Chapter 5 Troubleshooting
VFD-EL-W
5-11
5.12 Electromagnetic/Induction Noise
Many sources of noise surround AC motor drives and affect them by radiation or conduction. This may cause
the control circuits to malfunction and even damage the AC motor drive. Of course, there are solutions to
increase the noise tolerance of an AC motor drive, but this has its limits. Solving the problem from the outside
as follows is the best.
1. Add a surge suppressor on the relays and contacts to suppress switching surges.
2. Shorten the length of the wiring for the control circuit or serial communication and keep them separated
from the power circuit wiring.
3. Comply with the wiring regulations by using shielded wires and isolation amplifiers for long wire length.
4. The grounding terminal must comply with the local regulations and be grounded independently; that is,
do not use a common ground with electric welding machines and other power equipment.
5. Connect a noise filter at the mains input terminal of the AC motor drive to filter noise from the power
circuit.
In short, solutions for electromagnetic noise exist of “no product” (disconnect disturbing equipment), “no
spread” (limit emission from disturbing equipment) and “no receive” (enhance immunity).
5.13 Operating Environment Condition
Since the AC motor drive is an electronic device, you must deal with the operating environment conditions.
Here are some remedial measures to use if necessary.
1. To prevent vibration, anti-vibration dampers are the last choice. Vibration must be within the
specification. Vibration causes mechanical stress and it should not occur frequently, continuously or
repeatedly to prevent damage to the AC motor drive.
2. Store the AC motor drive in a clean and dry location, free from corrosive fumes/dust to prevent corrosion
and poor contacts. Poor insulation in a humid location can cause short circuits. If necessary, install the
AC motor drive in a dust-proof and painted enclosure. If necessary in particular situations, use a
completely sealed enclosure.
3. The ambient temperature should be within the specification. Too high or too low temperature affects the
lifetime and reliability of the AC motor drive. For semiconductor components, damage occurs once any
specification is out of range. It is necessary to periodically check air quality and the cooling fan and
provide extra cooling if required. In addition, the microcomputer may not work in extremely low
temperatures, making cabinet heating necessary.
4. Store the AC motor drive in a relative humidity range of 0% to 90% (non-condensing). Use an air
conditioner and/or desiccator if necessary.
To Next Page
Loading...
Need help?
General