Topics: All categories in the pool
1: A hissing noise at the expansion valve is a good indication that
- liquid is passing thru it
- nothing is passing thru
- expansion valve is oversized
- gas is passing thru it
2: R22 and 410A operate at the same range of condensing and evaporating temperatures
- true
- false
3: Usually dry bulb temperature is
- lower than dry bulb temperature
- same as wet bulb temperature
- higher than wet bulb temperature
- not important and shall be ignored
4: The test pressure applied to the high side of each factory-assembled refrigerating system shall be at least equal to the design pressure of
- the low side
- the aggregate of the high side and low side
- the high side
- 2.5 times the design pressure
5: Volts x amps equals
- Watts
- Inductance
- Impedance
- Ohms Law
6: If the spring is adjusted to increase the superheat, this new setting will
- allow more liquid into the evaporator
- shorten the frost line
- have no effect on the frost line
- lengthen the frost line
7: All low-pressure chillers use which type of compressor?
- Reciprocating
- Centrifugal
- Rotary
- Scroll
8: pressure relief valves must discharge to the atmosphere at a location not less than 15 feet from ground level and ____ feet from any window, ventilation opening, or exits of buildings.
- 20
- 15
- 10
- 25
9: What is absolute humidity?
- the amount of moisture in the air per one pound of 50% RH air
- the amount of moisture in the air in grains of cubic feet of volume
- the amount of moisture in the air in grains of square feet of volume
- none of the above
10: On a large centrifugal system, what meters the flow to the evaporator?
- Low side float
- High side float
- TXV
- Cap tube.
11: Evaporators within 18" of a heating coil must be equipped with a
- high limit control
- zone valve
- pressure relief device
- low limit control
12: If air is present in an absorption chilled water appliance, which of the following will most likely occur?
- Rust can form
- System operating pressure will drop
- The Li-Br solution will become more diluted
- The Li-Br solution will become more concentrated
13: The oil separator is always inserted in the system
- in the discharge line
- where it can be easily serviced
- to prevent oil logging
- in a cool spot
14: How many gallons of water do you need per pound of ammonia?
- 10
- 50
- 1
- 100
15: Refrigerants shall be classified by
- color codes
- toxicity and flammability
- requirements for commercial, industrial, and residential occupancies
- maximum permissible quantities of each group
16: Large vessels containing refrigerant ______________________ from using two or more pressure-relief devices in parallel to obtain the required capacity.
- of Group B2 refrigerant shall be prohibited
- containing R-11, R-123 & R-717 exclusively shall not be prohibited
- shall not be prohibited
- shall be prohibited
17: What must be done to refrigerant pipes before being buried?
- Leaked checked
- Encased
- Coated
- Certified
18: How many CFMs are required per square foot of commercial office occupied space
- 15 CFM
- .5 CFM
- 20 CFM
- 5 CFM
19: All electrical work done on refrigeration systems must comply with
- Department of Energy
- ASHREA-15 Section 9.2.1
- OSHA
- NEC and Massachusetts Modifications
20: one BTU equals
- 12,000 hp
- 3.41 hp
- Pi
- 31.4 hp
21: Ashrae states that the equipment on a building needs to conform to adjacent buildings classifications when within ____ feet from opening and intakes.
- 15
- 50
- 75
- 20
22: Before determining if a machinery room equipment is excluded from following Ashrae 15, you must determine how many pounds of refrigerant per _____ cubic feet?
- 100,000
- 10,000
- 100
- 1,000
23: What type of voltage cause a potential relay to open?
- 24 volt supply from the thermostat
- 120 volt line voltage
- Pick-up voltage
- none of the above
24: A single pole-double throw switch uses how many wires?(excluding the ground)
- 2
- 5
- 4
- 3
25: In an A/C unit, dirty filters will cause
- low oil pressure
- high discharge pressure
- high suction pressur
- low suction pressure