Danfoss VLT HVAC Basic Drive FC 100 Series Design Manual page 8

How to Read this Design Gui...
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 locked may not be used for personal
safety.
VT Characteristics
Variable torque characteristics used for pumps and fans.
plus
VVC
If compared with standard voltage/frequency ratio control,
plus
Voltage Vector Control (VVC
and the stability, both when the speed reference is
changed and in relation to the load torque.
1.1.6 Power Factor
The power factor is the relation between I
3 × U × I 1 × COS ϕ
Power factor =
U × I RMS
3 ×
The power factor for 3-phase control:
I 1 × cos ϕ1 I 1
= = since cos ϕ1 = 1
I RMS I RMS
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
same kW performance.
I RMS = I 1 2 + I 5 2 + I 7 2 + . . + I n 2
In addition, a high power factor indicates that the different
harmonic currents are low.
The frequency converters' built-in DC coils produce a high
power factor, which minimizes the imposed load on the
mains supply.
VLT HVAC Basic Drive Design Guide
) improves the dynamics
and I .
1 RMS
for the
RMS
®
MG.18.C2.02 - VLT is a registered Danfoss trademark
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