Topics: All categories in the pool
1: How does a centrifugal compressor create the pressure differential needed to move refrigerant through the system?
- Fan-like action
- Rotating vanes
- Nesting scrolls
- Suction and discharge valves
2: With a 5/8" X 5/8" x 3/4" tee, what size is the center connection?
- 5/8"
- 3/8"
- 1/2"
- 3/4"
3: Refrigerants shall be classified by
- toxicity and flammability
- color codes
- maximum permissible quantities of each group
- requirements for commercial, industrial, and residential occupancies
4: When using nitrogen for brazing, the pressure should be:
- 50-100 psig
- Very low
- 125 psig
- Slightly below atmospheric
5: What is an example of institutional occupancy?
- Football stadium
- Shopping mall
- Dorms
- Hospital
6: Capacity control on an absorption system is typically accomplished by varying the
- pressure setting on the system's rupture disc
- rate at which heat is supplied to the concentrator
- speed of the condenser water circulator pump
- speed of the chilled water circulatory pump
7: Which refrigerant class listed below is the most flammable?
- B-2
- A-1
- A-3
- C-3
8: What must be done to refrigerant pipes before being buried?
- Certified
- Leaked checked
- Encased
- Coated
9: Which is considered the more efficient condenser?
- air cooled
- fan cooled
- spray cooled
- water cooled
10: A positive displacement compressor is
- is a reciprocating type compressor with 2 or more pistons
- a compressor in which the increase in pressure is attained by changing the internal pressure of the compression chamber
- a compressor in which the increase in pressure is attained by changing the internal volume of the compression chamber
- where the compressor's suction pressure and the compressor;s discharge pressure is more than 50 PSI
11: A 24 volt transformer with a 240 volt primary can handle how many amps?
- 20 amps
- There isn't enough information to answer.
- 24 amps
- 10 amps
12: "R" represents ___ in the Ohm's law formula
- amperage
- capacitance
- resistance
- voltage
13: Pressure vessels of 10 cubic feet or more gross volume shall use
- at least one rupture member
- a dual pressure-relief valve if charging into the atmosphere
- at least three means of discharge and/or rupture discs
- both a and b are correct
14: Liquid level gauges shall have _____________ with one exception being that of the liquid level gauge bull’s eye type.
- color-coded glass to determine type of refrigerant
- moisture indicators
- automatic closing shut-off valves
- All of the above
15: The solution that leaves the concentrator in an absorption chiller is referred to as the
- diluted solution
- strong solution
- weak solution
- absorbed solution
16: A pressure vessel having an inside diameter of 6” or less shall be sufficient to withstand ____times the pressure of the saturation temperature of the refrigerant or ____times the critical pressure of the refrigerant, whichever is less.
- 2.5, 2.5
- 6.6, 6.6
- 3.0, 3.5
- 2.5, 3.0
17: If a refrigerant leaving the condenser is 105F and the condensing temperature is 94F, the subcooling is
- 29F
- 21F
- 11F
- 9F
18: All low-pressure chillers use which type of compressor?
- Reciprocating
- Rotary
- Centrifugal
- Scroll
19: An air conditioning system rated for 36,000 BTU's is equivalent to
- two tons of cooling
- three tons of cooling
- one ton of cooling
- 12,000 tons of cooling
20: How many gallons of water per pound of ammonia do you need?
- 15
- 5
- 1
- 20
21: What should not (and can not) be located between a pressure imposing device and a pressure-limiting device?
- Muffler
- Moisture indicator
- Stop valve
- Foot valve
22: Who is permitted to access a refrigeration machine room?
- Authorized persons only
- Contractors only
- Any employee
- Anyone, it's a completely safe area
23: R-22 is classified as a ____ refrigerant on the safety matrix.
- A-2
- B-1
- B-2
- A-1
24: Ohm's Law indicates Amps X Resistance = ___________.
- Ohms
- Current
- Impedance
- Volts
25: 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