Topics: All categories in the pool
1: 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
2: By using nitrogen within a pipe during brazing operation,
- Discoloration is prevented
- The explosion hazard is confined
- Copper oxide formation is prevented
- Exterior scale formation is minimized
3: Low pressure systems have what kind of compressor?
- Scroll
- Centrifugal
- Rotary
- Reciprocating
4: What is the purpose of a surge capacitor on a contactor?
- to protect low voltage equipment
- to provide smoother start/stops
- to balance the sine waves
- to keep the contactor pulled in
5: A class B1 refrigerant is considered
- non-toxic and non-flammable
- non-toxic but highly flammable
- toxic and somewhat flammable
- toxic but non-flammable
6: A “U” or “UM” marking a on a nameplate of a pressure vessels signifies compliance with Section VIII of
- the ASME Boiler and Pressure Vessel Code
- Section 11.3.1.5 ASHRAE 15 Standard
- the ANSI Standard 10.7.2
- both the ANSI Standard 10.7.2 and ASHRAE 15 Standard 11.3.1.5
7: A hissing noise at the expansion valve is a good indication that
- expansion valve is oversized
- gas is passing thru it
- nothing is passing thru
- liquid is passing thru it
8: Pressure relief devices are marked with a ____________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- UL and UM
- UV or UR
- UM or UL
- UL and UR
9: The normal operating evaporator temperature of R-410A for air conditioning is typically
- 158F
- 32F
- 155F
- 45F
10: The most common type of motor starter is
- part winding starter
- duel-winding starter
- delts-wye starter
- across the line starter
11: B3 refrigerants are considered
- non-toxic but non-flammable
- toxic but non-flammable
- non-toxic but flammable
- toxic and highly flammable
12: One ton of refrigeration is defined as ______ btu/minute.
- 60
- 12,000
- 200
- 720,000
13: A rule of thumb in air conditioning is ____ CFM per ton?
- 400
- 600
- 100
- 500
14: Each machinery room shall contain
- a refrigerant detector located in an area where the refrigerant from a leak will concentrate
- smoke and fire alarms as well as three means of egress and that egress must meet 528 CMR ventilation requirements
- high and low pressure controls
- a toxicity detector where the presence of ammonia or lithium bromide from a leak will concentrate
15: R-11 has the greatest corrosive effect on
- Bronze
- Copper
- Aluminum
- Magnesium
16: Increasing superheat will do what to your frost line?
- Nothing
- Decrease
- Increasae
- Could either increase or decrease depending on the load conditions
17: A solder joint melts at temperatures of
- 600F to 900F
- 400F to 800F
- less than 400F
- 1,200F to 1,500F
18: Defined process piping by code CMR (528)
- Any piping that conveys a solid, liquid or gas that is not part of the plumbing or fire protection system
- Any piping in an industrial space
- Any piping in an industrial or commercial space
- All of the above
19: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
- 330 lbs.
- 550 lbs
- 660 lbs
- 55 lbs
20: When systems are protected by a high pressure relief device, the compressor's pressure limiting device shall be set at or below ____ % of the operating pressure of the high side relief device.
- 80
- 90
- 100
- 110
21: A 24 volt transformer with a 240 volt primary can handle how many amps?
- 20 amps
- There isn't enough information to answer.
- 10 amps
- 24 amps
22: Low ambient controls are used when
- when systems run all year round
- always
- economizers are used
- on air conditioning systems only
23: Ammonia shall be discharged into ____________ or a tank containing one gallon of water for every pound of ammonia.
- the atmosphere
- a de-pressurized recovery tank with a silver top and yellow bottom
- a tank containing two pounds of a water/lithium bromide mix for every pound of ammonia
- All of the above
24: How are a compressor and condenser fan wired?
- parallel
- parallel-series
- series
- series-parallel
25: Cooling tower lowers condenser water temp by
- running water thru a secondary heat exchanger
- running fans at 100%
- condensation
- evaporative cooling