Live Line Technology Distribution Line Lightning protection 3

Live Line Technology Distribution Line Lightning protection 3 kv≤ 33 kv ZETDC Zimbabwe Combi unit project Installations LIVE LINE TECHNOLOGY Presented by : - Kevin Risi March 2014 T (018) 468 5080 F (018) 468 3303

ZETDC Zimbabwe Electricity Supply Authority (ZETDC) 2

ZETDC Zimbabwe Electricity Supply Authority (ZETDC) ZESA 3

BEFORE Nyakudya Primary School Dombosawa Area Harare 4

BEFORE Nyakudya Primary School 1 x Transformer lost every year Fuse Problems : 1) Fuses are in front of the surge arrester 2) Multiple fuse blows and customer outages on site. 3) Leads to transformer failure. Surge arrester problems : 1) 11 kv surge arrestors are inferior quality. 2) No way of knowing when the are blown. 3) A blown transformer is the indication a surge arrester was previously blown. 4) Leads to transformer failure. 5

AFTER Nyakudya Primary School Dombosawa Area Harare 6

AFTER Fuses improved : Surge arresters improved : 1) Fuses are protected by the surge arrester. 2) Nuisance fuse blows eliminated 1) Surge arrester protects fuse. 2) Surge arrester alerts ZESA when blown/ spent. 3) It has a 2 min replacement from ground, with a link stick No losses have been Recorded since March 2014. 2 years savings. 7

AFTER Change the arrestor & fuse from ground Ø LLT Arrestor inserted upside dow Ø Easy insertion. Ø Hook & hinge exposed for easy 8 connection.

AFTER Eliminate fuse blows & save Xfr’s Prevention maintenance (level 4) Circuit diagram of the Combi Configuration Customer § Improved Service level. Surge Arrestor Fuse § Downtime eliminated. § Live Line capabilities. Combi Configuration § The surge arrestor is connected in parallel with the Fuse. § The surge arrestor protects both the fuse and transformer. § Nuisance fuse blows eliminated. § Transformer protection enhanced. Transformer 9

AFTER Ø Customer experiences better power quality. Ø ZESA improves income as customers are on line more often. Ø Reduction in nuisance power outages. Nuisance fuse blows are abated. Ø Safety is improved for the linesman, changing the arrester from ground. Ø Surge arrester is easily removed. Ø Maintenance is enforced and a pleasure to do. Ø Transformer lifespan improved. Ø Positive attitude of ZESA staff towards surge arrester replacement. Ø Return on investment is experienced in the first 1 -2 years. 10