Topics: All categories in the pool
1: A plug containing an alloy that will melt at a specific temperature to relief pressure is a
- fusible plug
- relief plug
- fusion plug
- rupture plug
2: A chilled water pump's suction gauge reads 10 psig. The discharge gauge reads 48 psig. What is the head in feet the pump is working against?
- 38
- 58
- 96
- 88
3: Ammonia systems use ____ pressure to adjust oil pressure
- discharge
- liquid
- stream
- air
4: Where is an EPR valve located on a multi-evaporator system?
- Suction line of the coolest evaporator
- Suction line at the compressor
- Suction line prior to the accumulator of the lowest temperature system
- Suction line of the warmest evaporator
5: What is the refrigerant dichlorodifluoromethane?
- R-22
- R-134A
- R-123
- R-12
6: The low pressure oil safety switch
- resets itself automatically
- must be reset manually
- never trips
- resets itself after the time delay has terminated
7: If your suction line is warmer than the room temperature, this may indicate
- an over charge
- a low charge
- below normal superheat
- plugged air filter
8: What is the refrigerant chlorodifluoromethane?
- R-123
- R-134a
- R-22
- R-12
9: What will occur if the strong solution in an absorption chiller becomes too strong?
- The machine will stop cooling and solution will crystallize
- The machine will stop cooling and the solution will evaporate.
- The machine will cool excessively as the solution crystallizes.
- The machine will cool excessively as the solution evaporates
10: Crankcase heaters are energized
- when the compressor is off
- while the compressor is running
- to prevent compressor freeze-up
- to allow easy compressor start-up
11: The best way to detect ammonia in brine is
- potassium of line
- carbonation of soda
- CO2 gas
- nessler regaent
12: Lithium-bromide, Li-Br, is best characterized as a
- sugar
- salt
- sand
- soil
13: Increasing superheat will do what to your frost line?
- Could either increase or decrease depending on the load conditions
- Decrease
- Nothing
- Increasae
14: 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 can not enter the occupied space
- is such that a leak of refrigerant from a failed connection will enter the occupied space
15: Group A3 refrigerants have a ______ flammability rating than Group B1 refrigerants
- lower
- higher
- the same
- there is no Group B1 refrigerants
16: A R-410A system running with a condensing temperature of 110F and 50F evaporator temperature will read pressures of ___ on the high side and ___ on the low side
- 455 psig, 185 psig.
- 257 psig, 77 psig
- 365 psig, 120 psig
- 226 psig, 68 psig
17: Which of the following controllers would you expect to be most sensitive to temperature changes?
- aquastat
- immersion controller
- line voltage t-stat
- low voltage t-stat
18: An evaporator coil located near heating coil shall have a pressure-relief device installed within ______ inches of the evaporator.
- 36
- 24
- 18
- 48
19: What is the state of the refrigerant leaving the evaporator?
- low temperature superheated vapor
- a high temperature superheated vapor
- a low temperature subcooled liquid
- a high temperature subcooled liquid
20: _____ alloys shall not be used in contact with an halogenated refrigerants.
- Copper
- Magnesium
- Nickel
- Zinc
21: Machinery rooms must be vented to ______?
- unoccupied spaces
- basement
- outdoors
- neutralizing tank
22: Pressure is the equivalent of
- force per unit area
- force times area
- force
- area times force
23: Suction valve unloaders afford an effective means of
- capacity control
- evaporator control
- superheat control
- refrigerant control
24: One atmosphere equals
- 29.4
- 0 psig
- 14.7
- 0 psia
25: When an electronic bridge is in balance the bridge output will be
- 0 volts
- 1 volt
- 15 volts
- .01 volts