Mitsubishi Electric Freqrol-A100 Instruction Manual page 179

6.1 PRECAUTIONS FOR SELECTING PERIPHERAL DEVICE
Trouble caused by noise and leakages are increasing due to the diffusion of\
electronic devices. Due to its operation principle, the inverter generates noise,
and may adversely affect neighboring devices. The following types of meas-
ures can be taken depending on the installation place, so refer to these when
making your selection.
.
6.1.1 Measures Against Noises
Some noises enter the inverter to misoperate it and others are radiated by the inverter to misoperate
peripheral devices. Though the inverter is designed to be insusceptible to noises, it handles low-level
signals, so it requires the following basic measures to be taken. Also, since the inverter chops output
at high carrier frequency, it could generate noises. If these noises cause peripheral devices to
misoperate, measures should be taken to suppress noises. The measures differ slightly depending
on noise propagation paths.
1) Basic measures
Do not run the power cables (I10 cables) and signal cables of the inverter in parallel with each
other and do not bundle them.
Use twisted shield cables for the detector connecting and control signal cables and connect the
sheathes of the shield cables to terminal SD.
Ground the inverter, motor, etc. at one point.
2) Measures against noises which enter and misoperate the inverter
When devices which generate many noises (which use magnetic contactors, magnetic brakes,
many relays, for example) are installed near the inverter and the inverter may be misoperated by
noises, the following measures must be taken:
Provide surge suppressors for devices that generate many noises to suppress noises.
Fit data line filters to signal cables.
Ground the shields of the detector connection and control signal cables with cable clamp metal.
3)
Measures against noises which are radiated by the inverter to misoperate peripheral devices
Inverter-generated noises are largely classified into those radiated by the cables connected to the
inverter and inverter main circuit (IIO), those electromagnetically and electrostatically inducted to
the signal cables of the peripheral devices close to the main circuit power supply, and those
transmitted through the power supply cables.
- I
noises
I
.......
Static induction
Path
6)
I
ground cable due
.......
Path 8)
to leakage current
.......
Path 4),
5)
Noises directly radi-
ated by inverter
Noises radiated by
power cables
Noises radiated by
motor cables
Noises propagated
through power ca-
bles
'''''''Path ')
.......Path 2)
.......Path 3)
.......
Path 7)