Danfoss VLT Programming Manual page 9

Introduction
1 1
metres from the frequency converter, i.e. in a front panel by
means of the installation kit option.
lsb
Least significant bit.
msb
Most significant bit.
MCM
Short for Mille Circular Mil, an American measuring unit for
cable cross-section. 1 MCM = 0.5067 mm
On-line/Off-line Parameters
Changes to on-line parameters are activated immediately
after the data value is changed. Changes to off-line
parameters are not activated until you enter [OK] on the
LCP.
Process PID
The PID control maintains the desired speed, pressure,
temperature, etc. by adjusting the output frequency to
match the varying load.
PCD
Process Control Data
Power Cycle
Switch off the mains until display (LCP) is dark – then turn
power on again
Pulse Input/Incremental Encoder
An external, digital pulse transmitter used for feeding back
information on motor speed. The encoder is used in
applications where great accuracy in speed control is
required.
RCD
Residual Current Device.
Set-up
You can save parameter settings in four Set-ups. Change
between the four parameter Set-ups and edit one Set-up,
while another Set-up is active.
SFAVM
Switching pattern called Stator Flux oriented Asynchronous
Vector Modulation (14-00 Switching Pattern).
Slip Compensation
The frequency converter compensates for the motor slip by
giving the frequency a supplement that follows the
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.
8
®
VLT HVAC Drive Programming Guide
Thermistor:
A temperature-dependent resistor placed where the
temperature is to be monitored (frequency converter or
motor).
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
2
.
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 automat-
ically. Trip may not be used for personal safety.
VT Characteristics
Variable torque characteristics used for pumps and fans.
VVC
If compared with standard voltage/frequency ratio control,
Voltage Vector Control (VVC
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
Power factor =
The power factor for 3-phase control:
I 1 x cos ϕ1
=
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
kW performance.
I RMS =
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.
®
MG.11.CB.02 - VLT is a registered Danfoss trademark
plus
plus
) improves the dynamics and
3 x U x I 1 cos ϕ
x U x I RMS
3
I 1
= since cos ϕ1 = 1
I RMS I RMS
I 1 2 + I 5 2 + I 7 2 + .. + I n 2
and I .
1 RMS
for the same
RMS