Chapter 1 Introduction; What Is Emc; Emc For Ac Motor Drive - Delta VFD-ED Series User Manual

1.1 What is EMC?

Electromagnetic Compatibility (EMC) is the ability of an electrical device to function properly in
electromagnetic environments. It does not emit electromagnetic noise to surrounding equipment and is
immune to interference from surrounding equipment. The goal is to achieve high immunity and low
emission; these two properties define the quality of EMC. In general, electrical devices react to high and
low frequency phenomena. High frequency phenomena are electrostatic discharge (ESD); pulse
interference; radiated electromagnetic field; and conducted high frequency electrical surge. Low
frequency phenomena refer to mains power harmonics and imbalance.
The standard emission and immunity levels for compliance depend on the installation location of
the drive. A Power Drive System (PDS) is installed in an industrial or domestic environment. A PDS in a
domestic environment must have lower emission levels and is allowed to have lower immunity levels. A
PDS in an industrial environment is allowed to have higher emission levels but must have more severe
immunity levels.

1.2 EMC for AC Motor Drive

When an AC motor drive is put into operation, harmonic signal will occur at the AC drive's power
input and output side. It creates a certain level of electromagnetic interference to the surrounding
electrical devices and the mains power network. An AC motor dive is usually applied in industrial
environments with a strong electromagnetic interference. Under such conditions, an AC drive could
disturb or be disturbed.
Delta's AC motor drives are designed for EMC and comply with EMC standard EN61800-3 2004.
Installing the AC motor drive accurately will decrease EMI influences and ensure long term stability of the
electricity system. It is strongly suggested to follow Delta's user manual for wiring and grounding. If any
difficulties or problems arise, please follow the instructions and measures as indicated in this EMC
Standard Installation Guide.
Appendix A: EMC Standard Installation Guide

Chapter 1 Introduction

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