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In a Freon refrigerating system in which all piping is made up of hard copper
fittings and streamlined "wrought"-type fittings, the joints should be
A) screwed
B) soldered or brazed
C) flanged with ground faces
D) flanged with lined rubber gaskets ---------CORRECT ANSWER-----------------B)
soldered or brazed
If any piece of equipment can be isolated as a separate unit
A) A gauge must be present
B) a safety valve must be installed
C) valves must be locked
D) the system must be able to run without it ---------CORRECT ANSWER---------------
--B) a safety valve must be installed
On a 220 volt, three phase, 4-wire electric service, any line will read
A) 220 volts
B) 440 volts
,C) 70 volts
D) 110 volts ---------CORRECT ANSWER-----------------D) 110 volts
If the specific heat of glass is .196, how many btu are needed to raise the
temperature of 10 pounds of glass from 50° F to 70°F?
A) 40.2
B) 39.2
C) 59.2
D) 36.2 ---------CORRECT ANSWER-----------------B) 39.2
A direct expansion (bare) coil evaporator is used to maintain a meat storage space
at 28 to 30° F. The last coil has no frost. It can be said that this system is
A) condition is acceptable to maintain a high plant efficiency
B) is a direct indication of air in the system
C) indicates moisture in the refrigerant
D) is a direct indication that the coil is being starved ---------CORRECT ANSWER-----
------------D) is a direct indication that the coil is being starved
Fuses and circuit breakers are safety devices for electric motors but they will not
protect motors against
A) short circuit
B) heavy overload
C) burnout
,D) overheating ---------CORRECT ANSWER-----------------D) overheating
Sodium chloride is not used when the temperature is
A) -20° F
B) 10° F
C) 5° F
D) 0° F ---------CORRECT ANSWER-----------------A) -20° F
The speed of a six-pole, 50-cycle motor is
A) 600 RPM
B) 1000 RPM
C) 1800 RPM
D) 3600 RPM ---------CORRECT ANSWER-----------------B) 1000 RPM
The rated discharge capacity of the pressure-relief device or fusible plug for a
refrigerant-containing vessel is determined by the formula C = Fd1. "C" equals
A) btu/minute
B) refrigerant pressure
C) air in pounds/minute
D) cubic feet/minute ---------CORRECT ANSWER-----------------C) air in
pounds/minute
, Rupture members, when used in parallel with a relief valve, are not to exceed
_____% above designed working pressure ---------CORRECT ANSWER-----------------
20%
Butterfly valve: where can it be used? ---------CORRECT ANSWER-----------------Can
be used on the inlet and outlet of a water pump
What electrical motor protection device automatically resets itself? ---------
CORRECT ANSWER-----------------The thermal protector
746 watts equals how many kilowatt hours? ---------CORRECT ANSWER----------------
-.746 kilowatt hours
What position is the liquid line service valve normally in? ---------CORRECT
ANSWER-----------------Back-seated
In an operating evaporator, oil stays on top of which refrigerant? ---------CORRECT
ANSWER-----------------Carbon dioxide, R-744