14
Air Circuit Breakers
BT2 series
Communicative
To achieve the function of "four kinds of remote operation" at
long distance by communication interface of the circuit breaker,
namely, remote control, remote communication, remote
adjustment and remote detection.
• Communication protocol : The application of Modbus-RTU mode
• Communication interface
• Standard interface: RS-485.
• Baud rate: 19200bps (in favour of 1200, 2400, 4800, 9600, 38400bps)
• Communication address:1-119.
• Byte format: First bit as start bit, eighth bit as data bit, second bit as stop bit,
even check (in favour of non-check, odd check .)
• Network characteristic
• Twisted-pair shielded cables serve as communication lines.
• One line can link up 32 pieces of communicative circuit breakers at the same
time (16 pieces of circuit breakers with components of draw-out socket
communication module).
• Wiring distance is 1200m at maximum but the distance of communication
can be extended by equipping with repeaters additionally.
Communication data
• Real-time current, voltage fundamental current, fundamental voltage, power,
power factor, electric energy, harmonic current or voltage ratio and total
distortion of current or voltage.
• State data of circuit breakers such as alarm, fault, energy-storage, under-
voltage, ready-for-switching-on, and the positions of switching-on and
switching-off etc.
• The position of main body of the circuit breaker (components of
communication module of draw-out socket for BT2 need to be purchased).
• The fetching and modification of the setting values of circuit breakers.
• Recorded data of fault last time.
• Outline data such as serial numbers and the type etc of circuit breakers.
• Long-distance operation if switching-on and switching-off.
• Circuit breakers can be switched on or off in the long-distance.
• Wiring terminals for communication.
2
1
4
1
0
1
8
1
1
3
1
9
7
Terminal
Signal
Function
8
DATA+(A+)
Receive/transmit data
10
DATA-(B-)
Receive/transmit data
12
SH
In connection with shielded layer of
communication line
Blue
White
One group
Shielding layer
Standard twisted-pair shielded cable
Communication cable
Note: please use the type of communication cable with the shielding layer and
approach to circuits with strong electricity should be avoided as far as
possible when wiring in the cabinet.
Colour
Signal
Funation
Blue
DATA+
Receive/transmit data
White
DATA−
Receive/transmit data
Shielding layer
GND
Grounding
As the above diagram shows, a group of twisted-pair lines
in the standard communication cable is employed as the
communication line of 485 and the sheilding layer is grounded.
The actual practice should be possibly different such as the
application of the colour of the twisted-pair line. Users could
define the ways of cable's usage by themselves but the
definition of the signal of each line in the cable should be made
clear in advance.
Communication
