Proceedings Summer 2016
Prepared by NMC Engineering
1. Large machines undergoing a resistance insulation testing using a megohmmeter should be discharged to remove
any accumulated electrostatic/capacitive charge stored. When should this discharge be performed?
A. prior to conducting the insulation resistance check only
B. while performing the insulation resistance check only
C. after conducting the insulation resistance check only
D. prior to and after conducting the insulation resistance check
2. The pump packing gland has been repeatedly tightened by small increments until the gland has bottomed. Which
of the actions listed should be carried out next if the leakage continues to be excessive?
A. Replace all of the packing.
B. Replace with larger cross-sectional turns of packing.
C. Replace soft packing with packing turns that are covered with lead wrap.
D. Continue to add more turns of packing.
3. In a medium-speed marine propulsion engine equipped with direct admission air starting valves, the cylinders
without air starting valves fire first because the .
A. operation is under higher compression
B. fuel is admitted only to these cylinders during cranking
C. compression is released during starting by opening the exhaust valve
D. cylinders are not chilled by the expansion of the starting air
4. The most troublesome corrosive substances in boiler water are oxygen and .
A. hydrogen sulfide
B. sulfur dioxide
C. carbon dioxide