Danfoss VLT Refrigeration Drive FC 103 Programming Manual page 11

Introduction
plugs. For information about the discharge time,
see Table 1.4.
•
[Off] does not disconnect the mains supply and
must not be used as a safety switch.
•
Ground the equipment properly, protect the user
against supply voltage, and protect the motor
against overload in accordance with applicable
national and local regulations.
•
The ground leakage current exceeds 3.5 mA.
Ensure correct grounding of the equipment by a
certified electrical installer.
•
Do not remove the plugs for the motor and
mains supply while the frequency converter is
connected to mains. Check that the mains supply
has been disconnected and that the necessary
time has elapsed before removing motor and
mains plugs.
•
The frequency converter has more voltage
sources than L1, L2, and L3, when load sharing
(linking of DC intermediate circuit) or external 24
V DC is installed. Check that all voltage sources
have been disconnected and that the necessary
time has elapsed before commencing repair work.
For information about the discharge time, see
Table 1.4.
NOTICE
When using the Safe Torque Off, always follow the
®
instructions in VLT Frequency Converters - Safe Torque
Off Operating Instructions.
NOTICE
Control signals from, or internally within, the frequency
converter 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,
these control signals must not be relied on exclusively.
MG16H202
Programming Guide
NOTICE
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 regulations, for example, law on
mechanical tools and regulations for the prevention of
accidents.
Protection mode
Once a hardware limit on motor current or DC-link voltage
is exceeded, the frequency converter enters the 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 the robustness of the
frequency converter while re-establishing full control of the
motor.
Protection mode can be disabled by setting
parameter 14-26 Trip Delay at Inverter Fault to 0, which
means that the frequency converter trips immediately if 1
of the hardware limits is exceeded.
NOTICE
Disabling protection mode in hoisting applications
(parameter 14-26 Trip Delay at Inverter Fault = 0) is
recommended.
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