A comparative analysis of prepayment meters on selected loads

Abstract

This paper presents a comparative analysis of measurement accuracy of single phase prepayment meters under different loads. This study was motivated by users complain on variations in metering from different energy meter models. The experimental method was adopted in this study.The experimental setup involved a digital stop watch, the developed meter and two specimensof existing commercial meters. These meters were connected to varying load under the same measurement conditions. The time taken to consume 0.01kWh in each load category for each meter was recorded. The measurement was carried out a number of times on a non-reactive load at 220V supply and results were analysed. The results obtained show that the claims of prepayment meters users may be correct as the commercial meters investigated do not have the same accuracy of load measurements. The null hypotheses of equal means and median on each load category were shown not to be correct as the statisticaltest results showed variations in sizes of hypothesis mean differences. There was also a relatively high degree of variation between the recorded measurements on the same load for each of the meters. The variation in the accuracy of load measurement results to an extra cost of up to ₦559.11 per month on average load of 320watts on the commercial meter studied.