The arrival of the electronics era, with its increasingly sophisticated technology, has led to a switchover from electromechanical meters to electronic meters. With their ability to read and store multiple data, and their many other functionalities, they are gaining in popularity, and both the utilities and manufacturers are shifting to electronic meters. Will this shift result in the extinction of Ferraris meters? It is interesting to debate this technical change.
The industry in India at present requires a considerable amount of interaction with the different state electricity boards within the country, and this has produced innumerable data for analysis and facilitation of decision-making. Recently the various utilities, manufacturers, testing institutions and consultants all over the country took part in a survey to determine the future of electromechanical meters. As the fate of 3-phase Ferraris meters needs a different decision-making process altogether, this topic was not discussed during the survey exercise. Instead the discussions and survey questions focused on the issues related to single-phase Ferraris meters only. A brief summary of the information shared by respondents, and the decisions arrived at during the discussions, may be of interest.
NUMBER OF METERS INSTALLED
The installed base in India for electromechanical meters is estimated to be 120 million – about 75% of the total installed base. The figures for electronic meters, however, were not so clear, with the estimate given by respondents varying from 50,000 to 1.9 million, with an average figure of 800,000 being accepted.
It emerged during the discussions that total clarity in the industry on the average number of meters purchased or sold is not presently available. Respondents agreed that the important factors for choosing meters were:
• Reliability of measurement
• Long life
• Extra features/functionalities
• Initial cost
• Commercial facilities, which include delivery and payment.
Feedback from several major Indian utilities showed that some 29% of them believe that electromechanical meters are reliable. About 16% indicated that these meters are not reliable, with 45% saying they are less reliable than electronic meters.
Although electronic meters are not widely used in the country at present for single-phase application, 48% of respondents indicated they believe these meters are reliable, with 32% suggesting they are very reliable. Very few respondents voiced any doubts about the reliability of electronic meters.
LIFE EXPECTANCY AND MAINTENANCE
Many questions were asked in respect of life expectancy and maintenance costs. Most of the respondents indicated that electronic meters score over their electromechanical counterparts to some degree. As far as initial cost was concerned, more than 70% indicated that this is low for electromechanical meters, and around 60% said that the initial cost of electronic meters is high.
While several respondents indicated that themaintenance cost for electromechanical meters is low, 60% said that these costs are high when compared to electronic meters.
The manufacturers of both electromechanical and electronic meters in India discussed existing manufacturing facilities, quality, back-up service and investment in research and development (R&D) in detail. The responses given by manufacturers suggest that as far as manufacturing facilities are concerned, the industry in India is on a par with many manufacturers in other countries. The general opinion with regards to quality is that the electromechanical meter industry suffers quality inputs, while the electronic meter industry has gained momentum and the infrastructure and facilities are up-to-date.
As far as back-up service and R&D facilities are concerned, the response for electromechanical meters is not that encouraging. Things are, however, looking better in the case of electronic meters, and the option to return the meter to the factory to analyse the reason for its malfunctioning was mentioned in particular.
Because of the maturity of the product, electromechanical meter manufacturers have adequate R & D facilities, whereas electronic meter manufacturers are dependent on institutions in India such as NPL, CPRI, NTH and ERDA, as well as Kema in the Netherlands, for international assessment and certification.
MOST IMPORTANT FEATURES
There was considerable discussion by both utilities and manufacturers on what constituted the most important features of electronic meters. They finally agreed that the three most important features are:
• Accuracy and sustainability of calibration
• Ability to read more complex data.
Two other features were also regarded as extremely important – ease of installation/maintenance and AMR capability. During the discussions with utilities, they also gave equal weight to provision of a prepayment facility, and complex data measurement. In order to obtain some more specific views on particular issues, additional questions were posed to a cross-section of respondents. The questions were based on the following factors:
• Replacement of electronic meters.
• Scope for adding extended life to electromechanical meters.
• The ageing factor.
• Standardisation of specifications.
EXTENDING METER LIFE
With regards to the life of electromechanical meters, the question focused on whether new features like AMR and tamper detection could be added to the meters in an effort to extend their life. The response to this question was that addon features may still not duplicate the higher accuracy, low wear and tear and tamper prevention features of electronic meters.
While discussing the same subject, useful suggestions emerged from a cross-section of utilities, to the effect that by ensuring high quality in-house testing and the adoption of quality assurance for both materials and processes used in the manufacture of these meters, there could be considerable improvement in the quality of electromechanical meters produced in the future.
We also posed a question about the slow running of older electromechanical meters. The response indicated that wear and tear of jewels, enlargement of PTFE bushes employed in magnetic bearings, and ingress of dust and moisture all had a detrimental influence on the life and operation of these meters.
With regards to standardisation of purchase specifications, we received some suggestions on counters (registers both impulse and steppermotor driven), NVM and running of the meter in the event of reversal of the CT terminal.
There were also suggestions that the code of conduct of connection needed to be standardised, and some respondents made some suggestions regarding hardware standardisation.
By far the majority of suggestions had to do with the problem of meter tampering, however. Respondents said that electronic meters provide solutions to the tampering problem only if:
• They are immune to external influences.
• Steps are taken for usage of proper shielding of transformers used in power supply.
• The latest developments in electronic technology, such as SMT, ASICS based on VLSI technology and compact component packages are used.
• The electronic meter is of good quality, with proper logic for sensing tampering conditions.
In addition we posed a question to a cross-section of the electromechanical meter industry to make some projections for the next five years and ten years. (See figures 1 and 2).
This article offers a glimpse of the change in philosophy in the Indian metering market as electromechanical meters slowly give way to their electronic counterparts. Meters are vitally important as a cash box and revenue earning device for utilities, and our survey showed that accuracy and reliability at an economical cost form the criteria for selection of a particular meter and meter type.
Today the shift to electronic meters in India is of the order of 15-25%, and this is likely to increase gradually as utilities consider the benefits of the new technology – and as the cost of electronic meters gradually falls over time.
1] Discussions with state electricity boards, manufacturers, testing agencies.
2] Publication from IEEMA.
3] Indian meter industry panorama – an overview paper presented at national symposiums.