Topics: All categories in the pool
1: A micron is
- a larger unit of measurement than Hg
- one millonths of a centimeter
- one thousandths of a millimeter
- one millonths of a micrometer
2: In a refrigeration system, you open a valve from the condenser and collect some material on a clean white sheet of bond paper, which of the following would you most likely be testing for?
- checking the level of refrigerant in the system
- testing for oil in the system
- testing for moisture in the system
- none of the above
3: While the system is operating, the discharge line should be
- at the same temperature as the crankcase
- 10-15F warmer than ambient
- too hot to hold by hand
- room temperature
4: What section governs pressure vessels?
- Section 1 ASHREA 15 ASME fired
- Section 8 ASHREA 15 ASME unfired
- OSHA
- Section ASHREA 34
5: What is the state of the refrigerant leaving the evaporator?
- a high temperature superheated vapor
- a high temperature subcooled liquid
- a low temperature subcooled liquid
- low temperature superheated vapor
6: 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
7: At higher altitudes, the boiling point of refrigerant is
- lower
- equal to the coefficient of water at 32F
- higher
- the same
8: When is the space above a drop ceiling calculated as space for refrigerant limit quantities?
- When its white
- When it's used as part of a supply or return air system
- When there are sprinklers above
- When there is a space 6' or more above it
9: On a pumpdown system, the liquid-line solenoid is controlled by the
- thermostat
- low-ambient controller
- low pressure switch
- defrost timer
10: Ammonia belongs to Group
- B-1
- A-1
- B-2
- A-2
11: Large Mercantile occupancy is a premise or that portion of a premise where more than ____ persons congregate on levels above or below the street level to purchase personal merchandise.
- 350
- 250
- 400
- 100
12: How does a centrifugal compressor create the pressure differential needed to move refrigerant through the system?
- Suction and discharge valves
- Rotating vanes
- Fan-like action
- Nesting scrolls
13: What device should be used on low-temperature freezers?
- hot-gas by-pass
- oil separator
- discharge muffler
- high capacity TXV
14: One watt of electrical energy in a resistive heater will provide _____ BTU/hr
- 34.15
- 6.830
- 16.64
- 3.415
15: Adjusting the spring pressure on a TXV
- makes no difference
- changes subcooling
- changes superheat
- adjusts the bulb charge
16: A single pole-double throw switch uses how many wires?(excluding the ground)
- 5
- 3
- 2
- 4
17: The reversing valve is commonly used
- on commercial system that involve two different temperatures
- on all heat pumps
- on multiple compressor systems
- when the code requires a check valve
18: Humidity can be sensed with
- human hair
- bimetal
- pressure bellows
- thermometer
19: 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
20: According to ASHRAE Standard-15 9.8 Positive Displacement Compressor Protection, the pressure-relief device discharge into
- the low-pressure side of the system
- the high side of the system
- the liquid receiver
- both a and c are correct
21: A compressor that increases vapor pressure by changing the internal volume of the compression chamber is called?
- Positive displacement
- Pressure induced displacement.
- Non-positive displacement
- Low Pressure displacement
22: What refrigerant is an inorganic compound?
- Ammonia
- R-22
- R-410A
- R-132A
23: Trichlorofluoromethane is the name of what refrigerant?
- R-12
- R-113
- R-502
- R-11
24: What is the purpose of a surge capacitor on a contactor?
- to protect low voltage equipment
- to keep the contactor pulled in
- to balance the sine waves
- to provide smoother start/stops
25: Which of the following is a drop-in for R-22
- R-410A
- R-134A
- R407C
- None of the above