Checklist Before Starting Operation - Mitsubishi Electric FR-A806 Instruction Manual

Checklist before starting operation

3.6
Checklist before starting operation
The FR-A800 series inverter is a highly reliable product, but incorrect peripheral circuit making or operation/handling method
may shorten the product life or damage the product.
Before starting operation, always recheck the following points.
Checkpoint
Crimping 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.
Countermeasures are taken against
EMI.
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
inverter's input-side magnetic contactor
to start/stop the inverter frequently.
The voltage applied to the inverter I/O
signal circuits is within the
specifications.
When using the electronic bypass
operation, electrical and mechanical
interlocks are provided between the
electronic bypass contactors MC1 and
MC2.
88
PRECAUTIONS FOR USE OF THE INVERTER
Countermeasure
Use crimping 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 clean.
When drilling mounting holes in a wall etc., take caution not to allow chips and
other foreign matters to enter the inverter.
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 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 includes high frequency
components, which may interfere with the communication devices (such as
AM radios) used near the inverter. In such case, activate the EMC filter (turn
ON the EMC filter ON/OFF connector) to minimize interference.
Such installation 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 some 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 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 a
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, make sure to check the motor insulation resistance, etc.
Since repeated inrush currents at power ON will shorten the life of the converter
circuit, 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.
Application of a voltage higher than the permissible voltage to the inverter I/O
signal circuits or opposite polarity may damage the I/O devices. Especially
check the wiring to prevent the speed setting potentiometer from being
connected incorrectly to short circuit the terminals 10E and 5.
When using a switching circuit as shown below, chattering due to mis-configured
sequence or arc generated at switching may allow undesirable current to flow in
and damage the inverter. Mis-wiring may also damage the inverter.
(The commercial power supply operation is not available with vector control
dedicated motors (SF-V5RU, SF-THY) nor with PM motors.)
Power
R/L1
supply
S/L2
T/L3
Inverter
If switching to the commercial power supply operation while a failure such as
an output short circuit has occurred between the magnetic contactor MC2 and
the motor, the damage may further spread. If a failure has occurred between
the MC2 and the motor, a protection circuit such as using the OH signal input
must be provided.
MC1
Interlock
U
IM
V
MC2
W
Undesirable current
Refer Check
to by
page user
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