Does The Motor Need A Chassis Ground Connection?; What Type Of Motor Is Compatible With The Hitachi Inverters?; How Many Poles Should The Motor Have? - Hitachi L200 Series Instruction Manual

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Frequently Asked Questions
Q. Why doesn't the motor have a neutral connection as a return to the inverter?
A.
Q.

Does the motor need a chassis ground connection?

A.
Q.

What type of motor is compatible with the Hitachi inverters?

A.
NOTE: There may be other factors that will affect motor selection, including heat dissi-
pation, motor operating speed profile, enclosure type, and cooling method.
Q.

How many poles should the motor have?

A.
Q. Will I be able to add dynamic (resistive) braking to my Hitachi L200 drive after the
initial installation?
A.
The motor theoretically represents a "balanced Y" load if all three stator
windings have the same impedance. The Y connection allows each of the
three wires to alternately serve as input or return on alternate half-cycles.
Yes, for several reasons. Most importantly, this provides protection in the
event of a short in the motor that puts a hazardous voltage on its housing.
Secondly, motors exhibit leakage currents that increase with aging. Lastly, a
grounded chassis generally emits less electrical noise than an ungrounded
one.
Motor type – It must be a three-phase AC induction motor. Use an inverter-
grade motor that has 800V insulation for 200V class inverters, or 1600V
insulation for 400V class.
Motor size – In practice, it's better to find the right size motor for your
application; then look for the inverter to match the motor.
Hitachi inverters can be configured to operate motors with 2, 4, 6, or 8 poles.
The greater the number of poles, the slower the top motor speed will be, but
it will have higher torque at the base speed.
Yes. The L200 inverter already has a dynamic braking circuit built in. Just
add the resistor sized to meet the braking requirements. For more informa-
tion, contact your nearest Hitachi representative.