Technical data

VLT
®
2800 Series
All about VLT
2800
■ Special conditions
■ Aggressive environments
As all other electronic equipment, a frequency
converter contains a number of mechanical and
electronic components, which to a varying extent
are vulnerable to environmental impact.
Consequently, the frequency converter is
not to be installed in environments, where
liquids, particles or gases are in the air that
would impact and damage the electronics. Unless
the necessary measures are taken to protect the
frequency converter, there is a risk of stoppages, which
reduce the service life of the frequency converter.
Liquids can be carried through the air and condense
in the frequency converter. In addition, liquids may
facilitate galvanic corrosion of components and metal
parts. Steam, oil and brine may cause corrosion of
components and metal parts. In these areas, it is
recommended to fit units in cabinets. As a minimum,
cabinets should be enclosure IP 54.
P
articles in the air, such as dust particles, may lead
to mechanical, electrical and thermal faults on the
frequency converter. Typical indicators that there
are too many particles in the air are dust particles
around the frequency converter fan. In very dusty
areas, cabinet fitting of units is recommended. A
sa
minimum, cabinets should be enclosure IP 54.
A
ggressive gases, such as sulphur, nitrogen and
chlorine compounds, together with high humidity and
temperature, facilitate possible chem
ical processes on
the components of the frequency converter. These
chemical processes quickly impact and damage
the electronics. In these areas,
cabinet fitting with
fresh-air circulation in the cabinet is recommended,
thereby ensuring that aggressive gases are kept
away from the frequency conver
ter.
NB!:
Fitting of frequency converters in aggressive
environments increases the risk of stoppages,
in addition to consider
ably reducing
the service life of the unit.
Before the frequency converter is installed, it must
be checked whether there are liquids, particles or
gases in the air. Thi
s can be done by looking at
existing installations in the same environment. Typical
indicators of harmful airborne liquids are water or
oil on metal parts
or corrosion of metal parts. Too
many dust particles are typically observed on top
of installation cabinets and on existing electrical
installations. Indicators that there are aggressive
gases in the air are copper rails and cable ends that
are black on existing electrical installations.
■ Derating for ambient temperature
The ambient temperature (T
AMB,MAX
) is the maximum
temperature allowed. The average (T
AMB,AVG
)
measured over 24 hours, must be at least 5
°C lower. If the frequency converter operates
at temperatures above 45 °C, a derating of the
rated output current is necessary.
■ Derating for high switching frequency - VLT 2800
A higher switching frequency (to be set in parameter
411, Switching frequency) leads to higher losses in
the electronics of the frequency converter.
VLT 2800 has a pulse pattern in which it is possible to
set the switching frequency from 3.0- 10.0/14.0 kHz.
The frequency converter will automatically derate
the rated output current I
VLT,N,
when the switching
frequency exceeds 4.5 kHz.
In both cases, the reduction is carried out
linearly, down to 60% of I
VLT,N
.
MG.28.A9.02 - VLT is a registered Danfoss trademark
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