Abstract: Abstract:In the “11.5” accident of Togtoh Power Generation Company Limited, only one of four output transmission lines remained in normal operation. Meanwhile the unit No.8 was operating independently and shouldered important responsibility to provide auxiliary power for whole plant. The adjustment of boiler drum water level influences on unit safe operation directly, and the incorrect adjustment may cause accident of boiler fire extinction and unit shutdown. Taking the drum water level adjustment of unit No.8 in independent operation as example, the related problems were analyzed, and the relevant adjustment measures were given.

Key words: Key words:transmission line tripping, output lines all tripped, independent operation, boiler drum water level, adjustment