Rockwell Automation 1336S Plus FRN 1.xx-5.xx - Manual (Page 14)

2–4 Installation/Wiring
In general, the 1336 PLUS 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 AC source experiences frequent power outages or
significant voltage transients, users should calculate the kVA
max
(see formula below). If the source transformer kVA exceeds the
calculated kVA
max
and the drive is installed close to the source, it
is an indication that there may be enough energy behind these
voltage transients to cause nuisance input fuse blowing,
overvoltage faults or drive power structure damage. In these
cases, a line reactor or isolation transformer should be considered.
Z
drive
(
Ω/Φ
) =
V
line–line
√
3 x Input Amps
(V
line–line
) 2 x % Source Leakage (5-6% typical)
Z
drive
x 0.01
VA
max
=
2. If the AC source does not have a neutral or one phase referenced
to ground (see Unbalanced Distribution Systems on page 2–3),
an isolation transformer with the neutral of the secondary
grounded is highly recommended. If the line-to-ground voltages
on any phase can exceed 125% of the nominal line-to-line
voltage, an isolation transformer with the neutral of the secondary
grounded, is highly recommended.
3. If the AC line supplying the drive has power factor correction
capacitors that are switched in and out, an isolation transformer or
5% line reactor is recommended between the drive and
capacitors. If the capacitors are permanently connected and not
switched, the general rules above apply.
Input Power Conditioning