Topics: All categories in the pool
1: The critical temperature of a refrigerant gas occurs when
- any decrease in pressure will cause condensation
- any increase in pressure will not liquefy the gas
- the gas returns to a liquid
- the gas is no longer saturated
2: The pressure relief device of a positive displacement compressor shall discharge in the ______________or in accordance with 9.7.8
- the vapor side of the system
- high side of the system
- the liquid side of the system
- low side of the system
3: When this is installed on the high side of a system, it must be capable of reading 1.2 times the design pressure (ASHRAE 15 9.11.3)
- Pressure gauge
- Temperature gauge
- Sight glass gauge
- All of the above
4: The first step in mechanical refrigeration is
- condensation
- compression
- evaporation
- expansion
5: A professional or office building would be considered what type of occupancy?
- mercantile
- commercial
- public assembly
- business
6: 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
7: By using nitrogen within a pipe during brazing operation,
- Exterior scale formation is minimized
- The explosion hazard is confined
- Discoloration is prevented
- Copper oxide formation is prevented
8: Pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 50
- 22
- 33
- 18
9: Atmospheric pressure is equal to
- 29.92" Hg
- 14.7 psia
- 14.7 psig
- both a & b
10: What section governs pressure vessels?
- Section ASHREA 34
- Section 1 ASHREA 15 ASME fired
- Section 8 ASHREA 15 ASME unfired
- OSHA
11: What would be the classification for Stop & Shop grocery store?
- Large mercantile
- Place of assembly
- Industrial
- Instituional
12: If a purge unit fails on a low pressure chiller, what are the symptoms?
- increased capacity
- high head pressure
- low suction pressure
- low pressure chillers do not have purge units
13: Relief valves are rated in
- pounds of air per hour
- pounds of air per minute
- gallons of water per minute
- gallons of water per hour
14: A multi-evaporator refrigeration system uses what type of valve to maintain evaporating temperatures?
- Solenoid valve
- EEV
- EPR valve
- CPR valve
15: What is used to check very low air pressures in air conditioning duct?
- Anemomter
- Barometer
- Vacuum gauge
- Manometer
16: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?
- 80 ohms
- 27 ohms
- 104 ohms
- 71 ohms
17: What must be done to all doors and access points in duct work going through a mechanical room?
- Must be hindged
- Must be screwed shut
- Must be sealed and gasketed
- All of the above
18: What is the boiling point of refrigerant governed by?
- P&T relationship
- Condenser sub-cooling
- Compressor RPM's
- Evaporator temperature
19: 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
20: What is considered a cooling agent?
- any liquid used for the transmission of heat when condensation occur
- any liquid used for the transmission of heat without condensation
- any liquid used for the transmission of heat when vaporization occurs
- any liquid used for the transmission of heat without vaporization
21: Before determining if a machinery room equipment is excluded from following Ashrae 15, you must determine how many pounds of refrigerant per _____ cubic feet?
- 100,000
- 10,000
- 100
- 1,000
22: In an A/C unit, dirty filters will cause
- low oil pressure
- high discharge pressure
- high suction pressur
- low suction pressure
23: What type of relief valve is used on low pressure centrifugal compressor systems?
- Spring-loaded relief valve
- Rupture disc
- Purge relief
- None of the above
24: A water regulating valve opens when
- the head pressure rises
- the compressor is on
- when the power is on there is an overcharge of refrigerant
- when the power is on
25: When is the space above a drop ceiling calculated as space for refrigerant limit quantities?
- When there are sprinklers above
- When its white
- When there is a space 6' or more above it
- When it's used as part of a supply or return air system