ABB RET 541 Product Manual page 5

Design
Transformer Terminal
The transformer terminals RET 541, RET
543 and RET 545 differ from each other
regarding the number of digital inputs and
outputs available. Please, refer to section
"Ordering" for more details.
The functions of the RET 54_ transformer
terminal are categorized as:
• protection functions
• measurement functions
• control functions
• condition monitoring functions
• communication functions
• general functions
• standard functions
The functions are further divided to three sub-
sets that correspond to different functionality
levels, refer to section "Ordering Informa-
tion"
Protection functions
Protection is one of the most important func-
tions of the RET 54_ transformer terminal.
The protection function blocks (e.g.
NOC3Low) are independent of each other
and have e.g. their own setting groups and
data recording.
The protection function blocks are docu-
mented on the CD-ROM "Technical Descrip-
tions of Functions" (1MRS750889-MCD)
Measurement functions
The measurement function blocks are docu-
mented on the CD-ROM "Technical Descrip-
tions of Functions" (1MRS750889-MCD)
Control functions
The control functions are used to indicate the
position of switching devices, i.e. circuit
breakers and disconnectors, and to execute
open and close commands for controllable
switching devices in the switchgear. Further-
more, there are supplementary functions for
control logic purposes, e.g. on/off switches,
MIMIC alarm, LED control, numerical data
for the MIMIC and logic controlled position
selection.
The control functions configured using the
Relay Configuration Tool can be associated
with position indicators that are part of the
MIMIC configuration picture displayed on
the HMI. Position indicators are used to indi-
cate the position of switching devices via the
MIMIC picture and to control them locally.
RET 541, RET 543, RET 545
The control function blocks are documented
on the CD-ROM "Technical Descriptions of
Functions" (1MRS750889-MCD)
Condition monitoring functions
The condition monitoring function blocks are
documented on the CD-ROM "Technical
Descriptions of Functions" (1MRS750889-
MCD)
General functions
Additional functions are available for differ-
ent general purposes to be used in logics such
as activation of HMI backlight, switchgroups,
and resetting of operation indications, latched
output signals, registers and disturbance
recorder.
Communication functions
The RET 54_ transformer terminal provides
the IEC_103, Modbus, DNP 3.0, SPA and
LON serial communication protocols.
In a customer-specific transformer terminal
configuration, special events can be gener-
ated via an EVENT230 event function.
EVENT230 is documented on the CD-ROM
"Technical descriptions of Functions"
(1MRS750889-MCD).
Standard functions
Standard functions are used for logics, such
as interlocking, alarming and control
sequencing. The use of logic functions is not
limited and the functions can be intercon-
nected with each other as well as with protec-
tion, measurement, power quality, control,
condition monitoring and general functions.
In addition, the digital inputs and outputs as
well as LON inputs and outputs can be con-
nected to standard functions by using the
Relay Configuration Tool.
The standard function blocks are documented
on the CD-ROM "Technical descriptions of
Functions" (1MRS750889-MCD).
Other functions
Low auxiliary voltage indication
The RET 54_ transformer terminal is pro-
vided with a low auxiliary voltage indication
feature. The power supply module issues an
internal alarm signal when a drop in the
power supply voltage is detected (ACFail,
active low). The alarm signal is activated if
the power supply voltage falls about 10%
below the lowest rated DC input voltage of
the power supply module.
1MRS755543
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