Topics: All categories in the pool
1: A split-phase motor has a ______ winding and a ____ winding
- run, start
- duel-run, duel-start
- start, common
- run, common
2: No open flames are allowed in the machinery room unless?
- Never can be allowed
- Only when combustion air is provided from outside of the machinery room
- Approved by the installing contractor
- Approved by the authorized person
3: Name three things that must be done when changing refrigeration lubricant?
- You can't change lubricants.
- Make sure it's compatible, notify owner, notify AHJ
- Place sign, check for leaks, insulate
- Nothing must be done
4: In an A/C unit, dirty filters will cause
- high discharge pressure
- low oil pressure
- low suction pressure
- high suction pressur
5: In an air conditioning system, the unit of total heat energy content in an air/vapor mixture is
- Enthalpy
- Latent heat
- Specific heat
- Sensible heat
6: Fusible plugs shall not be used with pressure vessels of
- 3 cubic feet or more
- 15 square feet or less
- 3 cubic feet or less
- 15 cubic feet or more
7: According to the 522 CMR Board of Boilers, refrigerant detectors, alarms, and the refrigeration mechanical room ventilating systems shall be tested
- quarterly
- bi-annually
- annually
- regularly
8: Which of the following is not an air velocity meter?
- Hydrometer
- Anemometer
- Anemotherm
- Velometer
9: If air is present in an absorption chilled water appliance, which of the following will most likely occur?
- The Li-Br solution will become more concentrated
- The Li-Br solution will become more diluted
- System operating pressure will drop
- Rust can form
10: What is the voltage of each leg to ground of a three-phase motor with a 460v supply voltage?
- 240v
- 208v
- 120v
- 277v
11: What is an egress?
- An entrance or exit
- A valve put on the low side of the system to prevent frosting
- An escape route
- A code violation
12: A relief valve shall be located at least ___ above grade.
- 10'
- 25'
- 15'
- 36'
13: When a refrigeration or air conditioning system is installed
- the form of certificate shall be authorized by the Department of Pubic safety
- it shall be approved by the owner for proper operation.
- it shall not be operated below prescribed pressures
- a field inspection shall be made before it is put into service
14: Direct systems using Group II refrigerants
- shall not be used for air condition for human comfort
- shall be allowed to be used for human comfort.
- shall be installed per instruction of the AHJ
- shall be installed in Class T machinery rooms
15: If a refrigerant leaving the condenser is 94F and the condensing temperature is 105F, the subcooling is
- 29F
- 9F
- 21F
- 11F
16: What kind of material can't be used on the outlet of a relief valve?
- Copper
- Stainless Steel
- Aluminum
- PVC
17: The location of a thermal bulb of a TXV affects
- subcooling
- the amount of liquid refrigerant in the evaporator
- the amount of liquid in the condenser.
- the amount of liquid returning to the compressor
18: 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
- 10,000
- 100,000
- 1,000
19: Can ammonia be used on domestic system?
- yes
- no, unless there is proper ventilation system installed
- no
- yes, for systems under 10 tons
20: E = I X R is
- Amps Law
- Watts Law
- Impedance Law
- Ohms Law
21: What refrigerant doesn't have to be classifted?
- R-711
- R-717
- R-134a
- R-718
22: A plug containing an alloy that will melt at a specific temperature to relief pressure is a
- relief plug
- fusible plug
- fusion plug
- rupture plug
23: How do you find net oil pressure on a compressor?
- discharge pressure - suction pressure
- gross oil pressure - suction pressure
- gross oil pressure - discharge pressure
- all of the above
24: A Lithium-bromide system is an absorption system that
- uses ammonia as a refrigerant and lithium bromide as an absorbent
- uses salts as an absorbent and lithium bromide as a refrigerant
- uses water as a refrigerant and lithium bromide as an absorbent
- uses water as a absorbent and lithium bromide as a refrigerant
25: If a purge unit fails on a low pressure chiller, what are the symptoms?
- low suction pressure
- low pressure chillers do not have purge units
- high head pressure
- increased capacity