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Rockwell Automation Publication 6000-UM002G-EN-P - August 2022
Chapter 1 Introduction
See national and local safety guidelines for detailed procedures on how to
isolate the equipment from hazards safely.
Environmental Conditions
•
Elevation above sea level must be less than 1000 m (3250 ft)
(1)
.
•
Ambient air temperature must be between 0...40 °C (32...104 °F)
(2)
.
•
Relative humidity must be less than 95%, noncondensing.
•
Operation Vibration limited to 3M3(a) per IEC60721-3-3.
•
G2 rating with 60% humidity – Storage, Transport, and Operation – as
per ISA 71.04-2013.
•
The drive must be installed indoors; there must be no dripping water or
other fluids in the room.
•
Cooling air must be clean without significant concentrations of sand,
corrosive or conductive dust, or explosive gas. The drive must be installed
in a Pollution Degree 2 environment as per IEC 61800-5.
•
Free from significant vibration.
•
The drive must be anchored on a level floor. Please refer to the dimension
drawing for the anchor point sizes and locations.
For the equipment to operate in conditions other than those specified, consult
the local Rockwell Automation Sales Office.
How it Works
Cascaded “H” Bridge (CHB) Topology
The proven CHB topology combines an integrally mounted phase shifting
isolation transformer and series-connected power modules for each phase. In
addition to stepping down the input voltage, the isolation transformer also
provides two other principal functions:
•
Mitigate common mode voltage stress so motors with standard
insulation levels can be used.
•
Reduce Total Harmonic Distortion (THD), due to the phase shifting of its
secondary windings, so input side harmonics don’t negatively impact the
plant or utility power grid.
A number of identical low voltage power modules are series-connected
(cascaded) together to produce the medium voltage levels that are required to
operate the motor.
The voltage step for each module is relatively small and a Pulse Width
Modulation (PWM) switching pattern is used so output harmonics and torque
pulsations at the motor are minimal, even at lower speeds. This technology is
very motor friendly so standard motors can be used for new applications and it
also is ideal for retrofitting existing motors. This also allows for the motor
cable lengths that are required for most applications, without the requirement
for output filtering.
ATTENTION:
The national and local electrical codes outline provisions for
safely installing and working on electrical equipment. Installation must
comply with specifications regarding wire type, conductor sizes, branch
circuit protection, and disconnect devices. Failure to do so may result in
personal injury and/or equipment damage.
(1) Options are available for operation up to 5000 m.a.s.l. However, these must be stated at the time of order and cannot be retrofitted in the
field.
(2) Options are available for ambient temperatures up to 50 °C. However, these must be stated at the time of order and cannot be retrofitted in
the field.
