Sunways AT 2700, User Manual

Page: 10 / 142

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· CAN bus interface for interconnecting
several solar inverters
· S0 pulse output for controlling large
displays
· Alarm relay for realising simple moni-
toring locally
· Interface for connecting an irradiation
and temperature sensor
Data logging
The AT Solar Inverter is equipped with
internal data logging for recording and
saving system data:
· 5-minute mean values of voltages,
currents, output, temperature and ir-
radiation (if sensor is installed)
· 5-minute, daily, monthly and annual
values of energy yield
· Memory for malfunction messages
Grid monitoring
The AT Solar Inverter assumes the task
of grid monitoring for the protection of
the unit and persons. In case of abnormal
grid conditions, feeding is immediately
interrupted and the solar inverter discon-
nects from the grid by triggering the grid
relay.
Design of solar inverter
The principle design of the AT Solar In-
verters can be recognised from the block
diagram. The most important character-
istic of the inverter is the earthing of the
solar generator, i.e. the negative terminal
is directly connected to the neutral con-
ductor on the grid.
The solar generator voltage connected to
the inverter input is always positive and is
initially adapted by the DC actuator and
then converted to alternating current by
the high-efficiency HERIC
® inverter. The
AC connection is made with 5 wires for a
3-phase feed point (3-phase AC current
connection) due to the 3-phase passive
grid monitoring, whereby feeding is
only single-phase. A 3-wire connection
is made at the single-phase feed point
(alternating current connection).