Adjustable power time delay electrical outlet with a fault detection feature for enhanced safety

https://doi.org/10.70228/CBJ2024062

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ABSTRACT

Safety is one of the top priorities in electrical installations, especially in electrical outlets, for these can cause serious injuries or even fatalities. Electrical shocks, fires, and explosions can result from faulty wiring and improper device plugging. This study aimed to design, develop, and test an adjustable power time delay electrical outlet with a fault detection feature for enhanced safety. The prototype was developed using three proximity sensors, a microcontroller, an ohmmeter, and a power supply. The proximity sensors were used to send a signal to the microcontroller to turn off the outlet's power when they detect the presence of a hand. An ohmmeter detected whether the connected device had a short circuit. Power was supplied to the electrical outlet only after a predetermined time delay. It was applied to three (3) different connected devices to ensure that none were short-circuited before activation. The prototype’s reliability was tested using the percent relative error of the obtained time delay results after ten (10) trials. The prototype’s usability was determined using a survey conducted among three distinct age groups: 5–14 years old, 15–64 years old, and 65 years and above. It was found that the percentage error of the average measured time was less than 1% for each predetermined time delay in different loads. Hence, the prototype effectively functions when the load is in a normal condition, providing power to the electrical outlet after the predetermined time delay and detecting a short circuit, which leaves the outlet in the off state. The usability test results confirm that the prototype is accessible across diverse age groups, highlighting its simple applicability and ease of use. The reliability test results, which achieved a 100% success rate on short circuit detection, validate the system’s robustness and reliability in fault detection, establishing its readiness for deployment in actual use, where operational safety and performance are essential, except for motor loads and heavy equipment, where tests can be further done.

Keywords: Short circuit, usability, reliability, microcontroller, proximity sensor