Rockwell Automation FlexPak 3000 DC Drive Version 4.3 - Manual (Page 22)

2-8 FlexPak 3000 DC Drive Hardware Reference Version 4.3
2.2 Install a Transformer
Input transformers step up or step down input voltage and can be either auto or
isolation transformer types. Users should consider using an isolation transformer
instead of an auto transformer for the following advantages:
• AC power line disturbances and transients are minimized by an isolation
transformer, thus reducing or eliminating possible damage to solid state
components.
• An isolation transformer provides electrical isolation for the drive from plant power
system grounds. Damaging currents may be avoided in instances where the DC
output is accidentally grounded or where the DC motor circuits are grounded.
Refer to tables A.1 and A.6 for more information. Reliance offers a series of isolation
transformers suitable for use with the drive. Call you local Reliance Electric sales
office for assistance.
2.3 Install an Input Disconnect
Any fused disconnect or circuit breaker in the incoming AC line must accommodate a
maximum symmetrical AC fault current as indicated in Appendix A of this instruction
manual. Size the disconnect to handle the transformer primary current as well as any
additional loads the disconnect may supply.
Step 1. Install an input disconnect in the incoming power line according to the NEC/
CEC if not provided with the drive. The disconnect switch should be within
clear view of machine operator and maintenance personnel for easy access
and safety. An open-type switch with provisions for a padlock is
recommended.
Step 2. Wire this disconnect in the primary circuit of the drive isolation transformer (if
used).
!
ATTENTION:If an input transformer is installed ahead of the drive, a
power disconnecting device must be installed between the power line
and the primary of the transformer. If this power disconnecting device is
a circuit breaker, the circuit breaker trip rating must be coordinated with
the inrush current (10 to 12 times full-load current) of the input
transformer. Distribution system capacity above the maximum
recommended system KVA requires using an isolation transformer, a line
reactor, or other means of adding similar impedance. Failure to observe
this precaution could result in damage to, or destruction of, the equipment
ATTENTION: Connection of a drive to a transformer with a primary rating
of 2300 VAC or more may require additional input line conditioning.
Contact your local Reliance Electric sales/service office for assistance
when this is required. Failure to observe this precaution could result in
damage to, or destruction of, the equipment.
!
ATTENTION:The NEC/CEC requires that an input disconnect be
provided in the incoming power line and either be located within sight of
the drive or have provisions for a padlock. Install an input disconnect in
the incoming power line that is located within sight of the drive or that
has provisions for a padlock. Failure to observe this precaution could
result in severe bodily injury or loss of life.