Sectionalisers
Popular Links
Newsletter May 2010
Newsletter September 2008
ADVC Controller Range Video Now Available!
ADVC Controller Range Supports DNP over IP
Exhibition for a Smart Future
Sectionalisers
The RL-Series LBS can function as a sectionaliser when connected to a Nu-Lec controller. This means it can automatically isolate faulty sections of a network in conjunction with an upstream recloser. To accomplish this it senses the three-phase current and voltage to count the number of upstream recloser trip operations.
When the pre-programmed number of recloser operations is reached, the controller opens the sectionaliser during the dead time to isolate the downstream fault.
The logic of a sectionaliser network is best explained using the timing diagrams on this page. Using an example network where the recloser or substation breaker "F" is protecting a section of line containing sectionalisers "S1 and S2". S1 and S2 are programmed to open after three and two recloser trips respectively (SI = 3 and 2).
Different permanent faults located in section 1, section 2 and section 3 are described below.
![]() |
Fault in Section 1 (sect 1) The recloser "F" trips to lockout, remains Open (OFF) and the sectionalisers do not change state. |
![]() |
Fault in Section 2 (sect 2) When a fault occurs in section 2 the recloser trips and recloses twice and trips again before the sectionaliser "S1" opens to isolate the fault. The third reclose operation restores power up to "S1". The recloser "F" sequence resets after the sequence reset time. |
![]() |
Fault in Section 3 (sect 3) A fault in section 3 will cause the recloser to trip and reclose once and trips again before the sectionaliser "S2" opens to isolate the fault. Both sectionalisers count the interruptions. The second reclose restores power upstream of "S2". The sequence resets in the recloser "F" and "S1" after the sequence reset time. |



