supply of supply of class b&c surge protection device (spd) type i & iisupply of class b&c surge protection device (spd) type i & ii,supply of class b&c surge protection device (spd) type i & ii with visual indication and poten tial free contract to remote monitoring as per rdso spec no. rdso/spn/165/2012 version 3.0 or latest and iec standard 61643 for signals line 230 v ac application with handling lightning surges of 10/350 microseconds and switching surges of 8/20 microseconds. one set consists of 3 nos. of spd (two nos. 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 61643-11-2011 standard class b&c surge protection device required with three modules only as per attach ed technical specification ( annexure 1). spd shall be of make obo, phonix or equivalent. [ warranty pe riod: 30 months after the date of delivery ] ]