30 ATS115-ATS115Plus User’s Manual
In this mode, the device has to guarantee, in any situation, to power the Load. In order to comply with
this work, the device carries out a constant supervision of both sources for voltage/frequency faults or
for the configuration of hours of work or changeover requests related to the digital inputs functions.
See below an example of a system configured with the Source A connected to the Mains and the
Source B connected to a Genset.
Sequence with Mains live:
If the Mains is in the normal values configured during the installation, the ACB contactor is
closed and the Load is supplied by the Mains. The Genset is not operating and the BCB
contactor is opened.
Sequence with Mains failure:
If the Mains values differ from those configured during the installation (for example in case of
Blackout), and the Load is no longer supplied correctly, the device will activate the start
operating sequence of the Genset:
1) Engine start command and wait, with voltage/frequency supervision, for the stable
working conditions of the Genset. An acoustic warning will be activated if the Genset
does not reach the normal operating conditions for the changeover after the time set.
2) Changeover command between ACB and BCB contactors with consequent switch of the
Load on the Genset.
3) The Genset still supplies the Load. The controller constantly monitor the electric
measurements of Mains and Genset; it waits for the Mains to be back in the correct
parameters.
Mains back after Blackout:
The Load is supplied by the Genset with BCB closed and ACB opened, but the Mains is back
after the Blackout. If the Mains is stable and in tolerance (normal value), the device will start
the Mains back sequence with the standard procedure:
1) Changeover command between BCB and ACB with consequent switch of the Load on
the Mains.
WARNING! The switch between ACB and BCB o vice versa, creates a Blackout on
the Load line. The Load will be disconnected for the time needed to ensure a correct
switch of the contactors.
2) The Genset start operating command is immediately removed or delayed with
programmable parameter. An acoustic warning will be activated if the Genset does not
stop.
3) The Load is supplied by the Mains with ACB closed. The Genset is not working with BCB
opened, ready for a possible new intervention.
INFORMATION: The working sequence described above is generic and in some cases
may not correspond to the one of your system. For further information, contact the
Installer/Manufacturer.
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