Frequently Asked Questions - Hitachi WJ200-001S Instruction Manual

Frequently Asked Questions

Q. Q. What is the main advantage in using an inverter to drive a motor, compared to Q. Q.
alternative solutions?
A. A. A. A. An inverter can vary the motor speed with very little loss of efficiency, unlike
mechanical or hydraulic speed control solutions. The resulting energy savings
usually pays for the inverter in a relatively short time.
Q. The term "inverter" is a little confusing, since we also use "drive" and "amplifier" to Q. Q. Q.
describe the electronic unit that controls a motor. What does "inverter" mean?
A. A. A. A. The term
industry. Nowadays, the term
drive
,
microprocessor-based motor speed controllers. In the past,
drive
term almost exclusively used to describe drives for servo or stepper motors.
Q. Although the WJ200 inverter is a variable speed drive, can I use it in a fixed-speed Q. Q. Q.
application?
A. A. A. A. Yes, sometimes an inverter can be used simply as a "soft-start" device,
providing controlled acceleration and deceleration to a fixed speed. Other
functions of the WJ200 may be useful in such applications, as well. However,
using a variable speed drive can benefit many types of industrial and
commercial motor applications, by providing controlled acceleration and
deceleration, high torque at low speeds, and energy savings over alternative
solutions.
Q. Can I use an inverter and AC induction motor in a positioning application? Q. Q. Q.
A. A. A. A. That depends on the required precision, and the slowest speed the motor must
turn and still deliver torque. The WJ200 inverter will deliver full torque while
turning the motor at 6Hz (180RPM). DO NOT use an inverter if you need the
motor to stop and hold the load position without the aid of a mechanical brake
(use a servo or stepper motion control system).
Q. Can the inverter be controlled and monitored via a network? Q. Q. Q.
A. A. A. A. Yes. WJ200 inverters have built-in ModBus communications. See Appendix B
for more information on network communications.
Q. Why does the manual or other documentation use terminology such as "200V class" Q. Q. Q.
instead of naming the actual voltage, such as "230 VAC"
A. A. A. A. A specific inverter model is set at the factory to work across a voltage range
particular to the destination country for that model. The model specifications
are on the label on the side of the inverter. A European 200V class inverter
("EU" marking) has different parameter settings than a USA 200V class.
N N N N OTE OTE: The European 200V class inverter is for single phase input (-SFE), while the
OTE OTE
USA 200V class inverter is for 3 phase input (-LFU).
inverter, drive,
and
inverter
and are
also referred to various mechanical means to vary speed.
amplifier
are used somewhat interchangeably in
drive variable-frequency drive
,
generally used
variable-speed
,
to describe electronic,
variable-speed
Amplifier
1− − − − 23
is a