INSTALLATION
146
NA30 - Manual - 04 - 2022
Block circuits may be connected to equipment located in a different switchboard: For the aim of
reliability, it is recommended to use conductors having a cross sectional thickness of at least 1 mm
2
and to not exceed 5 km in length. For connections that are particularly critical in terms of electro-
magnetic pollution, it is recommended to use BFO adaptor modules with fibre optic connection.
When devices without committed pilot wire circuits must be embedded (devices other than Pro_N),
or in the event that further I/O circuits are need, output relays and binary inputs can be customized
to work in the logic selectivity system together with the committed pilot wire circuits.
A ring network example
[1]
is shown on the following pages.
Block out signals concerning the NA30 devices (S3.1, S3.2 e S3.3) are split on two isolated outputs by
means of MRB devices (B2.1, B2.2 and B2.3) to allow proper selectivity logic operation.
Nota 1 All diagram must be considered just as example; they cannot be comprehensive for real applications.
Block-sch.ai
Logic selectivity with BFO
BLIN1
BLIN1
BLIN1
Block2 IPh
BLOUT1
BLOUT1
TRIP I>>
TRIP I>>
TRIP I>>
TRIP I>>
Any device
Block-misto.ai
Example for accelerated protection system with joint use of binary input and pilot wire links
BLIN1
BLOUT1
U
aux
BINARY INPUTS
A19
A20
A21
A22
BLOCK OUT
BLOCK IN
A17
A15
BLOUT-
BLOUT+
A16
A18
TRIP I>>
TRIP I>>
START I>>
TRIP I>>
PRO_N
S1
S2
S3
PRO_N
BINARY INPUTS
A19
A20
A21
A22
BLOCK OUT
BLOCK IN
A17
A15
BLOUT-
BLOUT+
A16
A18
