HVAC Technician Core (NATE-style) — Practice Exam
Electrical: controls: practice questions
Our HVAC Core (NATE-style) bank has 8 questions on this topic. Here are 4 of them with answers; the full mock exam draws from every topic, like the real one.
Question 1
What is the function of a fuse or circuit breaker?
- To open the circuit on overcurrent and protect wiring and equipment
- To start motors
- To store energy
- To raise voltage when a motor starts
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A. To open the circuit on overcurrent and protect wiring and equipment — Size per the nameplate's maximum overcurrent protection.
Question 2
What is a relay?
- A transformer
- A motor winding
- An electrically operated switch using a small current to control a larger one
- A fuse that resets itself after it trips
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C. An electrically operated switch using a small current to control a larger one — Relays are used for fans and controls.
Question 3
What does a furnace limit switch protect against?
- High refrigerant pressure
- Low gas pressure at the burner manifold during startup
- High humidity
- Overheating of the heat exchanger
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D. Overheating of the heat exchanger — It opens on high temperature.
Question 4
What does a contactor do in an air conditioner?
- Stores energy for startup
- Measures temperature
- Uses a low-voltage coil to switch line voltage to the compressor and fan
- Stores energy for compressor startup
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C. Uses a low-voltage coil to switch line voltage to the compressor and fan — The thermostat energizes the 24 V coil.