Precautions For Use Of The Inverter - Mitsubishi Electric FR-A760-00017-NA Installation Manuallines

PRECAUTIONS FOR USE OF THE
INVERTER

4 PRECAUTIONS FOR USE OF THE INVERTER

The FR-A700 series 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 items.
(1) Use crimping terminals with insulation sleeve to wire the p
(2) Application of power to the output terminals (U, V, W) of the inverter will damage the inverter. Never perform such
wiring.
(3) 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 an enclosure etc., take care not to allow chips and other foreign matter to enter the inverter.
(4) 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 8 for the recommended cable sizes.
(5) The overall wiring length should be 500m (1640.4 feet) maximum.
(The wiring length should be 100m (328.1 feet) maximum for vector control.)
Especially for long distance wiring, the fast-response current limit function may decrease or the equipment
connected to the secondary 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 9.)
(6) Electromagnetic wave interference
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.
(7) 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.
(8) 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.
(9) A short circuit or earth (ground) fault on the inverter output side may damage the inverter modules.
· 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 modules.
· Fully check the to-earth (ground) insulation and inter-phase insulation of the inverter output side before power-
on.
Especially for an old motor or use in hostile atmosphere, securely check the motor insulation resistance etc.
(10) Do not use the inverter input side magnetic contactor to start/stop the inverter.
Always use the start signal (ON/OFF of STF and STR signals) to start/stop the inverter.
(11) Across P/+ and PR terminals, connect only an external regenerative brake discharge resistor.
Do not connect a mechanical brake.
(12) Do not apply a voltage higher than the permissible voltage to the inverter I/O signal circuits.
Contact 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 terminals 10E-5.
11
ower supply and motor.