Consideration of EP-additives
It is known that some EP additives in the lubricant can extend bearing service life where lubrication might otherwise be poor, e.g. when κ < 1 and if the factor for contamination ηc > 0,2, according to DIN ISO 281 Addendum 1:2003, a value of κ = 1 can be used in the calculation if a lubricant with proven effective EP additives is used. In this case the life modification factor aSKF has to be limited to ≤ 3, but not less than aSKF for normal lubricants.
For the remaining range, the life modification factor aSKF can be determined using the actual κ of the application. In case of severe contamination, i.e. contamination factor ηc < 0,2, the possible benefit of an EP additive has to be proved by testing. Reference should also be made to the information about EP additives presented in the section Load carrying ability, EP and AW additives.