SCRIPT 2026 COMPREHENSIVE QUESTIONS
WITH SOLUTIONS GRADED A+
⩥ What are the three basic types of wiring diagrams used in the HVACR
trade? Answer: 1. The ladder diagram
2. The pictorial diagram
3. The installation diagram
⩥ Describe the characteristics of a ladder diagram Answer: 1. Provides
the most helpful information for electrical troubleshooting
2.The intention of the overall schematic is to show how the circuit
functions not how it actually looks.
⩥ Describe the characteristics of a pictorial diagram Answer: 1. Usually
includes drawings that more closely resemble the components
themselves rather than the symbols.
2. Provides the best indication of the actual positions of the components
in the equipment or control panel.
⩥ Describe the characteristics of an installation diagram Answer: 1.
Used primarily By the person installing equipment
2. It normally only shows what the terminal board connections are and
may or may not include any internal wiring of the unit
,3. Field wiring Generally represented as Dashed lines.
4. Thicker lines represent line voltage wiring(120/240 V)
5. Thin lines represent low-voltage control wiring
⩥ What is a switch? Answer: A switch is a device that interrupts power
to the load. It may be manually or automatically activated by pressure,
temperature or it may be an electrically controlled switch
⩥ What is a load? Answer: A load is a device that consumes power and
converts it into some other form of energy
⩥ Describe the side-by-side arrangement four wire diagrams Answer:
Usually arranges motors and other power consuming components on the
right side of the diagram called the "load" side. The switches and other
controllers are placed on the left side of the diagram called the
"line"side.
⩥ Describe the up and down schematic arrangement Answer: This type
of arrangement divides the schematic in to high-voltage and low-voltage
sections. Normally the high voltage section is placed on the top and the
low voltage is placed on the bottom of the diagram.
⩥ What are the two basic configurations used in schematics? Answer:
Side by side arrangement and up and down arrangement
, ⩥ A particular right triangle that has two equal sides. This is a? Answer:
45°- 45°-90°right triangle
⩥ Which of the following is typically represented by the two lines on the
sides of a diagram? Answer: Each leg of the line or low voltage power
⩥ To change the direction of rotation of a three phase motor, it is
necessary to? Answer: Reverse any two of the motor leads
⩥ The overload protection of a 10a and ma inputs of a digital used in
HVAC work are? Answer: Always the same
⩥ As a general rule, a continuity check using an ohmmeter shows
continuity by a reading of? Answer: At zero or a specific resistance
⩥ How is a voltmeter connected for taking a reading? Answer: In
parallel with the voltage to be measured
⩥ A service company was blasted in a news article the employees were
briefed in a company meeting and the majority of them nothing was
done wrong and supported the company. The employees shown there
were? Answer: Loyal
⩥ The federal agency that oversees the transportation of pressurized
cylinder is? Answer: DOT