Pursuant to Article 116 of the Energy Law

4.2.11.
 
P
ROTECTION
 
4.2.11.1. INTRODUCTION  
4.2.11.1.1. Connection Approval shall define the protection system of the facility being 
connected/ interconnected to the transmission system, as well as the obligations of JSC EMS 
and the transmission system user to obtain coordination of the protection system for the 
transmission purposes, both in the process of development planning and in the process of 
operational planning and transmission system usage. 
4.2.11.1.2. While choosing protection during the reconstruction of some bays in the facility, it 
is necessary to take into account the specificities of the installed equipment and in particular 
the conditions that the existing technical control system may require.
4.2.11.1.3. Protection should be designed to enable prompt and selective elimination of faults 
towards protecting the equipment transmission facilities and facilities of the transmission 
system users from permanent damage, i.e. to minimize the consequences of faults or irregular 
events in the transmission supply system and to maintain stable operation of the power 
transmission system. 
4.2.11.1.4. In order to ensure reliable operation of the protection it is mandatory for all 
protection systems to have appropriate reserve, remote or local. 
4.2.11.1.5. Protection devices are modern microprocessor based protection devices which in 
addition to protection function, have the capacity to perform:
- chronological recording of events at millisecond resolution ; 
- recordings of grid disturbances (fault recorder) and faults showing the operating 
parameters (current, voltage, frequency, etc. ) in millisecond resolution ; 
- self-supervision. 
4.2.11.1.6. Generally, at the voltage level of 110 kV in the facilities of the transmission 
system user and at the voltage levels of 110 kV, 220 kV and 400 kV relay protection and 
control device are installed as separate devices. At lower voltage levels, the use of combined 
protective and control devices is allowed. 
4.2.11.1.7. If the concept of protection requires communication of protection units from 
various facilities, the transmission system user should meet its obligations regulated by the 
act on connection/ interconnection relating to the said communication no later than 15 days 
before the commissioning of the facility (or part of the facility).