Topics: All categories in the pool
1: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is
- run voltage
- pick up voltage
- boost voltage
- lift voltage
2: Pressure vessels with an internal volume of 10 cubic feet or more
- shall use pressure relief devices or fusible plugs
- shall use rupture discs or duel pressure relief valves
- shall use fusible plugs
- shall use pressure relief devices
3: A Low-Probability System
- is a system highly likely to leak form a failed connection or component of such system
- is such that any leak will cause injury or death to anyone within a 100 square foot area
- is such that a leak of refrigerant from a failed connection will enter the occupied space
- is such that a leak of refrigerant from a failed connection can not enter the occupied space
4: If a condenser is on a roof and the temperature is 35F and dropping the capacity
- decreases
- run as designed with low ambient controls
- doesn't change
- increases
5: When the compressor is below the condensor
- traps are needed on the discharge line
- traps are not needed on this type of system
- traps are needed on the oil return line
- traps are needed on the suction line
6: Where must a refrigeration contractor's license number be displayed?
- Uniforms, checks, and invoices.
- Trucks, invoices, and advertising
- Truck, office, every job, and on all equipment
- Trucks, license plates, and uniforms
7: Most CFC's are
- toxic
- inert but toxic
- flammable
- inert
8: 746 watts is equal to
- 10 hp
- 1 hp
- Pi
- 100 hp
9: A mixed occupancy occurs when two or more occupancies are located with the same building
- true
- false
10: What is used to check very low air pressures in air conditioning duct?
- Manometer
- Anemomter
- Barometer
- Vacuum gauge
11: Which oil is hydoscopic?
- mineral
- polyolester
- animal
- SW30
12: What would be the classification of a church?
- Industrial
- Large mercantile
- Institutional
- Place of assembly
13: The principle used in continuous type absorption systems is
- Ohm's Law
- Charles's Law
- Boyle's Law
- Dalton's Law
14: What should never be used in pressure testing refrigeration systems?
- Oxygen
- Compressed air
- Nitrogen
- Both a and b
15: Liquid refrigerant R-22 enters an evaporator at 50.2 psig, 20F and leaves 37F, its pressure as it leaves will be
- 50.2 psig
- 66.1 psig
- 70.8 psig
- 43.3 psig
16: When a refrigeration or air conditioning system is installed
- the form of certificate shall be authorized by the Department of Pubic safety
- a field inspection shall be made before it is put into service
- it shall not be operated below prescribed pressures
- it shall be approved by the owner for proper operation.
17: In an electrical circuit, what is potential measured in?
- Herys
- Amps
- Ohms
- Volts
18: What is Trichlorotrifluoromethane?
- R-11
- R-12
- R-113
- R-13
19: Machinery rooms must be vented to ______?
- basement
- outdoors
- unoccupied spaces
- neutralizing tank
20: How many groups of refrigerants are there?
- 1
- 7
- 5
- 3
21: Excessive head pressure is often caused by
- insufficient refrigerant
- leaking reed valve on the discharge side
- thermostat set too high
- air cooled condenser is plugged
22: Each machinery room shall contain
- smoke and fire alarms as well as three means of egress and that egress must meet 528 CMR ventilation requirements
- a refrigerant detector located in an area where the refrigerant from a leak will concentrate
- high and low pressure controls
- a toxicity detector where the presence of ammonia or lithium bromide from a leak will concentrate
23: Low temperature systems should have what?
- High pour point
- Low pour point
- High viscosity
- None of the above
24: R-11 belongs to Group
- A-2
- B-1
- A-1
- B-3
25: What percentage of amperage difference is allowable phase to phase on a HVAC circuit phased to phase?
- 25%
- 1%
- 2%
- 4%