Topics: All categories in the pool
1: What is used to check very low pressure?
- Manometer
- Velometer
- Hygrometer
- Hydrometer
2: The critical temperature of a refrigerant gas occurs when
- the gas returns to a liquid
- any decrease in pressure will cause condensation
- the gas is no longer saturated
- any increase in pressure will not liquefy the gas
3: R-12 is
- dichloromethane
- trichlorofluoromethane
- dichlorodifluoromethane
- dichlorofluoromethane
4: Starting relays for a single phase compressors are used to remove the starting circuit from operation when the motor reaches approximately ____ percent of its speed.
- 24
- 50
- 75
- 100
5: Crankcase heaters are energized
- to prevent compressor freeze-up
- while the compressor is running
- when the compressor is off
- to allow easy compressor start-up
6: If a liquid receiver is designed to receive the refrigerant charge during a pumpdown procedure, it shall have the capacity to
- receive the pumpdown charge
- release the charge when the pressure exceeds 310 psig or higher
- Pumpdown procedures are not allowed with systems containing liquid recievers
- hold up to 110% of the pumpdown charge
7: What refrigerant doesn't have to be classified?
- R-422A
- R-717
- R-134A
- R-718
8: Fusible plugs must have what marked on them?
- Melting temperature in F
- Melting temperature in C
- Opening pressure
- All of the above
9: Refrigerant piping crossing an open space that affords passageway in any building shall not be less than _____ feet above the floor unless piping is located against the ceiling.
- 7.25'
- 7.00'
- 8'4"
- 9.00'
10: The Department that certifies the transportation of refrigerant is the
- DOT
- EPA
- EPO
- RSES
11: What type of copper is not permitted on refrigeration systems?
- Type L
- Type N
- Type M
- Type K
12: What is a high-side float?
- 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
- 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
- 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
- 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
13: Each machinery room shall contain
- a toxicity detector where the presence of ammonia or lithium bromide from a leak will concentrate
- high and low pressure controls
- a refrigerant detector located in an area where the refrigerant from a leak will concentrate
- smoke and fire alarms as well as three means of egress and that egress must meet 528 CMR ventilation requirements
14: A hotel is considered a _______ occupancy.
- mercantile
- commercial
- residential
- institutional
15: 746 watts is equal to
- Pi
- 10 hp
- 1 hp
- 100 hp
16: How far from the window does a relief valve need to be according to ASHRAE-15?
- At least 20'
- At least 40'
- There is no minimum for relief valve and windows.
- At least 30'
17: How many BTU's is produced by one watt of energy
- 3.41
- 3.00
- 1
- 2.57
18: What is the voltage of each leg to ground of a three-phase motor with a 460v supply voltage?
- 120v
- 208v
- 240v
- 277v
19: How many groups of refrigerants are there?
- 5
- 7
- 3
- 1
20: How are safety controls wired in a circuit?
- Parallel
- Series
- Series/parallel
- Either series or parallel
21: If the power element of an expansion valve should lose its charge the valve would
- overfeed the evaporator
- go closed
- go open
- underfeed the evaporator
22: The solution that is pumped into the concentrator in an absorption chiller is referred to as the
- weak solution
- absorbed solution
- concentrated solution
- strong solution
23: If air is present in an absorption chilled water appliance, which of the following will most likely occur?
- The Li-Br solution will become more diluted
- Rust can form
- The Li-Br solution will become more concentrated
- System operating pressure will drop
24: A single pole-double throw switch uses how many wires?(excluding the ground)
- 2
- 5
- 3
- 4
25: A plug containing an alloy that will melt at a specific temperature to relief pressure is a
- rupture plug
- fusible plug
- relief plug
- fusion plug