ABB PPD512 A10-454000 control card
Command generationThe command generation calculates the necessary lead angle
av, by which the paralleling command must be advanced
due to closing time delay. The action ensures that the main
contacts close at precisely the right time. lf a reaches av at
the same time as paralleling release (CHK RELEASE), the
command is issued. Under synchronous conditions, ie,
permanent paralleling release during the adjustable monitoring
time, tsup, the CMD is also issued without taking the lead
angle into consideration.
Synchrocheck mode (paralleling monitoring)
In synchrocheck mode, only the measuring and monitoring
function blocks are active. The output relay is closed during
paralleling release.
From a synchronizing device, it is expected to close the
power circuit breaker at the correct time but also that, if
required, paralleling can take place whenever permissible.
Although the series connection of the output contacts of two
independently-functioning channels (dual-channel system),
which is usual in synchronizing systems, greatly increases
security against incorrect paralleling, it necessarily leads to a
reduction in availability.
Single or dual-channel?
Not every synchronizing system needs to be structured
according to the above pattern. The SYNCHROTACT® 5
single-channel synchronizing devices offer a high degree of
security and are often used in practice. However, security
can be significantly increased by means of dual-channel
systems. It is unlikely that the two channels - of which the
hardware and software are structured differently - will have
the same malfunction simultaneously. The extra cost of a
dual channel system can prove beneficial compared to the
damage arising from incorrect paralleling

Second, redundant synchronizing system?
Often, two redundant synchronizing systems are installed
in a single plant so that, in the event of one system failing,
the other can be used, thereby increasing availability. The
second system is often designed for manual synchronizing
with or without synchrocheck.
In addition, with SYNCHROTACT® 5, ABB offers two automatic
dual-channel systems in a single casing, thus avoiding
manual synchronizing.
Advantages of such a solution:
– No engineering and wiring costs for the second system
– Further increased security since all four output contacts
are normally operated in series
– No problems with synchronizing where the
manual synchronizing system is seldom used.
Specific settings for synchronizing and paralleling are stored
in a parameter set. Devices with seven parameter sets have
seven times the same parameters, with the possibility of
individual setting. That way, seven paralleling points with
individual settings may be operated. Firstly, the parameter
set, or the circuit breaker to be synchronized has to be
selected. Then the synchronizing process can be started.
The software-driven link between parameter set and
paralleling point guarantees the correct assignment of the
setting values to the related plant components.
Service control for commissioning and servicing
– Built-in service controls: keypad and LCD (standard)
– SynView PC tool (accessory) for local control:
PC / Ethernet (standard)
– SynView PC tool (accessory) via LAN (standard)
Operating control for normal synchronizing operation
– Digital inputs/outputs: conventional wiring (standard)
– Interface (Modbus, Profibus, LON, IEC 61850): remote controlled synchronizing operation (option)