Generator engine oil replacement strategy
WST04
The technology has existed for many years to determine the quality of standby generator engine oil. Despite this many organizations still employ a fixed time schedule for oil replacement.
Engines are designed to operate in harsh environments, from onboard ships to in mining applications, they are designed to work hard. At the other end of spectrum, in many buildings the standby generators rarely run, clocking up more hours for routine testing than they ever do for real outages. They are often kept in near ideal conditions, indoors, in a stable temperature, in a clean environment.
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Why does oil need changing?
As oil ages it oxidizes, the process of oxidation is naturally occurring, but the rate at which this happens depends on a number of factors:
Temperature – the higher the temperature, the shorter the oil life. Based on the Arhenius Rule, for every 10°C increase in temperature above 40°C, the oil life is halved.
Moisture – the more water present the faster the oxidation rate
Oxygen – the more oxygen from splashing induced by low oil levels the faster the oxidation rate
Catalytic reactions – most typically from copper and other wear debris particles
The condition of the engine – ring wear, fuelling etc
Oil quality - The quality of the base stock oil in terms of the levels of impurities
The quality of the additive pack in terms of the anti-oxidants available to slow down the oxidation rate of the oil.
Given the amount of variables that exist it is impossible to define a suitable fixed frequency, as you can imagine to avoid liabilities manufacturers will recommend an oil change interval based around worst case scenarios with significant margin factored in.
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A range of options exist for adopting a condition based replacement programme, your generator service vendor is well placed to advise you on your options. These may range from site based kits, where site technicians take a periodic sample, through to samples extracted and sent away to a laboratory for analysis. the intelligence gained from this testing will inform a condition based replacement regime which will likely result in a reduction of waste.
The quality of the additive pack in terms of the anti-oxidants available to slow down the oxidation rate of the oil.
