Topics: All categories in the pool
1: A 50 VA control transformer with a 25 volt control output would be rated for _________ amps.
- 2.5
- There isn't enough information to answer.
- 1250
- 2
2: What must be done to refrigerant pipes before being buried?
- Leaked checked
- Encased
- Certified
- Coated
3: On a TXV, the purpose of an external equalizer is to?
- compensate for a pressure drop across the evaporator coil
- allow a greater adjustment spam
- Increase the pressure on the top of the power head diaphragm
- balance the evaporator load
4: Low pressure systems have what kind of compressor?
- Rotary
- Centrifugal
- Scroll
- Reciprocating
5: A “U” or “UM” marking a on a nameplate of a pressure vessels signifies compliance with Section VIII of
- the ASME Boiler and Pressure Vessel Code
- Section 11.3.1.5 ASHRAE 15 Standard
- the ANSI Standard 10.7.2
- both the ANSI Standard 10.7.2 and ASHRAE 15 Standard 11.3.1.5
6: R22 and 410A operate at the same range of condensing and evaporating temperatures
- true
- false
7: The boiling point of a refrigerant is based on
- Temperature
- Heat content
- a pressure-temperature relationship
- None of the above.
8: A water regulating valve opens when
- the compressor is on
- when the power is on
- the head pressure rises
- when the power is on there is an overcharge of refrigerant
9: R-12 is
- trichlorofluoromethane
- dichlorodifluoromethane
- dichloromethane
- dichlorofluoromethane
10: What is the purpose of suction/discharge traps?
- to ensure proper oil return to the compressor
- to keep oil inside the evaporator for proper oil return to the compressor
- to keep oil inside of the accumulator for proper return to the compressor
- all of the above
11: When a refrigeration or air conditioning system is installed
- a field inspection shall be made before it is put into service
- it shall be approved by the owner for proper operation.
- the form of certificate shall be authorized by the Department of Pubic safety
- it shall not be operated below prescribed pressures
12: Indirect systems using Group II refrigerants
- shall be used in refrigeration system less than 1,000 lbs
- shall be used in refrigeration system in excess of 1,000 lbs
- shall be used for mechanical equipment only
- shall have all refrigerant containing parts except piping, installed in a Class T machine room
13: 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
14: How are a compressor and condenser fan wired?
- series
- parallel
- series-parallel
- parallel-series
15: What refrigerant is an inorganic compound?
- R-132A
- R-410A
- R-22
- Ammonia
16: Low pressure chiller systems use what type of compressor?
- Scroll
- Centrifugal
- Reciprocating
- Screw
17: When must refrigeration system covered by the code be inspected?
- Not required
- Annually
- Annually and when installed
- Upon installation
18: A solder joint melts at temperatures of
- 1,200F to 1,500F
- 400F to 800F
- less than 400F
- 600F to 900F
19: What is a megaohm meter?
- An electric meter used by electricians to test large 3-phase blower motors for the correct rotation
- Is an electric meter that measures extremely low resistance valves by sending high DC voltage signal into the object being tested.
- An electric meter that measures very high resistance values by sending a low voltage AC signal into the object being tested
- An electric meter that measures very high resistance values by sending a high DC voltage signal into the object being tested
20: The test pressure applied to the high side of each factory-assembled refrigerating system shall be at least equal to the design pressure of
- the low side
- the high side
- 2.5 times the design pressure
- the aggregate of the high side and low side
21: R-22 is classified as a ____ refrigerant on the safety matrix.
- B-1
- A-1
- B-2
- A-2
22: 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 where the refrigerant comes in contact with the space refrigerated
- is a self-contained complete factory made and tested system
23: Ammonia systems use ____ pressure to adjust oil pressure
- liquid
- air
- discharge
- stream
24: When energized, a normally open relay will be
- noisy
- depends on the type and class of the relay
- open
- closed
25: Refrigerant is metered into the evaporator on a large centrifugal chiller thru the
- low side of the system
- high side float assembly
- cap tube
- none of the above