USER MANUAL – S203TA-D / S203RC-D
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8.
Using S203RC-D with a custom rogowski coil
S203RC-D can be used with Rogowski coil of various input full scale: +-50mV, +-100mV or +-200mV.
Factory calibration works with a +-100mV/1000A rogowski coil so, if you are using a different one you must
use a different multiplication factor into the current phase A,B and C user tarature (menu -> user tarature-
>current phase A,B,C).
For setting those coefficients you can use also the Easy Setup software.
For calculate the right coefficient use this formula:
𝐶𝑢𝑟𝑟𝑒𝑛𝑡 𝑈𝑠𝑒𝑟 𝑇𝑎𝑟𝑎𝑡𝑢𝑟𝑒
𝐴,𝐵,𝐶
=
(𝑆203𝑅𝐶 − 𝐷 𝐹𝑢𝑙𝑙 𝑆𝑐𝑎𝑙𝑒 𝐼𝑛𝑝𝑢𝑡 [𝑚𝑉])
𝑅𝑜𝑔𝑜𝑤𝑠𝑘𝑖 𝐹𝑢𝑙𝑙 𝑆𝑐𝑎𝑙𝑒 𝐼𝑛𝑝𝑢𝑡 [𝑚𝑉]
×
𝑅𝑜𝑔𝑜𝑤𝑠𝑘𝑖 𝐹𝑢𝑙𝑙 𝑆𝑐𝑎𝑙𝑒 𝑂𝑢𝑡𝑝𝑢𝑡 [𝐴]
1000
for example:
S203RC-D Input full scale of +-100mV and Rogowski coil of 100mV/1000A use 1,000
S203RC-D Input full scale of +-100mV and Rogowski coil of 100mV/500A use 0,500
S203RC-D Input full scale of +-100mV and Rogowski coil of 100mV/2000A use 2,000
S203RC-D Input full scale of +-200mV and Rogowski coil of 200mV/2000A use 2,000
WARNING
the S203RC-D Input full scale can be modified only by the Easy Setup software (the default is +-100mV).
9.
Serial Communication
A models S203TA-D and S203RC-D feature it’s the serial communication ability.
Two serial ports are available: a RS485 port and an USB port.
The RS485 port and USB port can’t work both at the same time, the first byte received from the USB port
will switch the communication from RS485 to USB.
After 5 seconds without a USB byte received the communication return to RS485.
The protocol supported for both ports is Modbus RTU slave, for more information about this protocol
please refer to Modbus specification website:
http://www.modbus.org/specs.php