Omron VARISPEED E7 User Manual page 59

Wiring the Output Side of Main Circuit
Observe the following precautions when wiring the main output circuits.
Connecting the Inverter and Motor
Connect output terminals U/T1, V/T2, and W/T3 respective to the motor lead wires U, V, and W.
Check that the motor rotates forward with the forward run command. Switch over any two of the output termi-
nals to each other and reconnect if the motor rotates in reverse with the forward run command.
Never Connect a Power Supply to Output Terminals
Never connect a power supply to output terminals U/T1, V/T2, and W/T3. If voltage is applied to the output
terminals, the internal circuits of the Inverter will be damaged.
Never Short or Ground Output Terminals
If the output terminals are touched with bare hands or the output wires come into contact with the Inverter cas-
ing, an electric shock or grounding may occur. This is extremely hazardous. Do not short the output wires.
Do Not Use a Phase Advancing Capacitor
Never connect a phase advancing capacitor to an output circuit. The high-frequency components of the
Inverter output may overheat and be damaged and may cause other parts to burn.
Using a Magnetic Contactor
Check the control sequence to make sure, that the magnetic contactor (MC) between the Inverter and motor is
not turned ON or OFF during inverter operation. If the MC is turned ON while the Inverter is operating, a
large inrush current will be created and the inverter's overcurrent protection may operate. If the MC is turned
OFF while the Inverter is operating a large induced voltage may occur and damage the inverter output parts.
Installing a Thermal Overload Relay Contact for Motor Protection
This Inverter has an electronic thermal protection function to protect the motor from overheating. If, however,
more than one motor is operated with one Inverter or a multi-polar motor is used, always install a thermal
relay (THR) between the Inverter and the motor and set L1-01 to 0 (no motor protection). The control circuit
should be designed so that the contacts of the thermal overload relay turn OFF the magnetic contactor on the
main circuit inputs.
Cable Length between Inverter and Motor
If the cable between the Inverter and the motor is long, the high-frequency leakage current will increase, caus-
ing the Inverter output current to increase as well. This may affect peripheral devices. To prevent this, adjust
the carrier frequency (set in C6-02) as shown in
Cable length
Carrier frequency
2-22
Table 2.11. (For details, refer to
Table 2.11 Cable Length between Inverter and Motor
50 m max.
15 kHz max.
Chapter 5, User
100 m max. More than 100 m
10 kHz max.
Parameters.)
5 kHz max.