Topics: All categories in the pool
1: A start capacitor in series with a start winding will
- decrease the amp draw of the motor
- increase the amp draw of the motor
- increase running efficiency
- increase starting torque
2: Can a R22 line set be reused for a 410A system and if it can be reused, what must be done to it?
- Flush with R-718
- Flush with RX-11
- Flush with ammonia
- Flush with R-11
3: What is Absolute Zero?
- -640F
- -773F
- -400F
- -460F
4: The location of a thermal bulb of a TXV affects
- the amount of liquid in the condenser.
- the amount of liquid returning to the compressor
- the amount of liquid refrigerant in the evaporator
- subcooling
5: The Board of Boilers adopts by reference
- Montreal Protocol Safety Code
- the 1997 ANSI/ASHRAE Safety Code
- the MACS Pressure Vessel Code of Massachusetts
- MSCA Code
6: Megaohm meter's main function is
- to detect weak motor winding insulation of a refrigeration or air conditioning compressor by creating high DC voltages to the compressor
- to detect very high resistances to ground of refrigeration or air conditioning compressors
- to test very high value capacitors for large 3-phase refrigeration compressors and blower motors.
- Both a and b are correct
7: Which of the following is an example of an azeotropic refrigerant?
- R-404A
- R-500
- R-410A
- R-134A
8: Sublimation occurs when
- ice melts and turns to water
- liquid is formed from a gas
- gas is formed from a liquid
- gas is formed directly from a solid
9: Ammonia can come in contact with _______ ?
- Copper tubing
- Aluminum
- Copper
- Brass
10: A low oil switch is typically
- manual reset
- time-delay auto reset
- automatic reset
- non used on semi-hermetic compressors over 10 ton capacity
11: What is the maximum voltage range allowed on an electrical circuit?
- 20%
- 15%
- 10%
- 5%
12: On a 460V motor, what is he MAXIMUM voltage that can be safely applied to it?
- 506v
- 550v
- 660v
- None of the above
13: Which of the following most closely represents the concentration of Li-Br in a absorption system?
- 50% Li-Br, 50% tap water
- 60% Li-Br, 40% distilled water
- 40% Li-Br, 60% tap water
- 40% Li-Br, 60% distilled water
14: Refrigerant systems containing Group I refrigerants can be installed in or on public stairways.
- True
- False
15: The normal operating evaporator temperature of R-410A for air conditioning is typically
- 45F
- 155F
- 32F
- 158F
16: A 24 volt transformer with a 240 volt primary can handle how many amps?
- There isn't enough information to answer.
- 20 amps
- 10 amps
- 24 amps
17: Which occupancy can ammonia be used in?
- redifential
- industrial
- depends on the quantity of freon
- commercial
18: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
- 365 psig
- 327 psig
- 255 psig
- 125 psig
19: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
- nothing must be done
- place sign, check for leaks, insulate
- make sure it's compatible, notify owner, notify A.H.J
- you can't change refrigerants
20: A rule of thumb in air conditioning is ____ CFM per ton?
- 600
- 500
- 100
- 400
21: A multi-evaporator refrigeration system uses what type of valve to maintain evaporating temperatures?
- EEV
- CPR valve
- EPR valve
- Solenoid valve
22: What type of material can't be used on the outlet of a relief valve?
- PVC
- Magnesium alloy
- Stainless steel
- Copper
23: How far from the window does a relief valve need to be according to ASHRAE-15?
- At least 40'
- At least 20'
- At least 30'
- There is no minimum for relief valve and windows.
24: A High-Probability System
- is such that a leak of refrigerant from a failed connection will enter the occupied space
- is a system highly likely to leak form a failed connection or component of such system
- is such that any leak will cause injury or death to anyone within a 100 square foot area
- is such that a leak of refrigerant from a failed connection will enter an unoccupied space
25: Pressure vessels having design pressures of 15 psig or less shall have the strength to withstand at least ______times the design pressure.
- 2.5
- 3.0
- 2.0
- 5.5