NRB Disconnector for outdoor installation Rated voltage: Rated current: 12 72, 5 kv 1250 2500 A Several erection alternatives Simple structure, easy to install Self cleaning contacts with magnetic locking All steel parts hot dip galvanized Designed and tested according to IEC 129 ABB Avangard AD
DESCRIPTION The disconnector type NRB consists of separate poles, which can be arranged for single pole operation or linked together by operating rods to form 2- or 3-pole units. Each disconnector pole consists of base frame with bearings, three post insulators (two fixed and one rotating), current carrying paths with contacts and terminals. BASE FRAME The base frame consists of a U - beam N12 with four fixing holes. The fixed insulators are erected at the outer ends of the U-beam. The rotating insulator is erected on a bearing in the centre of the U-beam. CURRENT CARRYING PATHS WITH CONTACTS AND TERMINALS The current carrying paths consist of a horizontal aluminum bar painted red, in the middle bolted to the rotating centre insulator and fitted with spring loaded copper contacts at both ends. When the disconnector is closed the contacts grip a contact bar. The contacts are fitted with magnetic locks which increase the contact pressure in the event of a short circuit. The terminals consist of aluminium plates bolted to the fixed insulators. Via a bimetalic strip they also provide a mounting point for the fixed contacts. Disconnectors for rated current 1250A will at delivery be supplied with bimetallic strips which allow connection to aluminium as well as copper cables. OPERATION The disconnectors are operated by rotating the vertical operating shaft 190º by means of a suitable operating mechanism. Two kinds of operating mechanisms are available, either a manual operating mechanism or a motor driven operating mechanism. EARTHING SWITCHES The three pole disconnector can, if so desired, be fitted with earthing switches, operated by eather a manual or motor operating mechanism as described above. The earthing switches should always be provided with mechanical interlocking to prevent incorrect operation. ERECTION ALTERNATIVES Disconnector type NRB / is designed in three erection alternatives horizontal parallel erection, horizontal row erection and vertical parallel erection.
Electrical parameters Rated values type NRB Rated voltage kv 12 / 1250 12-12 24 / 1250 20-24 36 / 1250 30-36 52 / 1250 45-52 72,5 / 1250 60 72,5 12 / 2500 10-12 24 / 2500 20-24 36 / 2500 30-36 52 / 2500 45-52 Rated current A Rated short circuit making current ka peak Rated short circuit breaking current 1s k A 1250 79 31,5 2500 79 31,5 Rated and withstand voltages Withstand voltage Rated voltage kv Switching impulse withstand voltage 1.2/50 µs between open to earth and between contacts poles, kv kv Power withstand voltage 50 Hz - 1 min to earth and between open between poles, contacts, kv kv 10-12 95 110 35 45 20-24 150 175 55 75 30-36 200 230 75 100 45-52 250 290 105 145 60 72,5 325 375 140 190 Isolators Rated voltage kv Creapage distance, mm 12 280 5.0 24 540 6.5 36 750 10.3 52 888 11.3 72,5 1350 20 Gross weigth,kg Earthing Fig.А Disconnector type NRB 12-72,5/1250 horisontal parallel mounting Fixed holes for mount to the support structure
Disconnector type NRB 12 72,5 / 1250 (fig.а) Type NRB А А1 А2 А3 А4 В С Е Е1 F F1 F2 R 12/1250 430 150 140 55 365 120 70 690 825 650 330 540 240 24/1250 530 245 155 55 465 120 70 660 825 650 330 540 240 36/1250 650 365 155 55 585 120 70 860 985 810 490 700 320 52/1250 735 430 165 55 670 120 70 960 1085 910 590 800 370 72,5/1250 980 650 180 60 915 140 90 1205 1335 1160 840 1050 495 Disconnector type NRB 12 72,5 / 2500 (fig.в) Type NRB А А1 А2 А3 А4 В С Е Е1 F F1 F2 R 12/2500 480 150 140 55 365 120 70 690 915 650 330 540 240 24/2500 580 245 155 55 465 120 70 660 915 650 330 540 240 36/2500 705 365 160 60 590 140 90 860 1075 810 490 700 320 52/2500 790 430 170 60 675 140 90 960 1175 910 590 800 370 L3( 11/4 ) Fig.С Disconnector type NRB with earthing blades horizontal parallel mounting Mechanical lock Earthing L3 Operating mechanism mounted on disconnector pole one Support beam Fixed holes for mounting to the support structure Operating mechanism mounted on extra support beam Fig.В Disconnector type NRB 12-75,5/2500 horizontal parallel mounting
Disconnector type NRB with earthing switches Horizontal parallel erection (fig.с) Type NRB N min N1 min L3 L4 R3 12/1250 530 300 2L1+290 L2+L3 265 24/1250 530 300 2L1+290 L2+L3 365 36/1250 690 300 2L1+290 L2+L3 485 52/1250 790 300 2L1+290 L2+L3 570 72,5/1250 1040 400 2L1+290 L2+L3 810 12/2500 530 300 2L1+290 L2+L3 265 24/2500 530 300 2L1+290 L2+L3 365 36/2500 690 400 2L1+290 L2+L3 485 52/2500 790 400 2L1+290 L2+L3 570 Mechanical lock Disconnector type NRB with earting switches Horizontal line erection (fig.d) Type NRB N min N1 min L3 R3 12/1250 1100 395 2L1+290 265 24/1250 1250 395 2L1+290 365 36/1250 1550 475 2L1+290 485 52/1250 1750 525 2L1+290 570 72,5/1250 2200 650 2L1+290 810 12/2500 1200 395 2L1+290 265 24/2500 1350 395 2L1+290 365 36/2500 1650 475 2L1+290 485 52/2500 1850 525 2L1+290 570 Fig.D Disconnector type NRB 12-75,5/ 1250 horizontal line erection
Mechanical lock Disconnector type NRB with earthing blades vertical parallel mounting (fig.е) Type NRB N min L3 R3 12/1250 530 2L1+290 265 24/1250 530 2L1+290 365 36/1250 690 2L1+290 485 52/1250 790 2L1+290 570 72,5/1250 1040 2L1+290 810 12/2500 530 2L1+290 265 24/2500 530 2L1+290 365 36/2500 690 2L1+290 485 52/2500 790 2L1+290 570 Fig.Е Disconnector type NRB with earthing switches vertical We reserve the right to make changes in the course of technical development of the product. ABB Avangard AD 32 Nikola Petkov Str. 5400 Sevlievo, Bulgaria Tel.: +359 675 ; 3 36 20 ; 3 00 37 Fax: +359 675 3 00 43