Topics: All categories in the pool
1: Each machinery room shall contain
- high and low pressure controls
- smoke and fire alarms as well as three means of egress and that egress must meet 528 CMR ventilation requirements
- a refrigerant detector located in an area where the refrigerant from a leak will concentrate
- a toxicity detector where the presence of ammonia or lithium bromide from a leak will concentrate
2: 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
3: Group A1 refrigerants over ____ pounds in a system must discharge to the atmosphere
- 6.6
- 1,000
- 330
- 110
4: What device should be used on low-temperature freezers?
- oil separator
- hot-gas by-pass
- discharge muffler
- high capacity TXV
5: Relief valves are rated in
- gallons of water per minute
- pounds of air per hour
- pounds of air per minute
- gallons of water per hour
6: What happens to copper joints when overheated?
- nothing
- joint becomes oxidized and ditorted
- copper becomes harder
- none of the above
7: If the suction pressure is low and the evaporator temperature high, the cause will be a?
- overcharged
- starved evaporator
- compressor suction valve stuck open
- too small evaporator
8: A EPR valve is installed on what type of evaporators?
- shell and tube evaporators
- plate evaporators
- low-temperature evaporators
- high-temperature evaporators
9: 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
10: Pairs of mating stop valves that allow sections of a system to be joined before opening these valves or separated after closing them are
- companion or block valves
- king valves
- ball valves
- gate or globe valves
11: 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
12: E = I X R is
- Amps Law
- Ohms Law
- Impedance Law
- Watts Law
13: Capacity control on a centrifugal compressor is accomplished by the
- slide vanes
- post-rotational guide vanes
- check valves
- pre-rotational guide vanes
14: "R" represents ___ in the Ohm's law formula
- resistance
- amperage
- voltage
- capacitance
15: All serviceable components of a refrigeration system shall be provided with
- service manuals
- name plates with markings referring to pressure and temperature in accordance with ASME Boiler and Pressure Vessel Code
- manufactures instructions on start-up procedures
- safe access
16: The location of a thermal bulb of a TXV affects
- the amount of liquid in the condenser.
- the amount of liquid refrigerant in the evaporator
- subcooling
- the amount of liquid returning to the compressor
17: 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
18: A single pole-double throw switch uses how many wires?(excluding the ground)
- 3
- 2
- 4
- 5
19: When an A/C system is excessively low on refrigerant
- it can become contaminated with water
- there can be nuisance trip outs
- the suction line may be too hot to touch
- All of the above
20: Emergency shutdown procedures, including precautions to be observed in case of a breakdown or leak over 55 lbs of refrigerant charge, shall be displayed on a conspicuous card located as near as possible to the
- outside the machinery room
- compressor
- boiler
- evaporator
21: What is Trichlorotrifluoromethane?
- R-12
- R-13
- R-113
- R-11
22: The freezing point of water at sea level is?
- 0F
- 32F
- -10C
- 32C
23: Pressure relief devices are marked with a ____________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- UM or UL
- UL and UM
- UV or UR
- UL and UR
24: Cooling tower lowers condenser water temp by
- evaporative cooling
- running water thru a secondary heat exchanger
- running fans at 100%
- condensation
25: Color is important in oil because
- can tell us something about the refining of oil
- it indicates the viscoisty.
- it makes sight glasses easy to read
- allows you to see into crankcase