supply of class b & c surge protection device (spd)class b & c surge protection device (spd),supply of class b & c surge protection device (spd) -type i & ii with visual indication and po tential free contact to remote monitoring as per specification no. rdso/spn/165/2012 ver 3.0 or latest and iec standard 61643 for single line 230v ac application with handling lightning surges of 10/350 microseco nds and switching surges of 8/20 microseconds .one set consists of 3 nos. of spd (2 no. of b class (l-n, n-e ) and one no. of c class (l-n) all enclosed in a box with kema or vde certified as per latest iec 61643-11-2 011 standard. class b &c surge protection device required with three modules only. installation of class b & c surge protection device should be as per the tan no:- sts/e/tan/3006, version- 3.0 ; dated:- 08.01.20 25 (tan specs attached as annexure.) [ warranty period: 30 months after the date of delivery ] ]