Hi,
I have a question regarding meaning of "runaway speed" requirements specified for hydrogenerator sets. My doubt refers to the duration usually specified together with runaway speed value (eg. 200% of rated speed during 10 min.). I've never seen additional information about limitation of...
Our customer informed us about failure of cage motor, that was recently repaired in our workshop (630 kW, 6 kV, 50 Hz, 1500 rpm, TEFC). D-end bearing failure happened after ca. 6 weeks of continuous motor operation and – since the user did not apply remote vibration- nor temperature monitoring...
We recently carried out checking measurements on two HV cage motors (4000 HP) after their rewinding (VPI process). What surprised us, is that capacitance of stator winding insulation is very high – ca.100 times higher than in previously rewound motors of the same type. But all parameters taken...
