{"id":13304,"date":"2020-12-01T14:30:41","date_gmt":"2020-12-01T13:30:41","guid":{"rendered":"https:\/\/eneria.pl\/blog\/przeglady-techniczne-agregatow-do-przeznaczonych-pracy-awaryjnej-gwarancja-ponad-96-sprawnosci-urzadzenia\/"},"modified":"2024-10-04T14:42:47","modified_gmt":"2024-10-04T12:42:47","slug":"przeglady-techniczne-agregatow-do-przeznaczonych-pracy-awaryjnej-gwarancja-ponad-96-sprawnosci-urzadzenia","status":"publish","type":"post","link":"https:\/\/eneria.pl\/en\/blog\/przeglady-techniczne-agregatow-do-przeznaczonych-pracy-awaryjnej-gwarancja-ponad-96-sprawnosci-urzadzenia\/","title":{"rendered":"Technical inspections of power generators designed for emergency operation guarantee more than 96% efficiency of the device"},"content":{"rendered":"

Emergency power systems based on diesel-powered generator sets, or simply power generators, are installed in facilities where the loss of power mains would pose a threat to work or even to people’s lives or safety.<\/p>\n

Operating characteristics of the power generators<\/strong><\/h5>\n

Emergency generators are typically configured to start automatically after a power grid failure and provide the facility’s basic energy needs until grid power is restored. Although generators in areas with extremely poor power quality are capable of operating for up to 200 hours or more a year, in regions where power problems do not exist, these machines may not work at all. This is a significant departure from the continuous duty applications for which the motors in these units are typically designed. This variability in operational demand also creates challenges in determining the optimal maintenance and testing frequency for emergency devices with high-reliability requirements.
\nPeriodicity of maintenance has a significant impact on the reliability of a power generator.
\nIt is worth noting that by the general term “maintenance” I mean a combination of preventive maintenance (i.e., maintenance performed at regular intervals to reduce the failure rate), visual inspection and stress testing. A typical maintenance plan ranges from very simple items at set intervals, such as visual checks (e.g., to make sure vents and shutters are not blocked, check operating fluid levels, etc.), to more crucial items at longer intervals, such as replacing coolant or batteries. An important aspect of the annual maintenance plan is routine testing of the power generator.<\/p>\n

Testing power generators<\/strong><\/h5>\n

No-stress testing of a power generator involves starting the device, leaving it idling for a short time (usually 15 to 60 minutes), and then shutting it off. This checks the starting system, motor and some control system components, but this method does not stress the motor and does not test the transfer switch. No-stress tests pose little risk to the user, as test failure has a minor direct impact on the ongoing operation of the facility. Such a test is often conducted at weekly or biweekly intervals. Although manufacturers recommend weekly no-stress tests as one of the elements of proper operation, it is worth knowing that motor operation at low loads and low operating temperatures can result in the accumulation of unburned diesel fuel in the exhaust stack, high moisture content in the lubricating oil and other undesirable effects.
\nStress testing of emergency generators involves starting the unit and using a load bank to simulate the load. Stress testing guarantees a more accurate performance test than a no-stress test with similarly low risk, but does not check or test the power switch.
\nThe use of a load bank is often the most practical way to test a power generator. Eneria CAT recommends routine testing under an external load (using a load bank) especially when building loads at the generator’s site are low or unusable.
\nBuilding load tests of a generator include starting the device and transferring the facility’s load to an operating unit.
\nEneria CAT, as an authorised representative of the manufacturer in Poland, recommends that all generators subjected to regular no-stress testing be tested under load, even if not required by law.
\nThe typical load of a power generator set during normal operation should be maintained above 10% of the rated load for the newest units and above 30% of the rated load for older units (it is important to avoid damage caused by low-load operation).
\nThe goal of a properly implemented and designed maintenance plan depending on the type of power generator is the reliability of the device. This is especially important for critical power systems (e.g., Ministry of Defence facilities, banks, server rooms), where cost is a secondary concern, and for facilities where the cost of maintenance is small compared to the financial impact of power loss (shopping malls, server rooms, office buildings).<\/p>\n

Maintenance plans<\/strong><\/h5>\n

Inspections and checks do not limit the generator’s ability to start automatically, and even if units are shut down for worker safety while inspecting, for example, V-belts or replacing filters, service technicians are available to bring units back to operating condition immediately. As a result, response and repair times will be shorter for failures detected during testing, as technicians are on-site and able to begin corrective actions immediately.
\nThe fact is that diesel generators operating in emergency standby mode, with even a basic level of maintenance (limited to an annual inspection, and a visual inspection performed once every six months), have a much higher operational reliability than equipment without a maintenance plan.
\nIt has also been proven that common commercial maintenance plans (including those involving the user’s technical services) with weekly no-stress generator tests and monthly, bi-monthly or quarterly maintenance achieve an average annual reliability level higher than 96% for well-known units with typical operating hours. In addition, it should be demonstrated that locations with full-time professional staff and very intensive maintenance schedules can reduce the operational failure rate by another 66-80%, reaching a record-breaking rate of more than 99% annual operational availability for similar power generators.
\nInterestingly, new power generator sets are statistically less reliable than generator sets that have been in use for ten or more years. Power generators are expected to become more reliable as they age. This does not mean that generator sets should remain in operation indefinitely. Over time, the availability of spare parts decreases, and the repair itself carried out by qualified maintenance personnel will take longer than in the case of new generator sets. Nevertheless, exemplary use of the unit (including the use of a maintenance plan in accordance with the recommendations of the Eneria CAT service) will result in the long-term, reliable and trouble-free use of the generator set.<\/p>\n

Service life of power generators<\/strong><\/h5>\n

When it comes to extending the service life of generators with short total operating hours, potential replacement of the unit or obsolete auxiliary components may be the most optimal solution for some ageing equipment. This is especially the case with changing emission requirements or other local requirements.
\nIt is not uncommon for equipment owners to postpone preventive maintenance, deeming it too costly or time-consuming. However, this is often counterproductive. The cost of business operations related equipment failure during operation is often much higher and requires major emergency repairs. As a result, any savings from ignoring or delaying preventive maintenance quickly disappear.
\nEquipment failures can also increase the risk of incidents related to occupational health and safety issues. Maintenance plans are an important part of the Eneria CAT service because they support the continued operation of the power generator at the location of its installation, while also ensuring the safety of employees.
\nEneria CAT recommends that clients follow CAT\u00ae generator maintenance programmes in accordance with the highest standards designed specifically for the type of equipment and covering all critical features and functions of CAT\u00ae generators, including:<\/p>\n