Topics: All categories in the pool
1: What is potential measured in?
- Ohms
- Henrys
- Volts
- Amps
2: No open flames are allowed in the machinery room unless?
- Approved by the installing contractor
- Approved by the authorized person
- Only when combustion air is provided from outside of the machinery room
- Never can be allowed
3: How many closing forces operate a thermostatic expansion valve?
- 3
- 2
- 1
- 4
4: A moisture indicator must
- be filled with liquid
- be yellow
- change color when exposed to moisture
- be sight side up
5: How are refrigerant blends classified?
- Blends don't have to be classified
- Based on best case Fractionation
- Based on worst case fractionation
- Based on the oil used
6: Where can 50/50 solder be used on?
- suction line
- liquid line
- discharge line
- none of the above
7: If the spring is adjusted to increase the superheat, this new setting will
- allow more liquid into the evaporator
- shorten the frost line
- have no effect on the frost line
- lengthen the frost line
8: Fusible plugs shall not be used with pressure vessels of
- 3 cubic feet or more
- 15 cubic feet or more
- 15 square feet or less
- 3 cubic feet or less
9: A Lithium-bromide system is an absorption system that
- uses salts as an absorbent and lithium bromide as a refrigerant
- uses ammonia as a refrigerant and lithium bromide as an absorbent
- uses water as a refrigerant and lithium bromide as an absorbent
- uses water as a absorbent and lithium bromide as a refrigerant
10: How many volts would you read on a 480V system phase to phase?
- 480
- 277
- 1/3 the voltage
11: How are safety controls wired in a circuit?
- Parallel
- Series
- Either series or parallel
- Series/parallel
12: What happens to copper joints when overheated?
- nothing
- joint becomes oxidized and ditorted
- copper becomes harder
- none of the above
13: "R" represents ___ in the Ohm's law formula
- capacitance
- voltage
- resistance
- amperage
14: R-11 has the greatest corrosive effect on
- Bronze
- Aluminum
- Copper
- Magnesium
15: A pressure vessel having an inside diameter of 6” or less shall be sufficient to withstand ____times the pressure of the saturation temperature of the refrigerant or ____times the critical pressure of the refrigerant, whichever is less.
- 6.6, 6.6
- 2.5, 3.0
- 3.0, 3.5
- 2.5, 2.5
16: Refrigerant restricted in 2004 but used for transition for decades:
- R-134A
- R-22
- R-11
- R-123
17: When an inspection is needed, how often must it be done?
- every 24 months
- every 18 months
- every 36 months
- annually
18: What instrument is used to measure very high resistance?
- meg ohmmeter
- ammeter
- voltmeter
- tape measure
19: How many gallons of water do you need per pound of ammonia?
- 10
- 50
- 1
- 100
20: The amount of heat required to raise the temperature of 1 lb of water 1F is?
- 1 Therm
- 1 BTU
- 1 Kelvin
- The rate of conduction
21: Low pressure chiller systems use what type of compressor?
- Centrifugal
- Scroll
- Screw
- Reciprocating
22: If the power element on an expansion valve should lose its charge, the valve would
- Stay open
- Under feed
- Close
- Over feed
23: Which of the following are considered inorganic refrigerants?
- R-717 and R-718
- 410A and R-407C
- R-500 and R-502
- None of the above
24: R-410A is classified as a ____ refrigerant on the safety matrix.
- A-2
- A-1
- B-2
- B-1
25: 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
- boost voltage
- pick up voltage
- run voltage
- lift voltage