CAR Blueprint Reading & Interpretation 2 — Questions and Answers
Question 1: On an appliance wiring diagram, a dashed line typically represents which type of connection?
- A high-voltage circuit
- A factory-installed wire
- A field-installed or optional wire (Correct answer)
- A ground fault connection
Correct answer: A field-installed or optional wire
Dashed lines on wiring diagrams indicate field-installed or optional wiring that is not part of the factory assembly.
Question 2: What does the symbol 'M' inside a circle typically represent on an appliance schematic?
- Meter
- Motor (Correct answer)
- Manual switch
- Magnetic relay
Correct answer: Motor
A circle containing the letter 'M' is the standard schematic symbol for an electric motor.
Question 3: When reading a refrigerator blueprint, the evaporator and condenser coils are distinguished primarily by their location relative to which component?
- The compressor (Correct answer)
- The thermostat
- The fan motor
- The defrost heater
Correct answer: The compressor
The evaporator coil is located on the low-pressure side before the compressor, while the condenser coil is on the high-pressure side after it.
Question 4: A CAR technician sees '120V/60Hz' noted near a component on a blueprint. What does '60Hz' specify?
- The component's wattage rating
- The AC frequency of the power supply (Correct answer)
- The component's impedance
- The cycle time of a timer
Correct answer: The AC frequency of the power supply
60Hz denotes the frequency of the alternating current supply, which is the US standard.
Question 5: On a parts breakdown diagram for a washing machine, exploded-view drawings are used primarily to:
- Show internal wiring paths
- Illustrate the assembly sequence and part relationships (Correct answer)
- Indicate refrigerant flow direction
- Display electrical load ratings
Correct answer: Illustrate the assembly sequence and part relationships
Exploded-view drawings separate components spatially to clearly show how parts fit together and the order of assembly.
Question 6: Which line type on a piping-and-instrumentation diagram (P&ID) for a refrigeration system indicates insulated piping?
- A solid single line
- A double parallel line (Correct answer)
- A dashed line with circles
- A zigzag line
Correct answer: A double parallel line
Insulated piping is conventionally shown as two parallel lines representing the pipe wall and the insulation layer.
Question 7: A blueprint legend shows a triangle symbol pointing downward near a drain line. This most likely indicates:
- A pressure relief valve
- A floor drain or condensate drain outlet (Correct answer)
- A refrigerant charge port
- A high-voltage junction
Correct answer: A floor drain or condensate drain outlet
A downward-pointing triangle near a drain line in appliance blueprints conventionally marks a condensate or floor drain outlet.
CAR Blueprint Reading & Interpretation 2
On an appliance wiring diagram, a dashed line typically represents which type of connection?