Answer the Correct Option for the Following Vapor Barrier Flashcards

The vapour barrier of a walk in cooler will be located: A) between the inner wall and the insulation b) between the inner and outer wall within the insulation c) between the outer wall and insulation d) a vapour barrier is not required within a cooler

What component is connected to terminals 3 & X of the electro-mechancial deforst time clock? a) defrost timer motor b) defrost termination solenoid c) defrost heater d) evaporator fan motor

What is the procedure for testing the oil failure control saftety contacts? a) remove jumper between terminails 2 & M b) install jumper arcoss pressure differential switch c) in 3 wire control install jumper between terminals 2 & M d) install jumper across terminals L & M

What is the acceptable method of presure testing a refrigeration system? a) low side components tested at high side pressure relief setting b) high side components tested at low side pressure relief setting c) system tested at high side design pressure d) system tested at components design pressure

What component is removed first when replacing a shaft seal on an inline booster? a) motor b) coupling housing c) pump housing d) impeller

What components are removed when replacing a seal on a close-coupled, end suction pump? a) motor & coupling bracket b) coupling bracket and pump volute c) pump volute and impeller d) impeller and pump assembly

Pipe supports must be located within what distance of a change of pipe direction? a) 1ft. b) 2ft. c) 3ft. d) 4ft.

When sizing an exhaust fan for a building, what should be considered? a) makeup air unit b) building space pressurization c) gas fired appliances d) all of the above

Which of the following is an azeotrope refrigerant? a) ternary blend having similiar pressure temperature characteristics b) binary blend having similiar pressure temperature characteristics c) a single components refrigerant d) ammonia

Which type of refrigerant will have a tendency of fractionate when vapour charging? a) a single component refrigerant b) a binary blend refrigerant c) a ternary blend refrigerant d) a natural refrigerant

A technician changes the valve plate on a compressor because the system will not pull down to temperature. Upon completion of the repair and charging of the system, the system operation still does not pull down to temperature. what is the problem? a) system is vapour charged with a single component refrigerant b) system is liquid charged with an azeotrope refrigerant c) system is vapour charged with a natural refrigerant d) system is vapour charged with a Zeotrope refrigerant

The procedure for storing recovery cylinders is: a) secured, horizontal, caps in place and below 125F b) secured, caps in place, vertical and below 125F c) secured, caps in place, vertical and above 125F d) below 125F, caps in place and in a vertical position

A di-electric union is used when connecting: a) brass to black iron b) brass to copper c) brass to plastic d) copper to plastic

What is the refrigerant mass flow rate in LB/min, of a 15 ton system, having an NRE of 56 BTU/LB? a) 50.5 b) 51.6 c) 52.6 d) 53.6

Chilled water coils have the following configuration: a) cool entering top, warm leaving top b) cool entering bottom, warm leaving top c) cool entering top, warm leaving bottow d) cool entering bottom, cool leaving top