Question 661Steam Plants - Assistant Engineer

The correct answer is C) check the lube oil temperature. The most practical method of determining the condition of a shaft bearing while the shaft is in operation is to check the lube oil temperature. This is because an increase in bearing temperature is an early indicator of bearing wear or damage. Monitoring the lube oil temperature provides a direct and real-time assessment of the bearing's condition without interrupting the operation of the shaft. The other options are not as practical or effective for this purpose. Option A, performing a carbon blot test, requires taking an oil sample and analyzing it, which is more time-consuming and does not provide immediate feedback. Option B, checking the lube oil viscosity, is not as sensitive an indicator of bearing condition as temperature. Option D, visually inspecting the bearing, is not possible without disassembling the machinery, which would require shutting down the shaft.