DATAKOM DKG-705 User’s Manual
705_USER.doc
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5. MODES OF OPERATION
The modes of operation are selected either by pushing the front panel keys or using the external mode
select inputs. External inputs override the front panel selection. If none of the external inputs is active, the unit
resumes to the mode selected by the front panel. Following selected mode, the DKG-705 will have different
behavior.
OFF:
In this mode, the mains contactor will be energized if mains phase voltages and frequency are within the
programmed limits. The engine will be stopped.
AUTO:
It is used for genset and mains automatic transfer. If at least one of the mains phase voltages or the
mains frequency is outside limits, the mains contactor will be deactivated.
The diesel will be started for programmed times after the wait period. When the engine runs, the crank relay
will be immediately deactivated. The engine will run without load during engine heating period. After this, if
alternator phase voltages and frequency are within limits, the unit will wait for the generator contactor period
and the generator contactor will be energized.
When all the mains phase voltages and the mains frequency are within the limits, the engine will continue to
run for the mains waiting period. At the end of this period the generator contactor is deactivated and the mains
contactor will be energized. If a cooling period is given, the generator will continue to run during cooling period.
At the end of the period, the fuel solenoid will be de-energized and the diesel will stop. The unit will be ready
for the next mains failure.
If the operation of the genset is disabled by the
weekly schedule
, then the
AUTO
led will flash, and the
operation of the genset will be as in the
OFF
mode.
LOAD TEST:
It is used to test the genset under load. Once this mode is selected, the engine will run and the
load will be transferred to the genset. The genset will feed the load indefinitely unless another mode is
selected.
TEST:
It is used to test the generator when the mains are on, or keep the generator waiting in the emergency
backup mode. The operation of the generator is similar to the AUTO mode, but the mains contactor will not be
deactivated if the mains are not off. If the mains are off, mains contactor will be deactivated and the generator
contactor will be activated. When the mains are on again, a changeover to the mains will be made, but the
engine will be kept running unless another mode is selected. The emergency backup operation may be
prohibited using the program parameter
P_629
.
5.1 External Switching of the Operation Mode
The Mode of operation of the unit may also be selected by external inputs instead of front panel keys.
For this, at least one of the digital inputs should be programmed as an input to force one of the 4 operating
modes. The corresponding input’s
P_7x0
parameter should be set to
18
,
19
,
20
or
21
. The mode selection
signal may be a NO or NC contact, switching to either battery positive or battery negative. These selections
are made using parameters
P_7x5
and
P_7x6
.
The external selection input has a higher level of priority than the front panel keys. Thus if the
operating mode is forced by the external input, this will override the selection made by the front panel keys.
However, when the external selection signal goes off, the unit will resume to the mode selected by the front
panel keys.
If a front panel mode selection key is pressed while the external mode select input is active, then the
key selection will be stored and when the external selection signal goes off, the unit will resume to this mode.
