Topics: All categories in the pool
1: Halo-carbon refrigerants cannot be used with what material?
- Stainless Steel
- Magnesium alloy
- Copper
- Aluminum
2: What is a megaohm meter?
- An electric meter that measures very high resistance values by sending a high DC voltage signal into the object being tested
- Is an electric meter that measures extremely low resistance valves by sending high DC voltage signal into the object being tested.
- An electric meter that measures very high resistance values by sending a low voltage AC signal into the object being tested
- An electric meter used by electricians to test large 3-phase blower motors for the correct rotation
3: Brazed joints melt at temperatures above
- 1,000F
- 800F
- 1,200F
- 500F
4: When air is ducted through a machine room that services occupied space, What must be done?
- Welded and seamed.
- Ducted and sealed
- Insulated and cross broke
- Flanged and gasketed
5: If two 500 ohm resistors are connected in series, the resistance will be
- 200 ohms
- 1000 ohms
- 20 ohms
- 500 ohms
6: E = I X R is
- Amps Law
- Watts Law
- Impedance Law
- Ohms Law
7: A 24 volt transformer with a 240 volt primary can handle how many amps?
- There isn't enough information to answer.
- 20 amps
- 24 amps
- 10 amps
8: Refrigerant is metered into the evaporator on a large centrifugal chiller thru the
- low side of the system
- high side float assembly
- cap tube
- none of the above
9: How many refrigerant classifications are there for toxicity?
- 2
- 3
- 5
- 1
10: How much refrigerant can be stored in a mechanical room outside of the system?
- 150
- 100
- 330
- 200
11: A check valve is a device
- designed to allow the flow of refrigerant gas in both directions
- that is always spring loaded
- with a pressure drop
- found on high pressure steam systems
12: 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
13: Cooling tower lowers condenser water temp by
- condensation
- running fans at 100%
- running water thru a secondary heat exchanger
- evaporative cooling
14: A motor is rated for 120 volts and has a RLA (rated-load amps) of 5 amps. What is the wattage of the motor?
- 1000 watts
- 746 watts
- 5KW
- 600 watts
15: R-123 belongs to Group
- B-3
- B-2
- A-3
- B-1
16: Bubbles in the liquid line sight glass could be caused by
- plugged drier
- leaking discharge valves in the compressor
- overcharge of oil
- bad low pressure switch
17: Starting relays for a single phase compressors are used to remove the starting circuit from operation when the motor reaches approximately ____ percent of its speed.
- 50
- 75
- 100
- 24
18: All low-pressure chillers use which type of compressor?
- Rotary
- Centrifugal
- Scroll
- Reciprocating
19: How many closing forces operate a thermostatic expansion valve?
- 1
- 2
- 4
- 3
20: What type of material can't be used on the outlet of a relief valve?
- PVC
- Copper
- Stainless steel
- Magnesium alloy
21: Liquid level gauges shall have _____________ with one exception being that of the liquid level gauge bull’s eye type.
- color-coded glass to determine type of refrigerant
- moisture indicators
- automatic closing shut-off valves
- All of the above
22: Which of the following is an example of an azeotropic refrigerant?
- R-404A
- R-500
- R-134A
- R-410A
23: What does an anemometer measure?
- amperage
- velocity
- temperature
- voltage
24: What is absolute humidity?
- the amount of moisture in the air per one pound of 50% RH air
- the amount of moisture in the air in grains of cubic feet of volume
- the amount of moisture in the air in grains of square feet of volume
- none of the above
25: _____ alloys shall not be used in contact with an halogenated refrigerants.
- Magnesium
- Copper
- Zinc
- Nickel