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. 14-26

of the hardware limits is exceeded.

NB!

It is recommended to disable protection mode in hoisting applications (par. 14-26

Trip Delay at Inverter Fault

MG.11.N1.02 - VLT

is a registered Danfoss trademark

to zero which means that the drive will trip immediately if one

Trip Delay at Inverter Fault

1 Introduction

= 0)