CT characteristics
Constant torque characteristics used for screw and scroll
refrigeration compressors.
Digital inputs
The digital inputs can be used for controlling various
functions of the frequency converter.
Digital outputs
The frequency converter features 2 solid-state outputs that
can supply a 24 V DC (maximum 40 mA) signal.
DSP
Digital signal processor.
ETR
Electronic thermal relay is a thermal load calculation based
on present load and time. Its purpose is to estimate the
motor temperature.
GLCP
Graphical local control panel (LCP 102)
HIPERFACE
®
HIPERFACE
®
is a registered trademark by Stegmann.
Initializing
If initializing is carried out (
parameter 14-22 Operation
Mode
), the programmable parameters of the frequency
converter return to their default settings.
Input functions
Control command
Start and stop the
connected motor with the
LCP or the digital inputs.
Functions are divided into
two groups.
Functions in group 1 have
higher priority than
functions in group 2.
Group
1
Reset, coasting stop, reset
and coasting stop, quick-
stop, DC braking, stop and
the [Off] key.
Group
2
Start, pulse start, reversing,
start reversing, jog, and
freeze output.
Table 18.1 Input Functions
Intermittent duty cycle
An intermittent duty rating refers to a sequence of duty
cycles. Each cycle consists of an on-load and an off-load
period. The operation can be either periodic duty or none-
periodic duty.
LCP
The local control panel (LCP) makes up a complete
interface for control and programming of the frequency
converter. The LCP is detachable and can be installed up to
3 m (10 ft) from the frequency converter, in a front panel
with the installation kit option.
The LCPl is available in 2 versions:
•
Numerical LCP 101 (NLCP)
•
Graphical LCP 102 (GLCP)
lsb
Least significant bit.
MCM
Short for mille circular mil, an American measuring unit for
cable cross-section. 1 MCM
≡
0.5067 mm
2
.
msb
Most significant bit.
NLCP
Numerical local control panel LCP 101.
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 [OK] is entered on the
LCP.
PID controller
The PID controller maintains the desired speed, pressure,
and temperature by adjusting the output frequency to
match the varying load.
PCD
Process data.
Power factor
The power factor is the relation between I
1
and I
RMS
.
Power factor =
3 × U × I
1 × COSϕ
3 × U × I
RMS
The power factor for 3-phase control:
=
I
1
× cosϕ1
I
RMS
=
I
1
I
RMS
since cosϕ1 = 1
The power factor indicates to what 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.
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 built-in DC coils produce a high power factor, which
minimizes the imposed load on the mains supply.
Preset reference
A defined preset reference set from -100% to +100% of the
reference range. Selection of 8 preset references via the
digital terminals.
Pulse input/incremental encoder
An external digital sensor used for feedback information of
motor speed and direction. Encoders are used for high-
speed accuracy feedback and in high dynamic applications.
The encoder connection is either via terminal 32 or
encoder option.
Pulse reference
A pulse frequency signal transmitted to the digital inputs
(terminal 29 or 33).
RCD
Residual current device. A device that disconnects a circuit
if there is an imbalance between an energized conductor
and ground. Also known as a ground fault circuit
interrupter (GFCI).
Appendix
Design Guide
MG37N102
Danfoss A/S © 6/2016 All rights reserved.
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