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