
Analog signals corresponding to load size
Same as above
Torque compensation
signal: 0
