Yaskawa Z1000 AC Drive HVAC - Manual (Page 17)

DC Injection Braking
NOTICE: Excessive current during DC Injection Braking and excessive duration of DC Injection Braking can cause motor overheat.
Acceleration/Deceleration Times
Acceleration and deceleration times are affected by the amount of torque generated by the motor, the load torque, and the
inertia moment. Set a longer accel/decel time when Stall Prevention is enabled. The accel/decel times are lengthened for as
long as the Stall Prevention function is in operation. Install one of the available braking options or increase the capacity of the
drive for faster acceleration and deceleration.
n General Handling
Wiring Check
NOTICE: Do not connect power supply lines to output terminals U/T1, V/T2, or W/T3. Failure to comply will destroy the drive. Be sure to
perform a final check of all sequence wiring and other connections before turning on the power and also check for short circuits on the
control terminals, which may damage the drive.
Selecting a Circuit Breaker or Circuit Interrupter
Yaskawa recommends installing a Ground Fault Circuit Interrupter (GFCI) to the power supply side. The GFCI should be
designed for use with AC drives (e.g., Type B according to IEC/EN 60755).
Select a Molded Case Circuit Breaker (MCCB) or GFCI with a rated current 1.5 to 2 times higher than the drive rated input
current to avoid nuisance trips caused by harmonics in the drive input current.
Magnetic Contactor Installation
WARNING! Fire Hazard. Shut off the drive with a magnetic contactor (MC) when a fault occurs in any external equipment such as braking
resistors. Failure to comply may cause resistor overheating, fire, and injury to personnel.
NOTICE: To get the full performance life out of the electrolytic capacitors and circuit relays, refrain from switching the drive power supply
off and on more than once every 30 minutes. Frequent use can damage the drive. Use the drive to stop and start the motor.
Inspection and Maintenance
WARNING! Electrical Shock Hazard. Capacitors in the drive do not immediately discharge after shutting off the power. Wait for at least the
amount of time specified on the drive before touching any components after shutting off the power. Failure to comply may cause injury to
personnel from electrical shock.
WARNING! Electrical Shock Hazard. When a drive is running a PM motor, voltage continues to be generated at the motor terminals after
the drive is shut off while the motor coasts to stop. Take the precautions described below to prevent shock and injury:
∙ In applications where the machine can still rotate after the drive has fully stopped a load, install a switch to the drive output side to disconnect
the motor and the drive.
∙ Do not allow an external force to rotate the motor beyond the maximum allowable speed or to rotate the motor when the drive has been
shut off.
∙ Wait for at least the time specified on the warning label after opening the load switch on the output side before inspecting the drive or
performing any maintenance.
∙ Do not open and close the load switch while the motor is running.
∙ If the motor is coasting, make sure the power to the drive is turned on and the drive output has completely stopped before closing the load
switch.
WARNING! Burn Hazard. Because the heatsink can get very hot during operation, take proper precautions to prevent burns. When replacing
the cooling fan, shut off the power and wait at least 15 minutes to be sure that the heatsink has cooled down. Failure to comply may cause
burn injury to personnel.
Wiring
Yaskawa recommends using ring terminals on all drive models. Use only the tools recommended by the terminal manufacturer
for crimping.
Transporting the Drive
NOTICE: Never steam clean the drive. During transport, keep the drive from coming into contact with salts, fluorine, bromine, phthalate
ester, and other such harmful chemicals.
u Motor Application Precautions
n Standard Induction Motors
Low-Speed Range
The cooling fan of a standard motor should sufficiently cool the motor at the rated speed. As the self-cooling capability of
such a motor reduces with the speed, applying full torque at low speed will possibly damage the motor. Reduce the load torque
as the motor slows to prevent motor damage from overheat. Figure i.2 shows the allowable load characteristics for a Yaskawa
standard motor. Use a motor designed specifically for operation with a drive when 100% continuous torque is needed at low
speeds.
i.2 General Safety
YASKAWA ELECTRIC TOEP YAIZ1U 03A YASKAWA AC Drive – Z1000 User Manual 17