Noise Prevention - Fuji Electric FRENIC-HVAC User Manual

(3) Radiation noise
Noise generated in an inverter may be radiated through the air from wires (that act as
antennas) at the input and output sides of the inverter so as to affect peripheral devices.
This noise is called "radiation noise"
frames or control system panels containing inverters may also act as antennas.
A.3

Noise prevention

The more noise prevention is strengthened, the more effective. However, with the use of
appropriate measures, noise problems may be resolved easily. It is necessary to
implement economical noise prevention according to the noise level and the equipment
conditions.
[ 1 ] Noise prevention prior to installation
Before installing an inverter in your control panel or installing an inverter panel, you
need to consider noise prevention. Once noise problems occur, it will cost additional
materials and time for solving them.
Noise prevention prior to installation includes:
1) Separating the wiring of main circuits and control circuits
2) Putting main circuit wiring into a metal conduit pipe
3) Using shielded wires or twisted shielded wires for control circuits.
4) Implementing appropriate grounding work and grounding wiring.
These noise prevention measures can avoid most noise problems.
App. A Advantageous Use of Inverters (Notes on electrical noise)
Figure A.5 Electrostatic Induced Noise
as shown below. Not only wires but motor
Figure A.6 Radiation Noise
A-5