Model:S253(For Transformer) Name: 3-Phase Electric Measuring Transformer Monitoring and Alarm Remotely The Cellular(GSM/GPRS/3G/4G/NB-IoT) 3-Phase Electric Measuring RTU is special designed for remote monitoring transformer, and measuring the 3-phase 3-wire, 3-phase 4-wire distribution power voltage, current, factor, watts, frequency, active power, reactive power, when overload or loss phase or exceed the pre-set value, then it will alert by SMS, Voice call, Cloud, APP, Wechat, Web Server, SCADA, HMI, DSC immediately. The Cellular 3-Phase Electric Measuring RTU is an industrial class, high reliability, high stability, and programmable Remote Terminal Unit (RTU). It embedded 32-Bit High Performance Microprocessor MCU, integrated special measurement chip and inbuilt industrial Cellular module. It provides 4 digital inputs, 2 relay outputs, 1 ambient sensor input for monitoring onsite temperature and humidity. The Cellular 3-Phase Electric Measuring RTU also can be used for monitoring the safety and security of the transformer, e.g. overload, phase loss, oil temperature, oil level, burglarproof, fall down etc. The Cellular 3-Phase Electric Measuring RTU can monitoring and operates the I/O ports by SMS, APP, Web Server, internet, timers and programmed inter-lock events automatically. Mainly Features: 1. Can be operated from anywhere, no distance limitation; 2. Quad band 850/900/1800/1900Mhz GSM GPRS Module inside. 3. 3G/4G/NB-IoT Modules are optional; 4. Modular design, can easily upgrade the cellular module if network upgrade; 5. Embedded ARM® Cortex�-M4 32 Bit RISC Core, 168 MHz inside, RTOS system, reliable performance with in-built watchdog; 6. Wide range power supply 12~36VDC with over voltage and phase-reversal protection; 7. Measurement range: 3-Phase 3-Wire, 3-Phase 4-wire, frequency: 45~65Hz, voltage: 500V, current 5A, 10A; 8. 4 digital inputs, compatibles dry and wet contact; 9. 2 relay output (5A/30VDC, 5A/250VAC), compatibles pulse outputs; 10. 1 ambient sensor input for monitoring onsite temperature and humidity; 11. Provide additional 4 analog inputs, compatibles 4~20mA or 0~5V, can be change to PT100 temperature probe to measure the oil level or oil temperature ;( Optional) 12. Supports phase loss, phase recovery, voltage overload, current overload detection and alarm; 13. Inbuilt inter-lock logic programmer and powerful timer program function; 14. Resend the data while communication failure and alert to users by SMS; 15. Inbuilt TCP/IP protocol stack, supports cloud, APP and web server applications and so on.