DKG-307 User Manual V-37 (01.03.2012)
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The Delayed Mains Simulation feature is used in battery backed up telecom systems where
batteries are able to supply the load during a certain period. The genset is requested to run only when
battery voltage drops below the critical level. Once the engine runs, the rectifier system starts charging
the batteries and the battery voltage goes up immediately. Thus the engine should continue to run a
programmed period for effective charging. The critical battery voltage level will be detected by an
external unit which provides the digital Simulate Mains signal for the genset control unit.
The unit offers an optional SIMULATE MAINS signal input. The SPARE-2 digital input may be
assigned as Simulate Mains using program parameter P_084.
It is also necessary to set the ACTION program parameter of the related input to 3 in order to
prevent any alarms generated from this input.
The SIMULATE MAINS signal may be a NO or NC contact, switching to either battery positive or
battery negative. These selections are made using the programming menu.
If the Delayed Simulate Mains program parameter (P_085) is set to 1 and the input signal is
active when the genset is not feeding the load, the mains phases are not monitored and supposed to
be inside limits. This will prevent the genset from starting when the simulate mains signal is present
(batteries charged). The genset will start when mains voltages are out of limits and the simulate mains
signal not present.
If the genset is running when the signal is applied, then MAINS SIMULATION will be
prevented during P_086 Flashing Relay Timer program parameter. After this, usual Mains Waiting
and Cooldown cycles will be performed before engine stop. When the SIMULATE MAINS signal is
present, the front panels mimic diagram‟s mains LEDs will reflect the mains voltages as present.
When the signal is passive, the unit will revert to normal operation and monitor the mains
voltage status.
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