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measured motor load keeping the motor speed almost
constant.
Smart Logic Control (SLC)
The SLC is a sequence of user defined actions executed
when the associated user defined events are evaluated as
true by the Smart Logic Controller. (Par. group 13-**
Smart
Logic Control (SLC)
.
STW
Status Word
FC Standard Bus
Includes RS -485 bus with FC protocol or MC protocol. See
8-30 Protocol
.
Thermistor:
A temperature-dependent resistor placed where the
temperature is to be monitored (frequency converter or
motor).
THD
Total Harmonic Distortion state the total contribution of
harmonic.
Trip
A state entered in fault situations, e.g. if the frequency
converter is subject to an over-temperature or when the
frequency converter is protecting the motor, process or
mechanism. Restart is prevented until the cause of the
fault has disappeared and the trip state is cancelled by
activating reset or, in some cases, by being programmed
to reset automatically. Trip may not be used for personal
safety.
Trip Locked
A state entered in fault situations when the frequency
converter is protecting itself and requiring physical
intervention, e.g. if the frequency converter is subject to a
short circuit on the output. A locked trip can only be
cancelled by cutting off mains, removing the cause of the
fault, and reconnecting the frequency converter. Restart is
prevented until the trip state is cancelled by activating
reset or, in some cases, by being programmed to reset
automatically. Trip may not be used for personal safety.
VT Characteristics
Variable torque characteristics used for pumps and fans.
VVC
plus
If compared with standard voltage/frequency ratio control,
Voltage Vector Control (VVC
plus
) improves the dynamics
and the stability, both when the speed reference is
changed and in relation to the load torque.
60
°
AVM
Switching pattern called 60
°
Asynchronous Vector
Modulation (
14-00 Switching Pattern
).
Power Factor
The power factor is the relation between I
1
and I
RMS
.
Power factor =
3
x U x I1 cosϕ
3
x U x IRMS
The power factor for 3-phase control:
= I1 x cosϕ1
IRMS
=
I1
IRMS
since cosϕ1 = 1
The power factor indicates to which extent the frequency
converter imposes a load on the mains supply.
The lower the power factor, the higher the I
RMS
for the
same kW performance.
IRMS = I1
2 + I
5
2 + I
7
2 + .. + In2
In addition, a high power factor indicates that the different
harmonic currents are low.
All Danfoss frequency converters have built-in DC coils in
the DC link to have a high power factor and to reduce the
THD on the main supply.
How to Read this Design Gui...
FC 300 Design Guide
10
MG.33.BD.02 - VLT
®
is a registered Danfoss trademark
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