Checklist Before Starting Operation - Mitsubishi Electric FR-F862-E Instruction Manual

Checklist before starting operation

3.6
Checklist before starting operation
The FR-F860 series inverter and FR-CC2-C converter unit are highly reliable products, but incorrect peripheral circuit making
or operation/handling method may shorten the product life or damage the products.
Before starting operation, always recheck the following points.
Point to be checked
Crimp terminals are insulated.
The wiring between the power
supply (R/L1, S/L2, T/L3) and the
motor (U, V, W) is correct.
No wire offcuts are left from the time
of wiring.
The main circuit cable gauge is
correctly selected.
The total wiring length is within the
specified length.
Precautions are taken against EMI.
Countermeasures are taken against
electrical corrosion on the motor
bearing.
On the inverter's output side, there
is no power factor correction
capacitor, surge suppressor, or
radio noise filter installed.
When performing an inspection or
rewiring on the product that has
been energized, the operator has
waited long enough after shutting off
the power supply.
The inverter's output side has no
short circuit or ground fault
occurring.
The circuit is not configured to use
the converter unit's input-side
magnetic contactor to start/stop the
inverter frequently.
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PRECAUTIONS FOR USE OF THE INVERTER
Use crimp terminals with insulation sleeves to wire the power supply and the
motor.
Application of power to the output terminals (U, V, W) of the inverter will
damage the inverter. Never perform such wiring.
Wire offcuts can cause an alarm, failure or malfunction. Always keep the
inverter and the converter unit clean.
When drilling mounting holes in an enclosure etc., take caution not to allow
chips and other foreign matter to enter the inverter and the converter unit.
Use an appropriate cable gauge to suppress the voltage drop to 2% or less.
If the wiring distance is long between the inverter and motor, the voltage drop
in the main circuit will cause the motor torque to decrease especially during the
output of a low frequency.
Keep the total wiring length is within the specified length.
In long distance wiring, charging currents due to stray capacitance in the wiring
may degrade the fast-response current limit operation or cause the equipment
on the inverter's output side to malfunction. Pay attention to the total wiring
length.
The input/output (main circuit) of the inverter and the converter unit includes
high frequency components, which may interfere with the communication
devices (such as AM radios) used near the inverter and the converter unit. In
such case, enable the built-in EMC filter of the converter unit (connect two of
the EMC filter ON/OFF female connectors to the ON male connectors) to
minimize interference.
When a motor is driven by the inverter, axial voltage is generated on the motor
shaft, which may cause electrical corrosion of the bearing in rare cases
depending on the wiring, load, operating conditions of the motor or a specific
inverter setting (high carrier frequency).
Contact your sales representative to take appropriate countermeasures for the
motor.
The following shows examples of countermeasures for the inverter.
• Decrease the carrier frequency.
• Provide a common mode choke on the output side of the inverter.

Recommended common mode choke: FT-3KM F series FINEMET
common mode choke cores manufactured by Hitachi Metals, Ltd.
FINEMET is a registered trademark of Hitachi Metals, Ltd.
Doing so will cause the inverter to trip or the capacitor and surge suppressor to
be damaged. If any of the above devices is connected, immediately remove it.
For a short time after the power-OFF, a high voltage remains in the smoothing
capacitor, and it is dangerous.
Before performing an inspection or rewiring, wait 10 minutes or longer after the
power supply turns OFF, then confirm that the voltage across the main circuit
terminals P/+ and N/- of the inverter is low enough using a tester, etc.
• A short circuit or earth (ground) fault on the inverter's output side may
damage the inverter module.
• Fully check the insulation resistance of the circuit prior to inverter operation
since repeated short circuits caused by peripheral circuit inadequacy or an
earth (ground) fault caused by wiring inadequacy or reduced motor insulation
resistance may damage the inverter module.
• Fully check the to-earth (ground) insulation and phase-to-phase insulation of
the inverter's output side before power-ON. Especially for an old motor or use
in hostile atmosphere, securely check the motor insulation resistance, etc.
Since repeated inrush currents at power ON will shorten the life of the inverter
and the converter unit, frequent starts and stops of the magnetic contactor
must be avoided. Turn ON/OFF the inverter's start signals (STF, STR) to run/
stop the inverter.
Action
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