Topics: All categories in the pool
1: What is a high-side float?
- Located in the liquid line entering the evaporator, so when the refrigerant level is higher in the liquid line than the evaporator, the float rises to allow more refrigerant flow into the evaporator
- Located in the liquid line entering the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the high side of the chiller
- Located in the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the low side of the chiller
- An electronic-type metering device that contains a float assembly within the device which can accurately meter refrigerant into the evaporator as the load varies
2: What type refrigerant is NOT ozone depleting?
- Halon
- HCFC
- CFC
- HFC
3: On a centrifugal compressor, stationary diffuser vanes are needed to
- convert velocity energy to pressure
- prevent high pressure on the packing
- stop gas flow
- increase the clearance space
4: What do you need to do when you install a new system?
- Have it inspected
- Add refrigerant
- Insulate the suction line before you take a superheat reading
- Document the superheat and subcooling reading
5: A secondary coolant is defined as
- a low temperature refrigerant used for cascading systems
- a combination of interconnected parts from a closed circuit in where fluid is circulated for the purpose of cooling for a refrigeration system.
- any refrigerant direcly in contact with the cooling space for process cooling
- any liquid used for the transmission of heat without a change of state in A/C refrigeration systems having flash point above 150F
6: What would be the classification of a prison?
- Institutional
- Place of assembly
- Industrial
- Large mercantile
7: A single pole-double throw switch used how many wires excluding the ground wire?
- two
- five
- four
- three
8: 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
9: Name a reason that does not cause reduced condenser air quantity
- Dirty fan blades
- Prevailing winds
- High ambient temperature
- Dirty Coil
10: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
- 80%
- 75%
- 99%
- 90%
11: In a system designed for sub-zero ambient temperatures, what must be added?
- Booster compressor
- Infrared dye for leak identification
- Low-ambient kit
- Nitrogen
12: The amount of heat required to raise the temperature of 1 lb of water 1F is?
- The rate of conduction
- 1 Therm
- 1 Kelvin
- 1 BTU
13: It is permissible to use a single-pole switch on a 2 HP motor running at 240 volts as long as the switch is rated for at least 2x FLA.
- True
- False
14: What kind of system uses two different refrigerants in separate systems dependent on each other?
- Cascade
- Low pressure
- R-414B
- Simple
15: What type of copper is not permitted on refrigeration systems?
- Type M
- Type L
- Type N
- Type K
16: What is specific heat?
- measured heat
- heat required to raise the temperature of 1lb of a substance 1 degree
- the specific heat required to change the state of one cubic foot of air to steam
- none of the above
17: A relief valve shall be located at least ___ above grade.
- 36'
- 25'
- 15'
- 10'
18: Field Inspections of refrigeration and A/C systems in Massachusetts shall be made by
- District Engineering Inspectors
- Commissioned Inspectors
- Master licensed Technician
- both a or b
19: What are the three components of a transformer?
- Primary core, secondary coil, and high and low voltage connectors.
- Primary coil, secondary coil, and copper contacts
- Primary coil, secondary coil, and core
- Contacts, secondary coil, and core
20: Which refrigerant is lighter than air?
- R-11
- R-123
- R-717
- R-134a
21: A mixed occupancy occurs when two or more occupancies are located with the same building
- true
- false
22: How far from the window does a relief valve need to be according to ASHRAE-15?
- There is no minimum for relief valve and windows.
- At least 40'
- At least 20'
- At least 30'
23: 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
24: Halo-carbon refrigerants cannot be used with what material?
- Aluminum
- Stainless Steel
- Magnesium alloy
- Copper
25: An example of direct system is
- rooftop unit
- chiller
- absorber
- none of the above