Topics: All categories in the pool
1: What happens to copper joints when overheated?
- nothing
- joint becomes oxidized and ditorted
- copper becomes harder
- none of the above
2: What is the temperature that a liquid and a vapor can exist in equilibrium called?
- Dry bulb temperature
- Saturated temperature
- Wet bulb temperature
- Critical temperature
3: An example of an "Expendable Refrigerant" is
- liquid oxygen
- ammonia
- lithium bromide
- liquid nitrogen
4: Clearance volume
- is the same on all compressors
- varies depending on compressor speed
- affects compressor capacity
- has no effect on compressor capacity
5: What was the main reason for enacting the no venting rule of July 1, 1992?
- Ozone depletion
- Green house effect
- Global warming potential
- All of the above
6: Walls and doors of a machinery room shall be at least _____ hour(s) fire rated.
- 1
- 2
- 5
- 3
7: A halide torch is most useful with a freon compression system
- to release a sticking valve
- to detect refrigeration leaks in piping joints
- to remove from from TXV's and evaporator coils
- to sweat flanges on the refrigeration piping
8: Class 3 refrigerants are
- non-toxic
- toxic
- highly flammable
- non-flammable
9: What is the purpose of suction/discharge traps?
- to ensure proper oil return to the compressor
- to keep oil inside the evaporator for proper oil return to the compressor
- to keep oil inside of the accumulator for proper return to the compressor
- all of the above
10: Which winding have the most turns?
- depends on the motor phase
- Start
- they have equal amount of turns
- run
11: Trichlorofluoromethane is the name of what refrigerant?
- R-11
- R-113
- R-502
- R-12
12: Pressure limiting devices are not required for systems containing less then ________ refrigerants.
- 6.6 lbs
- 22 lbs
- 44 lbs
- 13.9 lbs
13: Excessive head pressure is often caused by
- thermostat set too high
- leaking reed valve on the discharge side
- insufficient refrigerant
- air cooled condenser is plugged
14: What is the voltage of each leg to ground of a three-phase motor with a 460v supply voltage?
- 240v
- 277v
- 208v
- 120v
15: On a TXV, the purpose of an external equalizer is to?
- compensate for a pressure drop across the evaporator coil
- balance the evaporator load
- Increase the pressure on the top of the power head diaphragm
- allow a greater adjustment spam
16: A motor starter is a device that includes an overload and a _______?
- contactor
- 2-pole contacts
- duel-coil
- all of the above
17: _____ and its alloys are suitable for use with ammonia systems.
- Copper
- Zinc
- Magnesium
- Aluminum
18: A motor starter contains a thermal overload and a
- transformer
- contactor
- solenoid
- 3-way relay
19: A start capacitor is wired in _____ with the start windings.
- series-parallel
- series
- junction
- parallel
20: 746 watts is equal to
- 1 hp
- 10 hp
- Pi
- 100 hp
21: The principle used in continuous type absorption systems is
- Charles's Law
- Boyle's Law
- Ohm's Law
- Dalton's Law
22: A 3-cubic foot receiver must have what type of relief valve?
- fusible plug
- relief valve
- rupture device
- none of the above
23: Name a CFC refrigerant(s):
- R-11
- R-12
- R-123
- both a & b
24: Where are the three places that the discharge from an ammonia relief valve be piped?
- atmosphere, tank containing water, where the A.H.J. indicates
- underground, into drain, into mechanical room
- to chemical neutralizing tank only
- none of the above
25: What is specific heat?
- measured heat
- heat required to raise the temperature of 1lb of a substance 1 degree
- the specific heat required to change the state of one cubic foot of air to steam
- none of the above