Topics: All categories in the pool
1: R-11 has the greatest corrosive effect on
- Magnesium
- Aluminum
- Bronze
- Copper
2: Thermodynamics is the branch of science that deals with
- energy due to motion
- heat energy
- state of energy
- molecular therory
3: System design pressures must take into consideration, not only, pressures found during normal operation but also what?
- When it's cold out
- When there is a malfunction on the high side
- When its warm out
- All of the above
4: By using nitrogen within a pipe during brazing operation,
- The explosion hazard is confined
- Exterior scale formation is minimized
- Discoloration is prevented
- Copper oxide formation is prevented
5: The formula for Pure Power in a resistance circuit is
- Watts = volts X amps
- Watts X amps.
- Kw = volts X amps
- Watts X power factor
6: A direct system
- is one which encloses a separate body of evaporative refrigerant
- is on where brine is cooled & circulated to the space refrigerated
- is a self-contained complete factory made and tested system
- is where the refrigerant comes in contact with the space refrigerated
7: Color is important in oil because
- it indicates the viscoisty.
- allows you to see into crankcase
- it makes sight glasses easy to read
- can tell us something about the refining of oil
8: How would you know if there was a loss of crankcase pressure?
- oil will thin out
- oil level will rise
- oil will thicken
- oil will foam
9: Watt's Law indicates Volts X Amps = _________.
- Resistance
- Watts
- Current
- Ohms
10: An electrical circuit has a 208V power supply and draws 47 amps total, What would be the wattage of the circuit
- 9.776 watts
- .9776 watts
- 977.6 watts
- 9,776 watts
11: What instrument is used to measure very high resistance?
- tape measure
- meg ohmmeter
- voltmeter
- ammeter
12: A single pole-double throw switch uses how many wires?(excluding the ground)
- 4
- 2
- 3
- 5
13: Before replacing a seized compressor, the _______ should be determinded.
- designed head pressure
- current draw
- type of refrigerant
- cause of seizure
14: A run capacitor is wired in series with the _____ windings.
- start
- start capacitor
- run
- common
15: Evaporators within 18" of a heating coil must be equipped with a
- pressure relief device
- zone valve
- high limit control
- low limit control
16: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
- 550 lbs
- 660 lbs
- 55 lbs
- 330 lbs.
17: Cooling tower lowers condenser water temp by
- evaporative cooling
- running water thru a secondary heat exchanger
- running fans at 100%
- condensation
18: 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-11
- Flush with ammonia
- Flush with R-718
19: Capacity control on an absorption system is typically accomplished by varying the
- speed of the chilled water circulatory pump
- pressure setting on the system's rupture disc
- speed of the condenser water circulator pump
- rate at which heat is supplied to the generator
20: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
- Make sure its compatible, notify owner, and notify AHJ.
- you can never change refrigerants
- Place sign, check for leaks, and insulate suction line
- Nothing must be done
21: When an A/C system is excessively low on refrigerant
- it can become contaminated with water
- there can be nuisance trip outs
- the suction line may be too hot to touch
- All of the above
22: Pressure vessels nameplate markings must be compliant with the
- ASHRAE 34 Standards
- CMR-588 & CMR-528
- ASME Boiler and Pressure Vessel Code
- All of the Above
23: All low-pressure chillers use which type of compressor?
- Reciprocating
- Scroll
- Centrifugal
- Rotary
24: How many closing forces operate a thermostatic expansion valve?
- 4
- 3
- 2
- 1
25: Humidity can be sensed with
- human hair
- pressure bellows
- thermometer
- bimetal