3Vf Circuit-Breakers; Design And Mode Of Operation; Communication Via Profibus-Dp - Siemens 3VF Series Communications Manual

Communication System Manual

2 3VF circuit-breakers

2.1 Design and mode of operation

2.1.1 Communication via PROFIBUS-DP

3VF circuit-breakers can communicate via PROFIBUS-DP by means of SIMOCODE-DP (Siemens
Motor Protection And Control Device - Decentralized Peripherals, or product code 3UF5). This
communication-capable branch is available for currents from 63 A to 800 A for circuit-breakers 3VF3 to
3VF7.
The circuit-breaker assumes the tasks of overload and short-circuit protection for the plant section.
SIMOCODE-DP measures the current in the feeder in the highest loaded phase and makes it available
via the bus. The customer wires control functions such as opening/closing (ON/OFF) and monitoring of
the switching state (whether the circuit-breaker is ON or OFF or whether it has tripped due to a fault)
between SIMOCODE-DP and the circuit-breaker (see section entitled "Connecting 3VF to the
communication system"). The motorized operating mechanism and internal accessories, such as alarm
and auxiliary switches, must be taken into consideration when ordering the circuit-breakers.
(See section entitled Selection and ordering data).
SIMOCODE-DP (3UF5) acts as a control and measuring unit in conjunction with the 3VF circuit-breaker.
The overload and short-circuit protection functions are not affected by the connection to SIMOCODE-DP
or by a PROFIBUS-DP failure.
SIMOCODE-DP measures the following operational data as standard and makes them available via
PROFIBUS-DP:
Maximum phase current as a % of the setting current in the highest loaded phase:
(Prerequisite: Setting current I
the circuit-breaker. This value must be entered prior to start-up in the field "Setting current 1".)
Operational state of circuit-breaker (ON/OFF/TRIPPED = trip due to overload or short-circuit).
Event signals:
I>I Signal at upper current limit, default setting of 120 %, can be parameterized.
n
I<I Signal at lower current limit, default setting of 80 %, can be parameterized.
n
The following control commands are possible via PROFIBUS-DP:
Switch circuit-breaker ON/OFF
RESET circuit-breaker following overload or short-circuit
Version 1.0 (05/98)
of SIMOCODE-DP corresponds to setting current or rated current I
e
© Copyright Siemens AG 1998. All rights reserved.
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