# Commission Regulation (EU) 2017/1485 of 2 August 2017 establishing a guideline on electricity transmission system operation (Text with EEA relevance), Annex III

Extent: E+W+S+N.I.

Frequency quality defining parameters referred to in Article 127:
Table 1
Frequency quality defining parameters of the GB synchronous area
...
GB
...
...
standard frequency range
...
± 200 mHz
...
...
maximum instantaneous frequency deviation
...
800 mHz
...
...
maximum steady-state frequency deviation
...
500 mHz
...
...
time to recover frequency
...
1 minute
...
...
frequency recovery range
...
± 500 mHz
...
...
time to restore frequency
...
15 minutes
...
...
frequency restoration range
...
± 200 mHz
...
...
alert state trigger time
...
10 minutes
...
...
Frequency quality target parameters referred to in Article 127:
Table 2
Frequency quality target parameters of the GB synchronous area
...
GB
...
...
maximum number of minutes outside the standard frequency range
...
15 000
...
...

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Source: https://www.legislation.gov.uk/eur/2017/1485/annex/III (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-1485/annex-III
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.