Epoxy resin rich system for electrical machines

Bharat Heavy Electricals Limited, INDIA manufactures among its diversified products Turbogenerators of rating 2.5 MW to 500 MW & other Electrical machines like AC/DC motors, Synchronous Condensers etc. at 3 of its Major manufacturing Divisions at Hyderabad, Hardwar and Bhopal. The foundation towards improved and reliable insulation system was laid in B.H.E.L., when the first "Epoxy Resin Rich Paper Tape Insulated Bar of 60 MW, 11 KV Turbogenerator was ejected out of the mould after curing, in year 1966 in Hyderabad plant of BHEL, Considering the superiority of this Insulation system in a span of 6 years the other electrical machines manufacturing units of BHEL at Hardwar and Bhopal switchedover to this system of Insulation for stators of Electrical machines from their conventional bituminastic insulation systems being followed earlier. The paper briefly describes the experiences of BHEL with this insulation system, in a span of 16 years relating to material improvements, Quality norms, Process and tooling improvements and other measures taken for stabilisation of this system, Highlighted in the paper are some of the site problems encountered by BHEL with this Insulation in operation and Remedial measures taken for elimination of the same in Design & Manufacture.