Topics: All categories in the pool
1: 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
- 226 psig, 68 psig
- 257 psig, 77 psig
- 365 psig, 120 psig
- 455 psig, 185 psig.
2: What is the leaving chilled water set point for water chiller systems?
- 45F
- 55F
- 66F
- 38F
3: If a condenser is on a roof and the temperature is 35F and dropping the capacity
- decreases
- increases
- run as designed with low ambient controls
- doesn't change
4: R-410A can segregate in the system or chemically change its composition due to a leak.
- True
- False
5: The most common type of motor starter is
- delts-wye starter
- duel-winding starter
- across the line starter
- part winding starter
6: In a properly balanced system with valves open and properly adjusted, if the suction line is warm to the touch, its because of
- low head pressure
- not enough oil in the system
- oil in evaporator
- moisture in the system
7: What is used to check very low pressure?
- Hydrometer
- Hygrometer
- Manometer
- Velometer
8: What effect does the temperature of air have on humidity?
- warmer air holds more moisture then cooler air
- cooler air holds more moisture then warmer air
- air has no effect of humidity
- none of the above
9: The color code of a tank of ammonia is
- silver
- lavender
- white
- light green
10: When can 50/50 solder be used?
- in the low side
- in the high side
- liquid and suction lines
- none of the above.
11: Pressure vessels with an internal volume of 10 cubic feet or more
- shall use fusible plugs
- shall use pressure relief devices or fusible plugs
- shall use rupture discs or duel pressure relief valves
- shall use pressure relief devices
12: To determine the pump size needed for an open cooling tower system, the following must be known,
- GPM and friction head
- GPM and unbalanced head and friction head
- GPM and balanced head and friction head
- GPM, pipe size, and equivalent head.
13: Where must a refrigeration contractor's license number be displayed?
- Uniforms, checks, and invoices.
- Truck, office, every job, and on all equipment
- Trucks, license plates, and uniforms
- Trucks, invoices, and advertising
14: Suction valve unloaders afford an effective means of
- capacity control
- refrigerant control
- superheat control
- evaporator control
15: A chiller entering and leaving temperature difference is?
- 50 degrees F
- 10 degrees F
- 5 degrees F
- 20 degrees F
16: Usually dry bulb temperature is
- not important and shall be ignored
- same as wet bulb temperature
- higher than wet bulb temperature
- lower than dry bulb temperature
17: Group A2 refrigerants have a ______ toxicity rating than Group B1 refrigerants.
- higher
- lower
- there is no Group B1 refrigerants
- the same
18: R-410A is classified as a ____ refrigerant on the safety matrix.
- A-2
- B-2
- A-1
- B-1
19: Capacitors are rated in
- volt - amperes
- kelvins
- micro-farads
- megaohms
20: A start capacitor in series with a start winding will
- increase starting torque
- decrease the amp draw of the motor
- increase running efficiency
- increase the amp draw of the motor
21: A EPR valve is installed on what type of evaporators?
- plate evaporators
- high-temperature evaporators
- shell and tube evaporators
- low-temperature evaporators
22: Refrigeration piping before being buried shall be
- leak tested
- encased in pipe duct
- pressure tested
- All of the above
23: How does a centrifugal compressor create the pressure differential needed to move refrigerant through the system?
- Suction and discharge valves
- Nesting scrolls
- Fan-like action
- Rotating vanes
24: On a TXV, the purpose of an external equalizer is to?
- balance the evaporator load
- allow a greater adjustment spam
- Increase the pressure on the top of the power head diaphragm
- compensate for a pressure drop across the evaporator coil
25: Gauge pressure is
- Force of pressure above that of atmosphere
- Atmospheric pressure
- Absolute pressrue
- Barometric pressure