... per IECPVC Insulation: Type A of IEC (General purpose) (1) Single Core. (2) Twin, Three, Four (Circular) ... filled, where necessary, with suitable material PVC sheath ST-1 of IS: 5831 (General purpose). For Flat Twin ... the same plan. Colour for Core identification & colour sequence: (1) Single Core - Red, Black, Yellow or Blue. (2) ... of Insulation(mm)(mm)(mm)*1.01/1.130.7*1.03/0.650.71.51/1.380.71.53/0. ...