V03-020620
SEM Three
Please note that this document is only a short user manual and does not handle every function. The complete manual is available
at
TECHNICAL CHARACTERISTICS
Power circuit
Input voltage
110 …. 264 Vac
Frequency
47 …. 63 Hz
Maximum consumption
2,5 …. 4,5 VA
Environmental conditions
Temperature range
-10 …. +60ºC
Humidity range
5 …. 95%
Mechanical characteristics
Enclosure material
Plastic UL94 – V0 Self-extinguishable
Protection grade
IP30
Unit dimensions (Width x Height x Length)
18 x 70 x 109 mm
Weight
70 g
Mounting
DIN Rail (1 module)
Maximum working altitude
2000 m
Serial interface
Type
RS-485 three wires
Baud rate
9600 / 19200 / 38400 / 57600 / 115200 bps configurable
Data bits
8
Parity
Without parity / Even configurable
Stop bits
1 / 2 configurable
Characteristics and electrical security
Security
CAT III 300 V under EN 61010
Protection class
Class II
External current transformers
Series TRC and TRA (In / 0,250 A)
Standards
Standards
UNE EN 61010-1:2010, UNE-EN 61000-6-2, UNE-EN 61000-6-4
COMMUNICATION
The device comes equipped with a RS-485 communication port to read and write the parameters of the device or other devices
connected. The protocol used is Modbus RTU.
By default the device is configured with
peripheral number 72
(decimal) and
communication mode 4
(9600 bps, 8, N, 1). Using
the command for changing the device number it is possible to assign any other number (maximum FF in hexadecimal or 255 in
decimal).
In case you
don’t remember the slave number, you can return to default number and communication mode following this steps:
Power off the device.
Press permanently reset button.
Power on the device and stop pressing the reset button.
WORKING MODE
SEM Three
has 4 different working modes for measuring the electrical parameters of an installation. To
change the working mode you must change the value of register “Working mode” between mode 0
(default), 1, 2 or 3. Belong are shown the details of each mode:
Mode 0: L1, L2 and L3 single-phase. Sum of all values measured in three-phase parameters.
Mode 1: L2 and L3 single-phase. L1 equilibrated three-phase. Sum of all values measured in
three-phase parameters.
Mode 2: L3 single-phase. L1 and L2 equilibrated three-phase. Sum of all values measured in
three-phase parameters.
Mode 3: L1, L2 and L3 equilibrated three-phase. Sum of all values measured in three-phase
parameters.
Mode 0
L1
T
o
ta
l
th
re
e
-p
h
a
se
L2
L3
Mode 1
L1 (x3)
L2
L3
Mode 2
L1 (x3)
L2 (x3)
L3
Mode 3
L1 (x3)
L2 (x3)
L3 (x3)