Rockwell Automation 20D PowerFlex 700H and 700S Frame 9...14 Drives - Manual (Page 25)

Rockwell Automation Publication PFLEX-IN006E-EN-P - July 2013 25
General Installation Information Chapter 1
Using Input/Output
Contactors Input Contactor Precautions
Output Contactor Precaution
Common Bus/Precharge DC input drives do not have an internal precharge circuit. Therefore, the
following must be provided.
• Precharge capability must be provided in the system to guard against
possible damage.
• Disconnect switches must not be used between the input of the drive and a
common DC bus without the use of an external precharge device.
ATTENTION: A contactor or other device that routinely disconnects and
reapplies the AC line to the drive to start and stop the motor can cause drive
hardware damage. The drive is designed to use control input signals that will
start and stop the motor. If an input device is used, operation must not exceed
one cycle per minute or drive damage will occur.
ATTENTION: The drive start/stop/enable control circuitry includes solid state
components. If hazards due to accidental contact with moving machinery or
unintentional flow of liquid, gas or solids exist, an additional hardwired stop
circuit may be required to remove the AC line to the drive. An auxiliary braking
method may be required.
ATTENTION: To guard against drive damage when using output contactors, the
following information must be read and understood. One or more output
contactors may be installed between the drive and motor(s) for the purpose of
disconnecting or isolating certain motors/loads. If a contactor is opened while
the drive is operating, power will be removed from the respective motor, but the
drive will continue to produce voltage at the output terminals. In addition,
reconnecting a motor to an active drive (by closing the contactor) could produce
excessive current that may cause the drive to fault. If any of these conditions are
determined to be undesirable or unsafe, an auxiliary contact on the output
contactor should be wired to a drive digital input that is programmed as
“Enable.” This will cause the drive to execute a coast-to-stop (cease output)
whenever an output contactor is opened.
IMPORTANT Precharge circuitry is external to the drive and must be customer supplied.