User Manual Instruction Manual

Wiring Requirements for the Drive 4-3
4.1.1 Power Wire Sizes
Input power wiring should be sized according to applicable codes to handle the drive’s
continuous-rated input current. Output wiring should be sized according to applicable
codes to handle the drive’s continuous-rated output current. See table 5.2 for
minimum and maximum wire sizes.
4.1.2 Using Input/Output Contactors
Input Contactor Precautions
Output Contactor Precaution
!
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 AC input
disconnect 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 disconnect
the AC line from 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. Disconnecting
a motor under load can cause damage to the contactor as well as
the drive because the DV/DT (change in voltage/Change in time) is
severe causing a rapid increase in current at the contacts and the
resultant current draw from the drive. If at all possible, a control
scheme should send a stop signal to the drive to minimize any
energy being sent to the motor before opening the contactors. 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, helping to prevent the drive
from operating without the contactors’ prior closure.