BS EN IEC 60255-181:2019 Measuring relays and protection equipment Functional requirements for frequency protection

Electrical testing
Electric power system disturbances
Voltage fluctuations
Switchgear
Surge protection
Type testing
Electric power systems
Relays
Electrical protection equipment
Surges (electrical)
Switches

Link: BS EN IEC 60255-181:2019 Measuring relays and protection equipment Functional requirements for frequency protection
Source: BSI Standards