Omron SYSDRIVE 3G3MV SERIES User Manual page 59

Design
D Installing a Thermal Relay
The Inverter has an electronic thermal protection function to protect the motor from overheating. If, how-
ever, 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 n037 to 2 (no thermal protection).
In this case, program the sequence so that the magnetic contactor on the input side of the main circuit is
turned OFF by the contact of the thermal relay.
D Installing a Noise Filter on the Output Side
Connect a Noise Filter to the output side of the Inverter to reduce radio noise and induction noise.
Power
supply
Induction Noise:
Radio Noise:
D Countermeasures against Induction Noise
As described previously, a Noise Filter can be used to prevent induction noise from being generated on
the output side. Alternatively, cables can be routed through a grounded metal pipe to prevent induction
noise. Keeping the metal pipe at least 30 cm away from the signal line considerably reduces induction
noise.
Power supply
3G3MV
SYSDRIVE
Signal line
Electromagnetic induction generates noise on the signal line, causing the con-
troller to malfunction.
Electromagnetic waves from the Inverter and cables cause the broadcasting
radio receiver to make noise.
3G3MV
SYSDRIVE
Signal line
3G3IV-PLF
Noise
Filter
Induction noise
AM radio
Controller
Metal pipe
Controller
Chapter 2
Radio noise
30 cm min.
2-27