GE AF-650 GP Programming Manual page 10

Touching the electrical parts may be fatal - even after the equipment has been disconnected from mains.
Also make sure that other voltage inputs have been disconnected, such as external 24 V DC, load sharing (linkage of DC intermediate circuit), as well as the motor
connection for kinetic back up.
Systems where frequency converters are installed must, if necessary, be equipped with additional monitoring and protective devices according to the valid safety
regulations, e.g law on mechanical tools, regulations for the prevention of accidents etc. Modifications on the frequency converters by means of the operating
software are allowed.
Hoisting applications:
The frequency converter functions for controlling mechanical brakes cannot be considered as a primary safety circuit. There must always be a redundancy for
controlling external brakes.
Protection Mode
Once a hardware limit on motor current or dc-link voltage is exceeded the drive will enter "Protection mode". "Protection mode" means a change of the PWM
modulation strategy and a low switching frequency to minimize losses. This continues 10 sec after the last fault and increases the reliability and the robustness
of the drive while re-establishing full control of the motor.
In hoist applications "Protection mode" is not usable because the drive will usually not be able to leave this mode again and therefore it will extend the time before
activating the brake – which is not recommendable.
The "Protection mode" can be disabled by setting par. SP-26 Trip Delay at Drive Fault to zero which means that the drive will trip immediately if one of the hardware
limits is exceeded.
NB!
It is recommended to disable protection mode in hoisting applications (par. SP-26 Trip Delay at Drive Fault = 0)
AF-650 GP Programming Guide
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