FDNY Z-51- REFRIGERATION LUBRICANTS EXAM QUESTION AND VERIFIED ANSWERS LATEST UPDATE

FDNY Z-51- REFRIGERATION LUBRICANTS EXAM QUESTION AND VERIFIED ANSWERS LATEST UPDATE compressor lubrication - ANSWER an adequate supply of oil must be maintained in the crankcase of a refrigeration compressor at all time to ensure continuous circulate properly through a system with refrigerant - ANSWER refrigeration lubricants must have certain properties in order to be able to flow in low temps, withstand high temps and remain harmless to refrigerants and equipment, travel freely through all parts of the system, and be free of moisture - ANSWER refrigerant lubricants must type of refrigerant, operating temps in the system, properties of the lubricant - ANSWER lubricants effectiveness is determined by low wax content, high thermal and chemical stability, and a low pour point and low viscosity - ANSWER a good lubricant has animal, vegetable, mineral, synthetic - ANSWER lubricants can be classified as naphthenic, paraffinic, aromatic - ANSWER mineral oils can be grouped as naphthalene - ANSWER crystalline aromatic hydrocarbon usually obtained by distillation of coal tar or petroleum crude oil parrafin - ANSWER waxy crystalline flammable substance obtained from distillates of wood, coal, petroleum, or shale oil use chiefly in coating and sealing, candles, rubber compounding, and in pharmaceutical and cosmetics benzene, glycol, esters - ANSWER synthetic lubricants are derived from 3 chemical groups benzene - ANSWER the simplest aromatic hydrocarbon, C6H6 glycol - ANSWER related alcohol containing two hydroxyl groups hydroxyl - ANSWER the chemical group or ion OH that consists of one atom of hydrogen and one of oxygen and is neutral or positively charged esters - ANSWER considered as having been made from an organic acid and an alcohol have wax because it will be deposited on the system components. Must not react chemically with refrigerant, metals, air, or motor insulation - ANSWER lubricants must not Mineral oil - ANSWER MO stands for Alkyl Benzene - ANSWER AB stands for