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W A R N I N G
DISCHARGE TIME
The drive contains DC-link capacitors, which can remain charged even when the drive is not powered. High voltage can be
present even when the warning indicator lights are off. Failure to wait the specified time after power has been removed before
performing service or repair work can result in death or serious injury.
Stop the motor.
Disconnect all power sources, including permanent magnet type motors.
Wait for capacitors to discharge fully. The discharge time is shown on the nameplate.
Verify full discharge by measuring the voltage level.
N O T I C E
USING THE SAFE TORQUE OFF
When using the Safe Torque Off, always follow the instructions in VLT
®
Frequency Converters - Safe Torque Off Operating
Instructions.
N O T I C E
CONTROL SIGNALS
Control signals from, or internally within, the drive may in rare cases be activated in error, be delayed, or fail to occur entirely.
When used in situations where safety is critical, for example when controlling the electromagnetic brake function of a hoist
application, do not rely on these control signals exclusively.
N O T I C E
HAZARDOUS SITUATIONS
Hazardous situations must be identified by the machine builder/integrator who is responsible for considering the necessary
preventive means. More monitoring and protective devices may be included, always according to valid national safety regu-
lations, for example law on mechanical tools and regulations for the prevention of accidents.
2.2 Safety Regulations
Crane, lifts, and hoists
The controlling of external brakes must always have a redundant system. The drive can in no circumstances be the primary safety
circuit. Comply with relevant standards, for example:
Hoists and cranes: IEC 60204-32
Lifts: EN 81
Protection mode
Once a hardware limit on motor current or DC-link voltage is exceeded, the drive enters protection mode. Protection mode means a
change of the PWM modulation strategy and a low switching frequency to minimize losses. This continues for 10 s after the last fault
and increases the reliability and robustness of the drive while re-establishing full control of the motor.
In hoist applications, protection mode is not usable because the drive is unable to leave this mode again. Therefore it extends the
time before activating the brake, which is not recommended. Protection mode can be disabled by setting
parameter 14-26 Trip De-
lay at Inverter Fault
to 0, which means that the drive trips immediately if 1 of the hardware limits is exceeded.
N O T I C E
Disabling protection mode in hoisting applications is recommended.
AU275636650261en-000101 / 130R0334
14 | Danfoss A/S © 2022.12
Safety
VLT AutomationDrive FC 301/302
Programming Guide