Live Line Technology Distribution Line Lightning protection 3
Live Line Technology Distribution Line Lightning protection 3 kv≤ 33 kv BPC Sub-station Combi unit pilot project Transformer Combi Unit (Transformer Protection) Live Line Arrestor (Firewall) LIVE LINE TECHNOLOGY Presented by : - Kevin Risi September 2013 T (018) 468 3344 F (018) 468 3303
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BEFORE Mmanako 33 kv/11 kv Substation. 3
BEFORE -Mmnoko 33 kv/11 kv Substation • 3 x Transformer losses recorded in one calender year. • A 500 kva transformer costs BPC Namibian P 200 000 per unit. • The transformer site is 30 km from Gaborone. Callout costs include, petrol and labour costs to the same site, three times within a 12 month period • Multiple nuisance fuse blows have been recorded. • Surge arrestors cannot be replaced quickly with a link stick. No sure method of knowing when the surge arrestor is expired. • Earths are being stolen. 4
BEFORE 3 x Transformers were lost here in a Calendar year in 2012/2013. Problems : 1) No 11 kv surge arrestors present Problems : 1) Stolen earths. 2) Surge arrestors not effective. 5
AFTER Improvements : 1) Installed 11 kv Firewalls 2) Installed & secured earths Improvements : 1) Installed 33 kv Firewalls. 2) Installed 33 kv Combi units. 3) Installed & secured earths 6
AFTER Improvements : 1) The earths are installed in steel conduits behind steel channels. 2) Cement in the ground. 3) Steel channels are 0. 5 m into the ground and 2 m up the pole. 7
BEFORE – Kumakwane 33 kv/11 kv Substation. 8
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AFTER 10
-Trf 1 Koro – Trf/DB 1 • 14 August 2013, Combi units were installed. AFTER • The surge arrestor in the Combi unit will alert Nored when blown. • The surge arrestor protects the fuse link and transformer. • The surge arrestor is in parallel with the fuse. • Surge arrestors on tank removed. 11
-Trf 1 Koro – Trf/DB 1 • The surge arrestor can be replaced with a link stick within a few seconds. AFTER • The surge arrestor reduces lightning induced nuisance fuse blows by 100% • Surge arrestors on transformer casing removed. • Fuse links one pole away are removed. 12
AFTER -Trf 1 Koro – Trf/DB 1 • 2 x 35 mm Earths are connected between the Combi unit and onto the earth point of the transformer body. 13
-Trf 1 Koro – Trf/DB 1 AFTER • The Combi unit houses both the fuse and surge arrestor. • The Combi unit is perfect for remote locations. • The surge arrestor alerts you by dropping out when it needs replacing. • The fuse links are removed one pole away. 14
AFTER -Trf 1 Koro – Trf/DB 1 The Combi unit was specially designed to protect transformers. Transformers will never need to be replaced, because when surge arrestors are replaced on time, exactly when they expire, protection on the Transformer is guaranteed. 15
The end 16
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