Many countries regard smart grid as the development direction of the future grid, so as to build a flexible, clean, safe, economic, friendly and other performance of the grid. In view of the domestic power grid situation, we have designed a smart meter reading module protection solution.

Background

1. There is a lot of clutter in the domestic power grid, and the power grid is too dirty, resulting in damage to the meter reading module of the meter

2.longer wires in the grid, easy to sense lightning surges, which in turn burn out the electronic modules in the meter.

Protection Circuit Diagram and our Electronic components

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Gas Discharge Tube Parameters

GDT【SC2E8-800ML】DC Spark-over Voltage：800V±20%，Nominal Impulse Discharge Current（8/20μS）：10kA，Maximum Capacitance＜1pF，Minimum Insulation Resistance 1GΩ(at 100v); Advanced Protection

PTC Resettable Fuse

PTC1/PTC2【SC250-120U】Vmax：250V；Imax：10A；Ihold：120mA；Remark：DIP Type

MOV1/MOV2/MOV3【20D681K】Varistor Voltage（at1mA）：621V-748V，Withstanding Surge Current（8/20μS）：6500A，Maximum Clamping Voltage（at5A）：1120V

Thyristor Surge Suppressors(TSS)

TSS【P0080SB】Vdrm：6V；Vs：25V；Vt：4V；Idrm：5μA，Is：800mA，It：2.2A；Ih：50mA，Co：20-150pF，@10/700μS, 4KV

Applications

1. Meter reading module

2. Meter collector, etc.

The Solutions Notes

1. The AC input port can prevent I EC61000-4-5 combined wave difference common mode 6KV;

2. The power carrier port can prevent the power input clutter signal

3. The 485 ports can meet the UT-T K21 standard surge test requirements, the protection level is 10/ 700uS differential common mode 6KV,

4.Pass power line induction and contact tests