Logic Schemes - Basler BE1-11g Instruction Manual

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Logic Schemes

A logic scheme is a group of logic variables that defines the operation of a BE1-11g. Each logic scheme is
given a unique name. This gives you the ability to select a specific scheme and be confident that the
selected scheme is in operation. One logic scheme is configured for typical control applications and is the
default active logic scheme. Only one logic scheme can be active at a given time. In most applications,
preprogrammed logic schemes eliminate the need for custom programming. Preprogrammed logic
schemes can provide more inputs, outputs, or features than are needed for a particular application. This
is because a preprogrammed scheme is designed for a large number of applications with no special
programming required. Unneeded logic block outputs can be left open to disable a function or a function
block can be disabled through operating settings.
When a custom logic scheme is required, programming time is reduced by modifying the default logic
scheme.
Default Logic Scheme
All BE1-11g protection systems are delivered with the default logic scheme pre-loaded in memory. If the
function block configuration and output logic of the default logic scheme meets the requirements of your
application, then only the operating settings (power system parameters and threshold settings) need to be
adjusted before placing the BE1-11g in service.
Details of Default Logic Scheme describes the characteristics of the logic scheme and how it combines to
create an Overcurrent Protection System for a radial system substation. A detailed description of the
default scheme is also provided.
The default logic scheme is designed to accommodate most common distribution or sub-transmission
radial system overcurrent coordination schemes. The protection engineer can adapt it by changing the
function block operation and settings. This eliminates the need to create a custom logic scheme.
It should be noted that the default logic scheme also illustrates typical ways of using or controlling various
functions. The user can choose to create a custom logic scheme by mixing the logic from the default
scheme. The flexibility of BESTlogicPlus allows the protection engineer to create a custom scheme that
exactly meets the requirements of the application.
Always remove the BE1-11g from service prior to changing or
modifying the active logic scheme. Attempting to modify a logic
scheme while the BE1-11g is in service could generate unexpected or
unwanted outputs.
Modifying a logic scheme in BESTCOMSPlus does not automatically
make that scheme active in the BE1-11g. The modified scheme must
be uploaded into the BE1-11g. See the paragraphs on Sending and
Retrieving Logic Schemes.
Operational settings are not included in the default logic scheme. Each
element, target, pickup setting, timing setting, etc. will have to be
enabled and programmed separately using the Settings Explorer in
BESTCOMSPlus.
Overview of Default Logic Scheme
The default logic scheme provides basic time and instantaneous overcurrent protection. Included
protective elements are 50-1, 50-2, 50-3, 51-1, 51-2, and 51-3. Functions such as breaker failure, virtual
breaker control, and protective voltage features are not enabled in this scheme. However, these features
can be activated through BESTCOMSPlus.
BESTlogic™Plus
Caution
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BE1-11g