The master's thesis deals with the development of a three-phase adapter which can be used in combination with portable appliance tester and machinery tester instruments. A portable appliance tester is an instrument, which is intended for periodic inspection after repair, modification or upgrades of a portable appliance in accordance with the standard DIN VDE 0701-0702. Machinery tester is an instrument used for testing the safety of larger machinery, which is not manually portable while it is running. The tests are performed according to standards EN 60204-1 and EN 61439-1. The three-phase adapter enables the expansion of both main instruments with the purpose of easier and faster testing of machinery or portable appliances which are connected to the mains supply via a plug. This extension also adds an option for test-ing the arc welding equipment according to the standard IEC 60974-4. Additionally, it enables the testing of one-phase and three-phase PRCDs and cable extensions for portable appliances and electric vehicles.
This thesis describes in detail the measurements performed by one of the main instruments in collaboration with a three-phase adapter. These are: measuring the resistance of the PE conductor, measuring the insulation resistance, testing the operation of the RCD and measuring the residual voltage. Results that the three-phase adapter measures independently are also exhaustively described, such as the follow-ing three-phase and single-phase load values: voltage and current including THD and frequency, apparent, reactive and real power including the power factor, leakage current measured via voltage drop on the resistor and with the differential method.
Finally, the results measured in the laboratory by the newly developed three-phase adapter are compared to the ones measured with the reference instruments. The three-phase adapter has to be calibrated before being sent to the final user and its faultless operation must also be checked. During the development, care was also taken of components for automatic calibration and final control, because the manual implementation of these procedures would be quite time-consuming.
|