Installation manual

General Installation Information 1-9
Using Input/Output
Contactors
Input Contactor Precautions
Output Contactor Precaution
Common Bus/Precharge
The following information must be read and understood:
• DC input drives do not have an internal precharge. Therefore:
– Precharge capability must be provided in the system to guard against
possible damage, and
– 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.
Important:Precharge circuitry is external to the drive.
!
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.