Hitachi L200 Manual Do Utilizador

Glossary

Appendix A

The air temperature in the chamber containing a powered electronic 
unit. A unit’s heat sinks rely on a lower ambient temperature in 
order to dissipate heat away from sensitive electronics.

The arrival frequency refers to the set output frequency of the 
inverter for the constant speed setting. The arrival frequency feature 
turns on an output when the inverter reaches the set constant speed. 
The inverter has various arrival frequencies and pulsed or latched 
logic options.

The ability of a controller to execute a procedure that interacts with 
a load to determine the proper coefficients to use in the control 
algorithm. Auto-tuning is a common feature of process controllers 
with PID loops. Hitachi inverters feature auto tuning to determine 
motor parameters for optimal commutation. Auto-tuning is avail-
able as a special command from a digital operator panel. See also 
Digital Operator Panel.

The power input frequency for which an AC induction motor is 
designed to operate. Most motors will specify a 50 to 60 Hz value. 
The Hitachi inverters have a programmable base frequency, so you 
must ensure that parameter matches the attached motor. The term 
base frequency helps differentiate it from the carrier frequency. See 
also Carrier Frequency and Frequency Setting.

An energy-absorbing resistor that dissipates energy from a deceler-
ating load. Load inertia causes the motor to act as a generator 
during deceleration. For the L200 inverter models, the braking unit 
and braking resistor are optional (external) components. See also 
Four-quadrant Operation and Dynamic Braking.

The torque a motor must produce to overcome the static friction of a 
load, in order to start the load moving.

The frequency of the constant, periodic, switching waveform that 
the inverter modulates to generate the AC output to the motor. See 
also PWM.

A regulatory agency for governing the performance of electronic 
products in Europe. Drive installations designed to have CE 
approval must have particular filter(s) installed in the application.

An inductor that is tuned to react at radio frequencies is called a 
“choke,” since it attenuates (chokes) frequencies above a particular 
threshold. Tuning is often accomplished by using a movable 
magnetic core. In variable-frequency drive systems, a choke 
positioned around high-current wiring can help attenuate harmful 
harmonics and protect equipment. See also Harmonics.