Topics: All categories in the pool
1: Mercury was used in thermometers primarily because it
- vaporizes at very high temperatures
- never freezes
- was inexpensive
- expands uniformly
2: On a TXV, the purpose of an external equalizer is to?
- compensate for a pressure drop across the evaporator coil
- allow a greater adjustment spam
- Increase the pressure on the top of the power head diaphragm
- balance the evaporator load
3: High side floats are used on centrifugal chiller systems are are considered critically charged systems.
- are obsolete.
- False
- depends on the type of refrigerant being used
- True
4: Pipe identification labels are required when the system contains more than
- 120 lbs
- 65 lbs
- 110 lbs
- 55 lbs
5: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
- 330 lbs
- 55 lbs
- 660 lbs
- 500 lbs
6: The External equalizer of a TXV compensates for
- pressure drop across the condenser coil
- pressure drop across the evaporator coil
- pressure within the evaporator
- pressure within the system
7: What is the voltage of each leg to ground of a three-phase motor with a 460v supply voltage?
- 240v
- 120v
- 277v
- 208v
8: Horizontal piping should be run level.
- No, unless the supervisor on the job says so.
- False
- Yes, if the condenser is located above the evaporator
- True
9: Which of the following controllers would you expect to be most sensitive to temperature changes?
- low voltage t-stat
- aquastat
- immersion controller
- line voltage t-stat
10: Two systems using separate refrigerants that are superimposed upon one another is called
- indirect
- cascade
- single stage
- booster
11: The main purpose of the accumulator is to
- provide space for vapor to accumulate
- provide space for the accumulation of oil and containminants
- prevent liquid slugs at the compressor
- store liquid refrigerant
12: Where a refrigeration or air conditioning system is installed,
- The company who installed the system must notify the fire department in the jurisdiction where installed
- A field inspection shall be made before it is put into service
- it shall not be operated below prescribed pressuers
- the form or certificate shall be authorized by the Department of Public Safety
13: R-12 is
- dichlorodifluoromethane
- dichlorofluoromethane
- dichloromethane
- trichlorofluoromethane
14: What refrigerant doesn't have to be classified?
- R-422A
- R-718
- R-717
- R-134A
15: The best way to detect ammonia in brine is
- carbonation of soda
- CO2 gas
- potassium of line
- nessler regaent
16: A mercury bulb controller is not recommended for
- use where vibration is severe
- line or low voltage use
- low voltage use
- line voltage use
17: A mixed occupancy occurs when two or more occupancies are located with the same building
- true
- false
18: Booster compressors, pump refrigerant into the
- low side of the primary compressor
- heat & plate heat exchanges
- receiver
- high side of the secondary compressor
19: Low temperature systems should have what?
- High pour point
- Low pour point
- High viscosity
- None of the above
20: R-410A can segregate in the system or chemically change its composition due to a leak.
- True
- False
21: If two 500 ohm resistors are connected in series, the resistance will be
- 1000 ohms
- 20 ohms
- 200 ohms
- 500 ohms
22: What's the purpose of a megohmmeter?
- To measure low to very low resistance values
- To alternate the current in a DC circuit in order to calculate the total impedance of a circuit
- To measure very high resistances
- None of the above
23: When should a relief valve start to function?
- 10 psi before it's set pressure
- Before the purge station discharges
- Two times it's working pressure
- At it's set pressure
24: Joints in piping for refrigeration containing parts must withstand temperatures of ___?
- 700F
- 1000F
- 600F
- 800F
25: How far from the ground does a relief valve need to be?
- At least 25' above grade
- Not more than 3' above grade
- At least 15' above grade
- At least 20' above grade