Operation; Precautions For Use Of The Inverter - Mitsubishi Electric FR-A700 Instruction Manual

Operation

4 Operation
4.1

Precautions for use of the inverter

The FR-A700 series is a highly reliable product, but incorrect peripheral circuit making or op-
eration/handling method may shorten the product life or damage the product.
Before starting operation, always recheck the following items.
● Use crimping terminals with insulation sleeve to wire the power supply and motor.
● Application of power to the output terminals (U, V, W) of the inverter will damage the inverter.
Never perform such wiring.
● After wiring, wire offcuts must not be left in the inverter.
Wire offcuts can cause an alarm, failure or malfunction. Always keep the inverter clean.
When drilling mounting holes in a control box etc., take care not to allow chips and other
foreign matter to enter the inverter.
● Use cables of the size to make a voltage drop 2% maximum.
If the wiring distance is long between the inverter and motor, a main circuit cable voltage
drop will cause the motor torque to decrease especially at the output of a low frequency.
(Refer to page 3-12 for the recommended cable sizes.)
● The overall wiring length should be 500m maximum. (The wiring length should be 30m
maximum for vector control.)
Especially for long distance wiring, the fast-response current limit function may be reduced
or the equipment connected to the inverter output side may malfunction or become faulty
under the influence of a charging current due to the stray capacity of the wiring. Therefore,
note the overall wiring length. (Refer to page 3-15.)
● Electromagnetic Compatibility
Operation of the frequency inverter can cause electromagnetic interference in the input and
output that can be propagated by cable (via the power input lines), by wireless radiation to
nearby equipment (e.g. AM radios) or via data and signal lines.
Activate the integrated EMC filter (and an additional optional filter if present) to reduce air
propagated interference on the input side of the inverter. Use AC or DC reactors to reduce
line propagated noise (harmonics). Use shielded motor power lines to reduce output noise
(refer also to section 3.8 Electromagnetic Compatibility).
● Do not install a power factor correction capacitor, surge suppressor or radio noise filter on
the inverter output side. This will cause the inverter to trip or the capacitor and surge
suppressor to be damaged. If any of the above devices is installed, immediately remove it.
● Before starting wiring or other work after the inverter is operated, wait for at least 10 minutes
after the power supply has been switched off, and check that there are no residual voltage
using a tester or the like. The capacitor is charged with high voltage for some time after
power off and it is dangerous.
FR-A700 EC
Precautions for use of the inverter
4 - 1