Topics: All categories in the pool
1: What happens to copper joints when overheated?
- nothing
- joint becomes oxidized and ditorted
- copper becomes harder
- none of the above
2: A high side float is a
- metering device used on critically charged systems that controls the level of the liquid refrigerant in the high pressure side of the system.
- float type valve that controls the amount of refrigerant stored in the receiver
- float type switch that stops the compressor when the pressure on the high side becomes too high
- float type valve that controls the crankcase oil level
3: What is Trichlorotrifluoromethane?
- R-11
- R-13
- R-12
- R-113
4: The main purpose of a refrigerant detector in a machinery room is to
- inform there is a refrigerant leak int he system
- detect toxins in the air caused by a refrigerant leak
- to set off an alarm when there is refrigerant present inside the room
- all of the above
5: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
- high pressure
- critical pressure
- low pressure
- design pressure
6: Who approves containers for refrigerants?
- D.O.E
- D.O.T
- D.O.D
- E.P.A
7: How many BTU's is produced by one watt of energy
- 1
- 3.00
- 2.57
- 3.41
8: A R-22 system running with a condensing temperature of 110F and a 40F evaporator temperature will read pressures of ____ on the high side and ____ on the low side.
- 226 psig, 68 psig
- 257 psig, 77 psig
- 350 psig, 120 psig
- 455 psig, 185 psig
9: What pipe can not be used for refrigeration?
- M
- N
- K
- L
10: R-22 is considered a(n)
- CFC
- HFC
- HCFC
- HCFCH
11: A low oil switch is typically
- automatic reset
- manual reset
- time-delay auto reset
- non used on semi-hermetic compressors over 10 ton capacity
12: When energized, a normally open relay will be
- noisy
- depends on the type and class of the relay
- open
- closed
13: What type of fuses must be used on a HVAC system?
- TR Type, Duel Element, Time Delay
- Fast blow
- 10% lower than RLA
- none of the above
14: A motor starter is a device that includes an overload and a _______?
- contactor
- 2-pole contacts
- duel-coil
- all of the above
15: Evaporators located ____inches of a heating coil shall be equipped whit a pressure relief device.
- 15
- 24
- 18
- 10
16: A self contained system
- is a unit system Group I refrigerants only
- is a unit system Group II refrigerants only
- is a complete factory made and tested system
- is any system or part of a system used to increase evaporation by expansion or vaporization
17: Stop valves shall not be permitted between the system and the
- relief valve
- bleed valve
- condenser
- service valve
18: Refrigeration devices shall be equipped with a ____ to protect against unexpected pressure due to a malfunction or fire?
- Relief valve
- T&P device
- Temperature limiter device
- Circuit Breaker
19: On a ammonia compressor, the pressure of a forced fed oil pump is changed by varying the
- opening at the pump inlet
- cooling temperature set-point
- opening at the pump outlet
- adjustment of the spring tension of the TXV
20: On cooling towers, what causes the condenser water to drop
- ambient temperatures
- sensible heat
- tower fans
- evaporation of the water droplets
21: On a pumpdown system, the liquid-line solenoid is controlled by the
- thermostat
- low-ambient controller
- defrost timer
- low pressure switch
22: Low pressure chiller systems use what type of compressor?
- Reciprocating
- Screw
- Scroll
- Centrifugal
23: A mercury bulb controller is not recommended for
- line or low voltage use
- line voltage use
- use where vibration is severe
- low voltage use
24: What is the typical air conditioning operating pressures for 410A?
- 60 psi suction, 210 psi discharge
- 25 psi suction, 125 psi discharge
- 105 psi suction, 350 psi discharge
- None of the above
25: What is not a requirement of a class T machine room?
- tight fitting doors
- automatic ventilation
- fire hose connection to the building fire protection system
- self-closing doors