Pursuant to Article 116 of the Energy Law

4.2.4.
F
REQUENCY 
 
4.2.4.1. The facility has to be designed and constructed for permanent operation within 
frequency range 49.5-50.5 Hz. 
4.2.4.2. In case frequency is outside the proscribed range, the facility of transmission system 
user stays connected to the transmission grid for the time period which depends on the size of 
frequency deviation, and according to the following conditions: 
- For the generation units in accordance with the point 4.3.8.1.1. 
- For the facilities of end users and distribution facilities for time period which is 
50% longer than time related to the generation units for the same frequency 
deviation. 
4.2.4.3. The section 4.2.4. does not refer to disconnection of facilities due to sub frequency 
protection. 
4.2.5.
 
THE
 
DEVICE
 
FOR
 
BREAKER
 
ON/OFF
 
CONTROL 
4.2.5.1. Should power and voltage calculations show that some difficulties are to be expected 
when switching the breaker on in the facility of transmission system user, the JSC EMS may 
request installation of a device to control the breaker switch-on in this facility. This device 
should be adjusted according to the following switch-on synchronisation parameters: 
- max difference of the voltage: 

U
max
= 15%U
n
; 
- max phase difference between voltages:

max
= 30

; 
- max frequency difference: 

f
max
= 0,5 Hz. 
4.2.5.2. The device for breaker switch-on should have options for reading synchronization 
parameters of switch-on. 
4.2.6.
 
REACTIVE