Question 428Motor Plants - Assistant Engineer

The correct answer is D) normal operating temperature without a load. The reasoning is that adjustments to the compensating needle valve in a hydraulic governor should be made with the engine at normal operating temperature without a load. This allows the governor to be properly calibrated and adjusted without the additional influences of high load or speed conditions, which could lead to inaccurate adjustments. The other options are incorrect because adjusting the governor at maximum power (A and B) or half speed (C) would not provide the ideal conditions for proper calibration and adjustment of the compensating needle valve.