Relay for Pre-Paid Energy Meter

Need more details on the current/voltage ratings of the required system, (signal voltage and switching voltage needed) then speccing a relay should be very straightforward. Open a catalogue or browse a suppliers site. Some things to be thought about would be ; Do you need DPCO (double pole changeover) for live and neutral ; do you want a mechanical/visual indicator for the changeover, is ease of installation a requirement, cost etc.

DesEng

METERING the Energy can be done by a Chip :

The ADE7761B is a high accuracy, fault-tolerant, electrical energy measurement IC intended for use with 2-wire distribution systems. The part specifications surpass the accuracy requirements as quoted in the IEC 62053-21 standard. The only analog circuitry used on the ADE7761B is in the ADCs and reference circuit. All other signal processing (such as multiplication and filtering) is carried out in the digital domain. This approach provides superior stability and accuracy over extremes in environmental conditions and over time. The ADE7761B incorporates a fault detection scheme similar to the ADE7751 by continuously monitoring both phase and neutral currents. A fault is indicated when the currents differ by more than 6.25%.

Maker >Analog Devices.

Chip lets out Pulses at Active energy taken in.

With these pulses you can terminate Power Consumption.

Ask Analog Devices--they will suggest-maye their own product to switch off.