DCREG2 15P0059B3
DCREG4 USER MANUAL
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If the LOC SEQ LED is on or flashing, polarity may also be reversed by pressing the “REVERSE” key.
The internal reference, resulting from the application of the operators above, is displayed by par. M014,
M010, M011 and M012 respectively.
2.7.2 In order to obtain the Ref n reference applied to the ramps, it is possible to choose one of the
preset run references (up to a maximum of seven) preset in parameters
P211(212)(213)(214)(215)(216)(217) (default values: +5 %, + 20%, +10 %, 0 %, -5 %, -20 %, -10 %
respectively). To do so, select the reference concerned with a combination of max. three MDIx
configurable digital inputs, by programming parameters C130(131)(132)(133)(134)(135) at values
1:Preset Speed A, 2:Preset Speed B and 3:Preset Speed C (see the table contained in the chapter
dealing with parameters P211 … P217: the 1:Preset Speed A function is programmed by default on MDI4,
terminal 34). The above mentioned Reverse function may be applied to these preset running references
too. By introducing a preset running reference, the START contact closing is always required.
2.7.3 For the Ref n speed reference applied to the ramps, the user may select the allowable polarity
through par. P012 (default value: Bipolar). For said reference, the maximum value may also be defined
through parameter P013 and parameter P015 (default values: +100% and -100% respectively). This limit
is also valid for the n setpoint global reference. After programming a polarity of one sign only on parameter
P012, a minimum speed value is given both for the Ref n reference applied to the ramps and for n
setpoint global speed reference through p. P014 and p. P016 (default values: 0%). Anyway, disabling of
minimum speed can be achieved by closing one of the MDIx configurable digital inputs, once parameters
C130(131)(132)(133)(134)(135) have been programmed at value 9:MinSpdDisabled.
2.7.4 In case of tacho or enP/Nr feedback, and in the event of a feedback signal failure, it is possible to
set the automatic switching towards the armature feedback through par. C155 (default value: Alarm
enabled).
If the dynamic regulation of the field current in field weakening mode is enabled, par. P011 (default value
400 V) is to be set at the same value as par. C012 in order to keep the speed of rotation nearly constant in
case of feedback failure.
2.7.5 In case of armature feedback, the RxI drop compensation may be entered through par. P086
(default value: 100%) whose value represents the value per cent of par. P088 computed by the autotuning
function. The autotuning function may be enabled by setting par. P001 to 3:RxI.
2.7.6 Should the motor tend to turn slowly with a zero reference, i.e. when a speed error offset is
detected, it is possible to stop the motor by adjusting parameter P087 (default value: 0%).
2.7.7 A limitation of the firing angle value may be obtained both in the energy transfer towards the
load and in the energy regeneration towards the mains. Set parameter P230 (default value: 30° for
DCREG4 and 25° for DCREG2) and parameter P231 (default value: 150°) respectively.
2.7.8 To avoid possible speed overshoots due to quick variations of reference at constant load (drive in
current limit mode), or to avoid temporary speed losses in case of quick variations of load at constant
reference, it may be advisable to introduce the parameter auto adaptation (this function has been
disabled by default) through parameter P082 and any other related parameter. Refer to the ADAPTIVE
SPEED PARAMETERS chapter to know the different programming procedures required.
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