Danfoss VLT FC 102 Series Design Manual page 49

Introduction to VLT® HVAC D...
To reduce the interference level from the entire system
(unit+installation), make motor and brake cables as short
as possible. Avoid placing cables with a sensitive signal
level alongside motor and brake cables. Radio interference
higher than 50 MHz (airborne) is especially generated by
the control electronics. See for more information on EMC.
2.9.1 Emission Requirements
According to the EMC product standard for adjustable
speed adjustable frequency drives EN/IEC 61800-3:2004,
the EMC requirements depend on the intended use of the
adjustable frequency drive. Four categories are defined in
the EMC product standard. The definitions of the four
categories together with the requirements for line power
supply voltage conducted emissions are given in
Table 2.17.
Category Definition
C1 Adjustable frequency drives
installed in the first environment
(home and office) with a supply
voltage less than 1000 V.
C2 Adjustable frequency drives
installed in the first environment
(home and office) with a supply
voltage less than 1000 V, which are
neither plug-in nor movable and
are intended to be installed and
commissioned by a professional.
C3 Adjustable frequency drives
installed in the second environment
(industrial) with a supply voltage
lower than 1000 V.
C4 Adjustable frequency drives
installed in the second environment
with a supply voltage equal to or
above 1000 V or rated current
equal to or above 400 A or
intended for use in complex
systems.
Table 2.17 Emission Requirements
MG11BC22
Design Guide
When the generic (conducted) emission standards are used
the adjustable frequency drives are required to comply
with the following limits.
Environment
First
environment
(home and
office)
Second
environment
(industrial
environment)
Conducted
Table 2.18 Limits at Generic Emission Standards
emission
requirement
2.9.2 EMC Test Results
according to
the limits
The following test results have been obtained using a
given in EN
system with an adjustable frequency drive, a shielded
55011
control cable, a control box with potentiometer, as well as
Class B
a motor and shielded motor cable at nominal switching
frequency. In Table 2.19, the maximum motor cable lengths
for compliance are stated.
Class A Group 1
Class A Group 2
No limit line.
An EMC plan
should be
made.
Danfoss A/S © Rev. 06/2014 All rights reserved.
Conducted
emission
requirement
Generic standard
according to the
limits given in
EN 55011
EN/IEC 61000-6-3 Emission Class B
standard for residential,
commercial and light
industrial environments.
EN/IEC 61000-6-4 Emission Class A Group 1
standard for industrial
environments.
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