Knowing the correct ampacity as prescribed by the specifications of the Philippine Electrical Code is important as this ensures that electrical wiring installations are designed with safety considerations. However, there is no device that accurately measures electrical wires current carrying capacity or ampacity. To address the problem, this project study designed a prototype device called ampacity meter for use in the Electrical Engineering laboratory. The device consisted of two parts: first, there was a VARIAC or the variable AC source to produce a current that would be injected into the wire. Since the current from the VARIAC is small, there was also a current transformer to step up the current. In determining the current carrying capacity of the wire, the temperature was measured by a temperature sensor or a thermistor during the injection of the current; and second, the ammeter that displayed the current carrying capacity of electrical wire or its ampacity.
The series of experiments done showed that the prototype device was able to measure the ampacity of TW and THHN electrical wires in various sizes. Because a more accurate reading of the temperature of the current flowing into the wires is needed, recommendations included modifications on the design of the device controlling ambient temperatures including a built-in ammeter or a microchip-controlled LCD display for future prototypes.