Topics: All categories in the pool
1: What is a high-side float?
- Located in the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the low side of the chiller
- Located in the liquid line entering the evaporator, so when the refrigerant level is higher in the liquid line than the evaporator, the float rises to allow more refrigerant flow into the evaporator
- An electronic-type metering device that contains a float assembly within the device which can accurately meter refrigerant into the evaporator as the load varies
- Located in the liquid line entering the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the high side of the chiller
2: While the system is operating, the discharge line should be
- room temperature
- too hot to hold by hand
- 10-15F warmer than ambient
- at the same temperature as the crankcase
3: Name a CFC refrigerant(s):
- R-11
- R-12
- R-123
- both a & b
4: copper and its alloys shall not be used in contact with _____ except as a component of bronze alloys for bearing or other non-refrigerant containing uses.
- HCFC-123
- Lithium bromide
- CFC-11
- ammonia
5: Transformers are rated in
- volt-amps
- amps
- volts-ohms
- volts
6: Booster compressors connect to the ____ side of the compressor
- oil side
- liquid
- vapor
- low side
7: Halogenated refrigerants cannot be used with what material?
- Magnesium alloy
- Stainless steel
- Copper
- Aluminum
8: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
- 70F
- 58F
- 32F
- 77F
9: The purpose of a receiver is
- a vessel to store refrigerant outside the system
- to increase the capacity that the system can hold
- to use a a later date
- all of the above
10: A high side float is a
- 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
- float type valve that controls the amount of refrigerant stored in the receiver
- metering device used on critically charged systems that controls the level of the liquid refrigerant in the high pressure side of the system.
11: 746 watts is equal to
- Pi
- 100 hp
- 10 hp
- 1 hp
12: What should not (and can not) be located between a pressure imposing device and a pressure-limiting device?
- Foot valve
- Moisture indicator
- Stop valve
- Muffler
13: How do you find net oil pressure on a compressor?
- discharge pressure - suction pressure
- gross oil pressure - suction pressure
- gross oil pressure - discharge pressure
- all of the above
14: A halide torch is most useful with a freon compression system
- to remove from from TXV's and evaporator coils
- to sweat flanges on the refrigeration piping
- to release a sticking valve
- to detect refrigeration leaks in piping joints
15: A professional or office building would be considered what type of occupancy?
- commercial
- mercantile
- business
- public assembly
16: At higher altitudes, boiling temperatures
- are unaffected
- depends on the refrigerant
- decrease
- increase
17: What type of voltage cause a potential relay to open?
- 24 volt supply from the thermostat
- 120 volt line voltage
- Pick-up voltage
- none of the above
18: Class T machine room
- shall include closets used for setting equipment
- shall have refrigerant leak detecting systems installed inside and outside the room
- has no flame producing apparatus permanently installed
- shall have remote controls to stop the action of the refrigerant compressor
19: High pressure controls should be set no higher than
- 80% of set point
- 10% of set point
- 90% of set point
- 25% of set point
20: Which creates more of a heat load?
- 70% RH
- 30% RH
- 90% RH
- 50% RH
21: If your suction line is warmer than the room temperature, this may indicate
- an over charge
- a low charge
- plugged air filter
- below normal superheat
22: Whoever owns/uses a refrigeration or air conditioning system covered by this code
- must notify the Department of Public Safety prior to starting the system
- shall be licensed by the Commonwealth of Massachusetts according to CMR 522
- shall make application for inspections to the Chief of Inspectors
- None of the above
23: What type of material can't be used on the outlet of a relief valve?
- Stainless steel
- Magnesium alloy
- PVC
- Copper
24: A chilled water pump suction gauge reads 10 psig. Discharge gauge reads 48 psig. The head in feet of the pump is working against
- 38
- 116
- 108
- 88
25: Low temperature systems should have what?
- High pour point
- Low pour point
- High viscosity
- None of the above