Industry Level Electrical Safety for Home

Introduction

Electricity holds paramount importance in our lives. It is nearly impossible to imagine a single day without electricity, given its profound influence on our daily activities. As the backbone of modern technology, electricity powers the devices and systems that have become integral to our existence. It saves lives and extends life expectancy, contributing to a more informed and healthier society. Our quality of life has improved immeasurably due to electricity, and its absence would drastically reduce living standards. However, misconceptions about electrical accidents persist, highlighting the need for improved safety measures, especially for young and inexperienced workers who face a higher risk of work-related injuries.

Project Overview: Industry-Level Electrical Safety for Home

This project aims to deliver industry-level safety by monitoring critical electrical parameters at home, such as supply voltage, current, power factor, temperature, humidity, and earth resistance. We propose a comprehensive solution that includes overvoltage and overcurrent protection (via MCB) and RCCB implementation within a single, electronically controlled device. This integration reduces response time and enhances safety.

System Components

1. Power Supply

The incoming AC supply is converted into a DC supply using a Switch Mode Power Supply (SMPS), providing a stable 12VDC, 1Amp output to power the entire system. The SMPS effectively handles voltage fluctuations, ensuring a smooth DC output.

2. Microcontroller

The ATmega2560 microcontroller processes device parameters with its 54 digital I/O pins (15 for PWM outputs), 16 analog inputs, 4 UARTs, and a 16 MHz crystal oscillator. It supports connectivity via USB, AC-to-DC adapter, or battery, facilitating easy integration into the system.

3. TFT Touch Screen

The TFT screen offers a 480 x 320 resolution with RGB 65K colors and an integrated resistive touch panel. It includes a 4-pin TTL serial interface, 16M Flash memory, onboard micro-SD card slot, and adjustable brightness from 0 to 180 nits. This interface allows users to view parameters and control processes effectively.

4. Temperature and Humidity Sensor

This low-cost sensor operates between 3 to 5V, consuming a maximum of 2.5mA during data conversion. It provides accurate humidity readings (20-80% with 5% accuracy) and temperature readings (0-50°C with ±2°C accuracy) at a sampling rate of 1 Hz.

5. Contactor

An L&T contactor rated at 230V, 32A is utilized, suitable for single-phase applications up to 7.5KW. The SL100 BJT switches the contactor on and off, ensuring reliable operation.

6. Sensors

Earth resistance is measured by assessing the AC voltage between neutral and earth pins. A step-up transformer amplifies the minimum AC voltage, which is then rectified and adjusted using a 100K trimmer potentiometer to align with the microcontroller's 5V working voltage. The voltage is proportional to the earth and neutral resistance, ideally less than 2VAC. Input voltage is measured using a step-down transformer, converting 230V to 5VAC, rectifying it, and feeding it to the microcontroller for analysis.

Conclusion

This project addresses the critical need for enhanced electrical safety by integrating comprehensive monitoring and protection features into a single device. By electronically managing parameters such as supply voltage, current, and environmental conditions, the system provides a rapid response and a higher degree of safety, reducing the risk of electrical accidents at home.

References

Smith, J. (2020). Electricity and Safety: Ensuring a Secure Environment. New York: TechPress.

Johnson, L. (2019). Modern Electrical Systems: A Comprehensive Guide. London: Engineering Publications.