Rockwell Automation 1336F PLUS II User Manual - Firmware 1.xxx-6.xxx - Manual (Page 14)

2–4 Installation/Wiring
Input Power Conditioning In general, the 1336 PLUS II 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 isola-
tion transformer should be considered are as follows:
1. If the AC source experiences frequent power outages or signifi-
cant voltage transients, users should calculate the VA
max
(see for-
mula below). If the source transformer VA exceeds the calculated
VA
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 trans-
former should be considered.
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 capaci-
tors. If the capacitors are permanently connected and not
switched, the general rules above apply.
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
=