Topics: All categories in the pool
1: Ammonia can come in contact with _______ ?
- Copper tubing
- Brass
- Copper
- Aluminum
2: Capacity control on an absorption system is typically accomplished by varying the
- rate at which heat is supplied to the generator
- pressure setting on the system's rupture disc
- speed of the condenser water circulator pump
- speed of the chilled water circulatory pump
3: Group A3 refrigerants have a ______ flammability rating than Group B1 refrigerants
- there is no Group B1 refrigerants
- higher
- lower
- the same
4: What type of oil is used in R-410A systems?
- mineral oil
- polyolester (POE)
- polyalkylene glycol (PAG)
- naphthene
5: What does an anemometer measure?
- voltage
- temperature
- velocity
- amperage
6: If a low-pressure chiller has a low-side leak, which of the following will most likely result?
- High head pressure and low suction pressure
- Low head pressure and high suction pressure
- High suction pressure and high discharge pressure.
- Low suction pressure and low discharge pressure
7: Fusible plugs must have what marked on them?
- Melting temperature in F
- Melting temperature in C
- Opening pressure
- All of the above
8: 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.
- 90
- 100
- 80
- 110
9: A moisture indicator must
- change color when exposed to moisture
- be yellow
- be filled with liquid
- be sight side up
10: The 522 CMR 9.00 has adopted for reference ASHRAE ____
- 25
- 15
- 10
- III
11: Name an HCFC refrigerant(s):
- R-22
- R-123
- R-11
- both a & b
12: On a TXV, the purpose of an external equalizer is to?
- compensate for a pressure drop across the evaporator coil
- balance the evaporator load
- allow a greater adjustment spam
- Increase the pressure on the top of the power head diaphragm
13: Can a R22 line set be reused for a 410A system and if it can be reused, what must be done to it?
- Flush with RX-11
- Flush with R-718
- Flush with ammonia
- Flush with R-11
14: Which refrigerant replaced R-12?
- R-22
- R-407A
- R-410A
- R-134A
15: Where are the three places that the discharge from an ammonia relief valve be piped?
- To chemical neutralizing tank only
- Underground, into drain, into mechanical room
- Atmosphere, Tank containing water, where the AHJ indicates.
- None of the above.
16: What is the typical air conditioning operating pressures for 410A?
- 60 psi suction, 210 psi discharge
- 25 psi suction, 125 psi discharge
- 105 psi suction, 350 psi discharge
- None of the above
17: 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
18: Capacity control on a centrifugal compressor is accomplished by the
- post-rotational guide vanes
- slide vanes
- pre-rotational guide vanes
- check valves
19: When an inspection is needed, how often must it be done?
- annually
- every 18 months
- every 24 months
- every 36 months
20: Liquid line filter-driers on a 410A system must be rated for no less than
- 600 psig
- 400 psig
- 1000 psig
- 200 psig
21: Large Mercantile occupancy is a premise or that portion of a premise where more than ____ persons congregate on levels above or below the street level to purchase personal merchandise.
- 350
- 100
- 400
- 250
22: 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
23: Joints in piping for refrigeration containing parts must withstand temperatures of ___?
- 800F
- 1000F
- 600F
- 700F
24: The principle used in continuous type absorption systems is
- Ohm's Law
- Boyle's Law
- Dalton's Law
- Charles's Law
25: Machinery rooms shall be vented to _____________ and utilizing mechanical ventilation.
- the outdoors
- Machinery rooms need not be vented
- the return air ducted system
- the mechanical room housing the refrigeration system