Topics: All categories in the pool
1: A chiller entering and leaving temperature difference is?
- 20 degrees F
- 50 degrees F
- 10 degrees F
- 5 degrees F
2: How are refrigerant blends classified?
- Based on worst case fractionation
- Based on the oil used
- Blends don't have to be classified
- Based on best case Fractionation
3: Which creates more of a heat load?
- 70% RH
- 30% RH
- 90% RH
- 50% RH
4: What do you need to do when you install a new system?
- Document the superheat and subcooling reading
- Insulate the suction line before you take a superheat reading
- Add refrigerant
- Have it inspected
5: When must refrigeration system covered by the code be inspected?
- Upon installation
- Annually and when installed
- Annually
- Not required
6: Doors communicating with outside from a mechanical room must be?
- Steel, approved, weather-stripped
- Self-closing, approved, fire door
- Self-closing, aligned, fire door
- Self-closing, wooden, fire door
7: 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
8: If a refrigerant leaving the condenser is 94F and the condensing temperature is 105F, the subcooling is
- 9F
- 21F
- 29F
- 11F
9: R-410A is classified as a ____ refrigerant on the safety matrix.
- A-1
- B-2
- B-1
- A-2
10: 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.
- 2.5, 3.0
- 3.0, 3.5
- 6.6, 6.6
- 2.5, 2.5
11: 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
12: In an electrical circuit, what is potential measured in?
- Amps
- Ohms
- Herys
- Volts
13: A multi-evaporator refrigeration system uses what type of valve to maintain evaporating temperatures?
- Solenoid valve
- EPR valve
- EEV
- CPR valve
14: A low oil switch is typically
- automatic reset
- time-delay auto reset
- non used on semi-hermetic compressors over 10 ton capacity
- manual reset
15: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
- 99%
- 80%
- 75%
- 90%
16: What is the purpose of a surge capacitor on a contactor?
- to protect low voltage equipment
- to provide smoother start/stops
- to balance the sine waves
- to keep the contactor pulled in
17: Joints in piping for refrigeration containing parts must withstand temperatures of ___?
- 800F
- 1000F
- 600F
- 700F
18: 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
19: The proper location for an oil separator is between the
- receiver and metering device
- evaporator and compressor
- condenser and receiver
- compressor and condenser
20: Name a CFC refrigerant(s):
- R-11
- R-12
- R-123
- both a & b
21: _____ alloys shall not be used in contact with an halogenated refrigerants.
- Copper
- Zinc
- Magnesium
- Nickel
22: Pressure relief devices are marked with a ____________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- UV or UR
- UL and UR
- UM or UL
- UL and UM
23: Low ambient controls are used when
- economizers are used
- always
- on air conditioning systems only
- when systems run all year round
24: Refrigerant piping crossing an open space that affords passageway in any building shall not be less than _____ feet above the floor unless piping is located against the ceiling.
- 7.25'
- 8'4"
- 9.00'
- 7.00'
25: The location of a thermal bulb of a TXV affects
- subcooling
- the amount of liquid returning to the compressor
- the amount of liquid in the condenser.
- the amount of liquid refrigerant in the evaporator