Mitsubishi Electric FR-D720S SC EC, Instruction Manual

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VI
Emergency stop
Maintenance, inspection and parts replacement
b
CAUTION:
●
The electronic thermal relay function does not guarantee protection of the motor
from overheating. It is recommended to install both an external thermal and PTC
thermistor for overheat protection.
●
Do not use a magnetic contactor on the inverter input for frequent starting/stopping
of the inverter. Otherwise, the life of the inverter decreases.
●
Use a noise filter to reduce the effect of electromagnetic interference and follow
the accepted EMC procedures for proper installation of frequency inverters. Oth-
erwise nearby electronic equipment may be affected.
●
Take appropriate measures regarding harmonics. Otherwise this can endanger
compensation systems or overload generators.
●
Use a motor designed for inverter operation. (The stress for motor windings is
bigger than in line power supply).
●
When parameter clear or all clear is performed, set again the required parameters
before starting operations. Each parameter returns to the initial value.
●
The inverter can be easily set for high-speed operation. Before changing its setting,
fully examine the performances of the motor and machine.
●
The DC braking function of the frequency inverter is not designed to continuously
hold a load. Use an electro-mechanical holding brake on the motor for this purpose.
●
Before running an inverter which had been stored for a long period, always perform
inspection and test operation.
●
For prevention of damage due to static electricity, touch nearby metal before
touching this product to eliminate static electricity from your body.
b
CAUTION:
●
Provide a safety backup such as an emergency brake which will prevent the
machine and equipment from hazardous conditions if the inverter fails.
●
When the breaker on the inverter primary side trips, check for the wiring fault (short
circuit), damage to internal parts of the inverter, etc. Identify the cause of the trip,
then remove the cause and power on the breaker.
●
When the protective function is activated (i. e. the frequency inverter switches off
with an error message), take the corresponding corrective action as described in
the inverter manual, then reset the inverter, and resume operation.
b
CAUTION:
●
Do not carry out a megger (insulation resistance) test on the control circuit of the
inverter. It will cause a failure.