Topics: All categories in the pool
1: Megaohm meters can detect a ground in the
- 10,000,000 ohms or higher
- up to 1,000,000 ohms
- up to 1,000 ohms
- up to 10,000 ohms
2: Fractionation occurs when
- the pressures increase as the heat load increases
- the pressures decreases as the heat load decreases
- some of the blended refrigerant evaporates or condenses before the rest of the blend
- when a fraction of refrigerant is added as the full charge
3: In a motor, an internal overload might open if
- there's a direct short
- there was a high pressure refrigerant was used for a low pressure system.
- there's an open start winding
- there's an excess current draw through the motor
4: Dual-pressure relief devices should be installed on
- vessels of 3 cubic feet or more
- vessels of 3 cubic feet or less
- vessels of 10 cubic feet or more
- vessels of 10 cubic feet or less
5: 746 watts is equal to
- Pi
- 100 hp
- 10 hp
- 1 hp
6: Pressure vessels with an internal volume of 3 cubic feet or more
- shall use fusible plugs
- shall use pressure relief devices
- shall use pressure relief devices or fusible plugs
- do not need pressure relief protection
7: A normal operating evaporator temperature of R-22 for air conditioning is typically
- 32F
- 58F
- 45F
- 55F
8: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
- 70F
- 58F
- 77F
- 32F
9: Who is permitted to access a refrigeration machine room?
- Contractors only
- Anyone, it's a completely safe area
- Any employee
- Authorized persons only
10: copper and its alloys shall not be used in contact with _____ except as a component of bronze alloys for bearing or other non-refrigerant containing uses.
- CFC-11
- Lithium bromide
- ammonia
- HCFC-123
11: A secondary coolant is defined as
- 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
- a combination of interconnected parts from a closed circuit in where fluid is circulated for the purpose of cooling for a refrigeration system.
- a low temperature refrigerant used for cascading systems
12: Name an HCFC refrigerant(s):
- R-22
- R-123
- R-11
- both a & b
13: On a pumpdown system, the liquid-line solenoid is controlled by the
- defrost timer
- low-ambient controller
- low pressure switch
- thermostat
14: E = I X R is
- Ohms Law
- Watts Law
- Impedance Law
- Amps Law
15: Instead of using a compressor, an absorption air-conditioning chiller uses which of the following as its driving force?
- Oil
- Air
- Electricity
- Heat
16: Usually dry bulb temperature is
- higher than wet bulb temperature
- not important and shall be ignored
- lower than dry bulb temperature
- same as wet bulb temperature
17: The most common type of motor starter is
- delts-wye starter
- across the line starter
- duel-winding starter
- part winding starter
18: On a centrifugal compressor, stationary diffuser vanes are needed to
- increase the clearance space
- convert velocity energy to pressure
- stop gas flow
- prevent high pressure on the packing
19: What is the boiling point of refrigerant governed by?
- Evaporator temperature
- P&T relationship
- Condenser sub-cooling
- Compressor RPM's
20: How many gallons of water do you need per pound of ammonia?
- 1
- 100
- 50
- 10
21: A hotel is considered a _______ occupancy.
- commercial
- residential
- institutional
- mercantile
22: Before replacing a seized compressor, the _______ should be determinded.
- designed head pressure
- current draw
- type of refrigerant
- cause of seizure
23: On a ammonia compressor, the pressure of a forced fed oil pump is changed by varying the
- opening at the pump outlet
- adjustment of the spring tension of the TXV
- opening at the pump inlet
- cooling temperature set-point
24: When a pressure gauge is permanently installed on a system, it must be ___ times the design pressure of the system.
- 1.5
- 1.2
- 1
- 2.2
25: Which of the following types of oils are hygroscopic?
- polyolester (POE)
- polyalkylene glycol (PAG)
- naphthene mineral
- both a and b