Division (2) Annex II is replaced by the following:

‘ANNEX II

Measurement methods

For the purpose of compliance with the requirements of this Regulation, measurements shall be made using a reliable, accurate and reproducible measurement procedure, which takes into account the generally recognised state of the art measurement methods, including methods set out in documents the reference numbers of which have been published for that purpose in the Official Journal of the European Union.

Calculation methods

The methodology for calculating the Peak Efficiency Index (PEI) for medium and large power transformers referred to in Tables I.4, I.5, I.7, I.8 and I.9 of Annex I is based on the ratio of the transmitted apparent power of a transformer minus the electrical losses to the transmitted apparent power of the transformer. The calculation of PEI shall use state-of-the-art methodology available in the latest version of the relevant harmonised standards for medium and large power transformers.

The formula to be used for the Peak Efficiency Index calculation is:

Where:

P₀

is the no load losses measured at rated voltage and rated frequency on the rated tap

P_c0

is the electrical power required by the cooling system for no load operation, derived from the type test measurements of the power taken by the fan and liquid pump motors (for ONAN and ONAN/ONAF cooling systems P_c0 is always zero)

P_ck (k_PEI)

is the electrical power required by the cooling system in addition to P_c0 to operate at k_PEI times the rated load. P_ck is a function of the load. P_ck (k_PEI) is derived from the type test measurements of the power taken by the fan and liquid pump motors (for ONAN cooling systems P_ck is always zero).

P_k

is the measured load loss at rated current and rated frequency on the rated tap corrected to the reference temperature

S_r

is the rated power of the transformer or autotransformer on which P_k is based

k_PEI

is the load factor at which Peak Efficiency Index occurs’;