# Meters (Certification) Regulations (Northern Ireland) 1998, Paragraph 9: Margins of Error

Extent: N.I.

(1) The maximum error permitted for—
(a) single phase and polyphase whole current meters; and
(b) single phase and polyphase transformer operated meters when tested with transformers connected
shall not exceed plus or minus 1.5% for tests numbers 1, 2, 3 and 4 given in Table 2.
(2) The maximum error permitted for both single phase and polyphase transformer operated meters, when tested without transformers connected, shall not exceed plus or minus 1.0% for tests numbers 1, 2, 3 and 4 given in Table 2.
(3) The maximum error permitted for polyphase whole current and transformer operated meters, when tested with transformers connected, shall not exceed plus 1.7% or minus 2.7% for tests 5 and 6 given in Table 2.
(4) The maximum error permitted for polyphase transformer operated meters, when tested without transformers connected, shall not exceed plus 1.2% or minus 2.2% for test numbers 5 and 6 given in Table 2.
(5) Where current and voltage transformers, which are intended to be used with meters, are not tested connected to a meter then the total error of the transformers at any load point throughout the rated range shall not exceed 0.5%.

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Source: https://www.legislation.gov.uk/nisr/1998/444/schedule/1/paragraph/9 (the official version)
Page: https://openlegislation.uk/meters-certification-regulations-northern-ireland-1998/schedule-1/paragraph-9
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.