Maximising asset reliability
Mark Meyer - Product Manager, PowerDB
Brad Perry - National Sales Manager, PowerDB
Regular maintenance on a fixed schedule is the key to ensuring that assets operate reliably. At least that’s the traditional view and it’s a view that might have been justified in the days when the true condition of many types of assets could only be determined by dismantling them. But in today’s world, the shortcomings of regular maintenance carried out at fixed intervals are too great to ignore, especially as modern technology makes possible a much more efficient and cost- effective approach.
But what are the shortcomings of fixed-interval maintenance? The biggest is unnecessary expenditure – maintenance work is carried out on the asset whether it’s needed or not, and in many cases it’s not needed, because the maintenance intervals have to be set based on worst-case scenarios. Unnecessary costs escalate further if the maintenance program includes automatic replacements of assets that have reached the end of their nominal service lives, as many of these will be perfectly capable of giving further service.
All of that being said, it’s also true that studies have shown that the most frequent causes of asset failure relate to poor or inadequate maintenance. So what’s the solution? The answer is to replace routine maintenance carried out at regular intervals with maintenance carried out only when needed and as determined by a carefully structured program of testing. Modern test equipment and techniques allow the condition of almost every type of asset to be accurately assessed without the need for dismantling or long periods out of service, so this is a much more effective and much less costly option.
Routine testing will form a major part of the program, especially for assets that are already in service, but the program will also include acceptance testing for new assets and pre-service tests for assets that have undergone repair. And there will inevitably be a need from time to time for diagnostic testing to determine the cause of the problem when an asset is not performing correctly.
The testing program will be designed to ensure that, as far as possible, incipient faults are detected before they progress to failures and that assets are replaced when they have genuinely reached the end of their useful service lives, whether or not this coincides with the end of their nominal service lives. As well as the type of asset under consideration, the formulation of the testing program will take into account the criticality of the asset, the criticality of its function, and its operating conditions. Critical assets operating in severe conditions will, for example, be scheduled for the most frequent testing.
This approach to maximising asset reliability clearly has a lot to recommend it but there are challenges to its implementation. Many of these relate to the data produced by regular testing. First of all, there’s a lot of it, especially in a large organisation like a power utility, so just collecting, recording and storing it can be problematic. Then there’s the needle-in-the-haystack effect: when a large amount of test data is available, it’s very difficult to spot the occasional unexpected result that may well be indicative of a problem. Analysing and reporting on the mountain of data and providing easy access to specific sets of data when they’re needed – for example, when comparing a new result with historic results for the same asset – are other challenges.
It is with all of this in mind that Megger has developed PowerDB, an asset and test data management system that’s specifically designed to make life easier for engineers and technicians working with electrical power systems and also to help users maximise the reliability of their assets while minimising lifetime costs.
A key feature of this versatile software package is that it runs on a readily available platform – a modestly specified PC with a recent version of Microsoft Windows is all that’s needed – and that it can easily import data from a wide variety of sources, including direct from many Megger instruments, for which it provides a simple and consistent user interface. It can also acquire data from selected third-party test sets and import existing test data in many popular formats, a feature that is particularly useful for adding historical data. Data can also be entered manually.
Once captured by PowerDB, test data is stored in a database, and the databases from multiple devices running PowerDB can be synchronised into a single central database for added security and to ensure wider accessibility. It is even possible to merge data imports from other sources – such as external databases – to aid analysis and trending.
The capabilities of PowerDB, however, go far beyond simply collecting, organising and storing data, although these are the central elements of its functionality. Three key requirements for an effective program of regular testing are scheduling, consistency and documentation. PowerDB facilitates all of these. It supports, for example, automatic generation of work orders for testing based on asset maintenance periods and features extensive job listing with powerful filtering options for easy retrieval.
To help ensure consistency in work practices and reports, and to provide an intuitive user interface, PowerDB makes extensive use of forms for data entry, data display and for producing printed reports. An important benefit is that the data entry screens are exactly the same as the printed reports, which greatly simplifies interpretation of the test results. Close to 400 predefined test forms are provided in PowerDB covering many types of electrical apparatus such as bushings, batteries, cables, generators, transformers, relays and motors.
These forms can be used as they stand, or users can easily customise them to suit their own particular requirements. Users can also design new forms from scratch if they have special requirements for which no similar form is available. No matter how the forms are generated, their use enforces a high degree of standardisation on the test procedure and the recording of results, thereby achieving the consistency that is essential if the full benefits are to be gained from routine testing.
PowerDB can also help with scheduling and compliance. The optional compliance view makes it easy to monitor compliance with NERC-mandated testing schedules or simply to track regular testing of assets or groups of assets. Users can create compliance categories and sub-categories and assign these to individual assets or groups. Powerful filtering capabilities then make it a simple task to determine the compliance or maintenance status of these assets or groups. The display screen for the compliance view includes a colour-coded calendar that provides an at-a-glance overview of asset status. The default colours are green for compliant, yellow for a warning period and red for non-compliant.
Another PowerDB option is an alert notification system, or alert manager, will automatically send email or text messages to pre-defined recipients when any time or activity threshold has been reached, based on the information held in the master database. This facility can be used, for example, to produce a reminder when an asset is becoming due for maintenance. The alert manager can also be configured to create notifications for database entries that reveal deficiencies, invalid compliance status, out-of-limit test values and any other situation that can be determined from the data held in the database.
Versatile data trending and analysis functions are further key features of PowerDB. Trending can be performed on the fly while tests are being carried out. This offers a convenient and efficient way of comparing new readings with historical values and with results from similar assets. Statistical information is produced which aids the evaluation of test results and, therefore, assessment of the condition of the asset under test.
A wide range of analytical functions are available for processing test results. These include the generation of an asset ‘health index’ based on information acquired from multiple tests, and failure studies that can provide revealing insights into the failure rates for a population of assets. The intuitive PowerDB data query tool can be used to extract data from the database and present it in a format that is optimised for use in further studies or for processing by third-party diagnostic software.
PowerDB can be configured to pass data to other computerised maintenance management systems (CMMSs) and to generate comprehensive documentation including, for example, cover pages, table of contents, comment and deficiency summaries, test forms populated with test results and field service reports. This documentation, which can be printed or saved in the form of Adobe Acrobat pdf files for easy electronic storage and transmission, is an exceptionally useful aid for planning future activities and schedules.
Even though it offers wide-ranging functionality, PowerDB is intuitive in operation and easy to use. As has already been mentioned, it uses exactly the same forms for data capture and for producing reports, and there is a high level of uniformity across different applications.
The simplicity and convenience of the standard user interface can be further enhanced with the optional dashboard add-on, which is a web-based portal that gives access to the data in the master database. The dashboard can be viewed using almost any standard internet browser running on a PC, a tablet or even a smartphone and it opens with a summary view of activities, including statistics about data entry and usage. Users can then search and review entries in the database, which are presented in forms which are identical with those used elsewhere in the program.
Carefully planned testing is undoubtedly the surest route to maximising asset reliability, but it is only effective if the tests are carried out on schedule using prescribed procedures, and the results are properly organised, stored, analysed and reported. These requirements might seem onerous, but PowerDB, a powerful software package designed specifically to meet the needs of the electrical power sector, provides a complete and cost-effective solution. To put it in a nutshell, a modest investment in software unlocks big gains in asset reliability which, in turn, means money saved and disruption eliminated.