Allen-Bradley PowerFlex

Input Power Conditioning 2-91
Input Power
Conditioning
In general, the drive is suitable for direct connection to an AC line of the
correct voltage. Certain conditions can exist, however, that prompt
consideration of a line reactor or isolation transformer ahead of the drive.
The basic rules to aid in determining whether a line reactor or isolation
transformer should be considered are as follows:
1. If the source is greater than 6 times the drive kVA then use a reactor or
transformer.
2. If the AC source for the drive does not have a ground reference (neutral
or phase ground), an isolation transformer with the neutral of the
secondary grounded is highly recommended. These products contain PE
referenced capacitors for EMC compliance and PE referenced MOV
devices for input transient voltage limiting. If the drive must be operated
on an ungrounded voltage source, these devices should be disconnected
from PE by removing the appropriate jumpers (Refer to Disconnecting
MOVs and Common Mode Capacitors in the User Manual). Transients
occurring on a non-ground referenced voltage source may generate
excessive line to ground voltages which could exceed the limits of the
insulation system of the drive. Under these conditions, it is highly
recommended that a system level transient voltage suppression device be
employed in order to limit the potential line to ground voltage.
Figure 2.13 Phase to Ground MOV Removal (PF70)
3. Power factor capacitor switching will cause line voltage transients.
Characteristics of how the capacitors are switched and the impedance of
the distribution system will determine the nature of the voltage
transients. If the transients are severe enough and the source impedance
as seen by the drive is low enough, nuisance fuse blowing, overvoltage
faults or drive power structure damage may occur. Historically if there
have been voltage transient issues at the facility where the drive is being
applied, the use of a 5% 3 phase reactor or appropriately sized isolation
transformer for the drive 3 phase power is recommended.
Jog Refer to Jog on page 2-51.
Language PowerFlex drives are capable of communicating in 7 languages; English,
Spanish, German, Italian, French, Portuguese and Dutch. All drive
functions and information displayed on an LCD HIM are shown in the
R
S
T
1234
Three-Phase
AC Input
JP2 JP3