Topics: All categories in the pool
1: A direct system
- is one which encloses a separate body of evaporative refrigerant
- is a self-contained complete factory made and tested system
- is where the refrigerant comes in contact with the space refrigerated
- is on where brine is cooled & circulated to the space refrigerated
2: A 120 volt motor rated at 1,800 watts. You find the motor is drawings 25 amps. The motor is
- drawing RLA and is running as it should
- drawing LRA and is seized and should be replaced.
- running hot
- none of the above
3: If the suction pressure is low and the evaporator temperature high, the cause will be a?
- too small evaporator
- starved evaporator
- compressor suction valve stuck open
- overcharged
4: The gauge thickness required on a CO2 tank construction is
- 1/8"
- 5/16"
- 1/16"
- 3/32"
5: Systems containing more than 110 pounds must have stop valves located at the
- compressor suction inlet
- compressor discharge outlet
- receiver inlet and outlet
- All of the above
6: What should never be used in pressure testing refrigeration systems?
- Oxygen
- Compressed air
- Nitrogen
- Both a and b
7: What kind of material can't be used on the outlet of a relief valve?
- Copper
- Stainless Steel
- PVC
- Aluminum
8: Heat transferred by conduction from one body to another is done
- via liquids
- via radiation
- via solids
- via heat rays
9: Pressure relief valves shall be marked with the data from
- Section IV Division of the ASME Boiler & Pressure Code
- Section VIII Division of the ASME Boiler & Pressure Code
- Section XIII Division of the ASME Boiler & Pressure Code
- Section I Division VIII of ASME Boiler & Pressure Code
10: No open flames are allowed in the machinery room unless?
- Never can be allowed
- Only when combustion air is provided from outside of the machinery room
- Approved by the authorized person
- Approved by the installing contractor
11: A machine room with a refrigerant system using ammonia shall
- be provided with a continuously operated ventilation system
- be considered a non-hazardous location in accordance with National Electrical code
- have no flame producing apparatus permanently installed and operated
- All of the above
12: What measures gas pressure?
- Hygrometer
- Manometer
- Barometer
- Hydrometer
13: All machine rooms must be outfitted with a detector that _______?
- activates an audible alarm
- activates a visual alarm
- starts the ventilation system
- All of the above
14: On a single phase motor, when does the start winding cut out?
- 50% of its RLA speed
- 75% of its RLA speed
- 100% of its RLA speed
- 25% of its RLA speed
15: 14.7 psia is equivalent to
- atmospheric pressure at seal level
- 29.92" Hg
- 0 psig
- All of the above.
16: Laten heat is associated with a change in state of a refrigerant but not temperature
- True
- False
17: The two float-type metering devices are the
- high-side float and the low-side float
- liquid float and the low-side float
- liquid float and the vapor float
- vapor float and the low-side float.
18: Low ambient controls are used when
- on air conditioning systems only
- when systems run all year round
- economizers are used
- always
19: In a horizontal shell & tube condenser, the ammonia is liquefied by
- passing thru the tubes from top to bottom
- removing the latent heat of fusion
- removing the latent heat of vaporization
- water sprayed over condenser
20: A line voltage thermostat controls a 1,200 watt strip header at 120 volts. What must be minimum ampere rated of the stat be?
- 15 amps
- 20 amps
- 10 amps
- 5 amps
21: Pressure vessels of 10 cubic feet or more gross volume shall use
- at least one rupture member
- a dual pressure-relief valve if charging into the atmosphere
- at least three means of discharge and/or rupture discs
- both a and b are correct
22: What is used to check very low air pressures in air conditioning duct?
- Barometer
- Vacuum gauge
- Manometer
- Anemomter
23: The ASHRAE Standard 34 requires what type of alarm for equipment rooms using HCFC-123?
- A group sensing
- phosgene gas sening
- refrigerant sensing
- CO Sensing
24: Where a refrigeration or air conditioning system is installed,
- the form or certificate shall be authorized by the Department of Public Safety
- A field inspection shall be made before it is put into service
- it shall not be operated below prescribed pressuers
- The company who installed the system must notify the fire department in the jurisdiction where installed
25: R-718 is rated unlimited for refrigeration quantity contained in a system. Why?
- R-718 is not rated unlimited because it's a dangerous refrigerant
- Because it's a non-flammable refrigerant
- Because it's water
- Because it's cheap