Published Paper Details:

Three-phase induction motors form the backbone of industrial drives, yet they remain vulnerable to thermal overload, overcurrent and abnormal supply voltage, each of which shortens winding life and causes unplanned downtime. Conventional thermal overload relays and fuses act only after a fault has fully developed, and they retain no record of the operating conditions that preceded the trip, so continuous monitoring of the machine is required if abnormal conditions are to be detected early and the motor isolated before damage occurs. This paper reports the design, construction and operation of a prototype Internet of Things based monitoring and protection system built around an ESP32 microcontroller. Analogue temperature, current and voltage sensing channels are connected to the microcontroller, which digitises each quantity, converts the raw conversion result into engineering units using the scaling factors embedded in the firmware, and compares the result against threshold values held in the program. When a monitored quantity leaves its permitted band the microcontroller de-energises a relay through a Darlington driver stage and thereby disconnects the motor supply. The measured values are simultaneously written to a 16x2 liquid crystal display for local indication and uploaded over the on-board Wi-Fi interface to a ThingSpeak channel, where they are recorded as three separate fields and can be observed remotely from any browser. The complete circuit was fabricated on a single-sided printed circuit board using the screen-printing and etching route. The significance of the implementation lies in combining local threshold-based tripping with cloud-side visibility of the machine on a single low-cost embedded platform.