HVAC Wiring Diagram and Motor Questions

Basic Electricity is the largest domain on the NATE Core exam at 26%: symbols, field wiring, pictorial and ladder diagrams, motors, actuators and digital meters. Practice reading circuits and checking motors.

Take the timed NATE Core mock exam

50 questions on the 90-minute clock, weighted like NATE’s Core outline, with a score for every area and an explanation for every option.

Or try the free wiring and motors drill
  • 36 original wiring and motors questions, every option explained
  • Tested on: NATE Core, NATE HVAC Support Technician
Free sample · Question 1 of 3Wiring and motors

A run capacitor rated 45 µF ±6% measures 37 µF. What should be done?

Choose the best answer

What our wiring and motors questions cover

  • Thermostat terminals (R, C, W, Y, G) and the 24-volt control circuit
  • Symbols, field wiring diagrams, pictorial diagrams and ladder diagrams, including sequence of operation
  • Single-phase motors: PSC, shaded-pole, start capacitors and potential relays, compressor terminal readings
  • Three-phase motors: rotation and voltage balance; ECM variable-speed blowers; damper actuators
  • Meters: voltage, resistance and continuity, capacitors, true RMS, millivolts and microamps
  • Nameplates: MCA, maximum fuse or breaker, LRA and choosing a replacement motor
Line drawing of a condensing unit control panel with a contactor and a dual run capacitor, a condenser fan motor beside it and a bundle of thermostat wires

This list is our own summary, written for practice. NATE publishes the full topic lists in its Knowledge Areas of Technician Expertise (KATEs).

Drill wiring and motors, then sit the full NATE Core exam

Take the timed NATE Core mock exam

50 questions on the 90-minute clock, weighted like NATE’s Core outline, with a score for every area and an explanation for every option.

Or try the free wiring and motors drill

Ideas the questions test most

  1. Compressor windings: Common to Run is lowest, Start to Run is highest, and C–R + C–S = R–S.
  2. Swap any two leads to reverse a three-phase motor.
  3. Ladder diagrams show switches first and one load per rung.
  4. Measure voltage in parallel; measure resistance with the power off.
  5. Size wire from MCA and protection from the maximum fuse or breaker rating.

Start the free wiring and motors drill · NATE Core practice test · NATE HVAC Support Technician practice test

Common questions

What is in the Basic Electricity domain of the NATE Core exam?

The Core KATE lists symbols, field wiring diagrams, pictorial diagrams, schematic (ladder) diagrams, single-phase motors, three-phase motors, variable-speed motors (ECM), actuator motors and digital electrical meters. It is 26% of the exam, about 13 of 50 questions.

Do I need to read wiring diagrams for the NATE Support Technician exam?

The Support Technician KATE covers basic electricity, meters, field wiring and thermostats at a more fundamental level than Core. Our Support Technician mock draws its electrical questions from both electrical topics at the entry and intermediate levels.

Take the timed NATE Core mock exam

50 questions on the 90-minute clock, weighted like NATE’s Core outline, with a score for every area and an explanation for every option.

Or try the free wiring and motors drill

More HVAC topics

Exam format and outline checked November 2026 on natex.org: NATE: Ready-to-Work and HVAC Support Technician certificates · NATE Ready-to-Work KATE (PDF) · NATE HVAC Support Technician KATE (PDF) · NATE Core Exam KATE (PDF) · NATE: Frequently asked questions. NATE has not announced a change to this outline.

NATE is a mark of North American Technician Excellence, Inc. Game Assessment Prep is an independent practice site, not affiliated with or endorsed by NATE. Every question is original; none is taken from NATE exams, NATE study guides or another prep provider.