Input power conditioning, General grounding requirements – Rockwell Automation 25B PowerFlex 520-Series Adjustable Frequency AC Drive User Manual User Manual
Page 20
20
Rockwell Automation Publication 520-UM001G-EN-E - September 2014
Chapter 1
Installation/Wiring
Input Power Conditioning
The drive is suitable for direct connection to input power within the rated
voltage of the drive (see
). Listed in the
table
below are certain input power conditions which may cause component damage or
reduction in product life. If any of these conditions exist, install one of the devices
listed under the heading Corrective Action on the line side of the drive.
General Grounding
Requirements
The drive Safety Ground -
(PE) must be connected to system ground. Ground
impedance must conform to the requirements of national and local industrial
safety regulations and/or electrical codes. The integrity of all ground connections
should be periodically checked.
Typical Grounding
IMPORTANT
Only one device per branch circuit is required. It should be mounted closest to
the branch and sized to handle the total current of the branch circuit.
Input Power Conditions
Input Power Condition
Corrective Action
Low Line Impedance (less than 1% line reactance)
• Install Line Reactor
(2)
• or Isolation Transformer
(2) See
for accessory ordering information.
Greater than 120 kVA supply transformer
Line has power factor correction capacitors
• Install Line Reactor
(2)
• or Isolation Transformer
Line has frequent power interruptions
Line has intermittent noise spikes in excess of 6000V (lightning)
Phase to ground voltage exceeds 125% of normal line to line voltage
• Remove MOV jumper to ground.
• or Install Isolation Transformer with
grounded secondary if necessary.
Ungrounded distribution system
240V open delta configuration (stinger leg)
(1)
(1) For drives applied on an open delta with a middle phase grounded neutral system, the phase opposite the phase that is tapped in
the middle to the neutral or earth is referred to as the “stinger leg,” “high leg,” “red leg,” etc. This leg should be identified throughout
the system with red or orange tape on the wire at each connection point. The stinger leg should be connected to the center Phase B
on the reactor. See
Bulletin 1321-3R Series Line Reactors on page 171
for specific line reactor part numbers.
• Install Line Reactor
(2)
SHLD
U/T1
V/T2
W/T3
R/L1
S/L2
T/L3
Esc
Sel