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Hvac pmi practice questions

21 questions from the diesel and heavy truck practice test.

Hvac pmi practice test

10 questions, graded as you go, with the reason for every answer. No sign-up.

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Sample questions

In a system with a thermostatic expansion valve (TXV), where is the receiver-drier located?

  1. In the low-side suction line between the evaporator and compressor
  2. In the discharge line between the compressor and the condenser
  3. Inside the evaporator case, ahead of the blower motor
  4. In the high-side liquid line between the condenser and the TXV
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D. In the high-side liquid line between the condenser and the TXV

The receiver-drier stores liquid refrigerant and holds the desiccant on the high side after the condenser. The component in the suction line after the evaporator is an accumulator, used with orifice tube systems.

Reference: ASE T7 Heating, Ventilation and Air Conditioning task list, A/C system components

What does a thermostatic expansion valve use to decide how much refrigerant to meter into the evaporator?

  1. The pressure in the compressor discharge line
  2. The temperature of the evaporator outlet
  3. The temperature of the engine coolant
  4. The speed of the compressor clutch
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B. The temperature of the evaporator outlet

The sensing bulb on the evaporator outlet opens the valve when the outlet warms (the evaporator needs more refrigerant) and closes it when the outlet gets cold, keeping liquid from reaching the compressor.

Reference: ASE T7 Heating, Ventilation and Air Conditioning task list, A/C system components (TXV)

Under EPA rules, what is required of a technician who services motor vehicle A/C systems for pay?

  1. Section 609 certification and use of approved recovery equipment
  2. A state emissions inspector license for the vehicle class
  3. Section 608 Type I certification, which covers small appliances
  4. No certification, provided the refrigerant is R-134a
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A. Section 609 certification and use of approved recovery equipment

Section 609 of the Clean Air Act requires anyone repairing or servicing motor vehicle A/C for compensation to be trained and certified through an approved program and to use approved recover/recycle equipment. Section 608 covers stationary equipment.

Reference: Clean Air Act Section 609; 40 CFR Part 82 Subpart B

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