Electrical

Question 1

What are the two types of electric circuits in a home?

Answer 1

Power circuits (house voltage) - heat, light, motion
Control circuits (low voltage) - regulate furnaces, water heaters, and appliances

Question 2

A circuit is composed of three parts:

Answer 2

Source (power plant), path (wires), load (device)

Question 3

Switches are used to:

Answer 3

open and close a circuit

Question 4

Series circuits

Answer 4

Have only on continuous path
Voltage drops across each load
Not used to connect multiple loads

Question 5

Parallel circuits

Answer 5

Have multiple paths, each containing a load

Most home circuits are wired in parallel to ensure consistent voltage to all loads

Question 6

Control circuits provide precise control of energy systems. What are their components?

Answer 6

Transformer - reduces voltage down to 24V
Controller - sense environmental conditions or user input
Control element - pump, gas valve, burner, fan, etc

Question 7

What is Ohm’s Law?

Answer 7

E = I x R
Voltage = Current x Resistance

Question 8

What is voltage?

Answer 8

Electrical pressure or force measured in volts

Question 9

What is current?

Answer 9

Flow of electrons measured in amps

Question 10

What is resistance?

Answer 10

Opposition to current flow measured in Ohms. Produces work

Question 11

What’s the Power Law?

Answer 11

Current x Voltage = Power in Watts

Question 12

Describe how electricity gets from power lines to a house.

Answer 12

Service drop extends from the utility pole to the electrical meter of the house (2 120 V hot wires, one neutral structural wire).
Feeder wires connect the meter to the panel box.
A grounding wire connected to the panel metal is connected to the neutral feeder and attached to a copper grounding rod driven into the ground.

Question 13

What are the two types of circuits in a house?

Answer 13

Branch circuits - serve multiple loads such as lights, fans, outlets, etc.
Appliance circuits - serve a single appliance each like refrigerator, water heater, heating system, etc.

Question 14

What’s a short circuit?

Answer 14

The flow of electricity through a circuit that does not contain a load or contains a very low resistance load. When resistance drops near zero, max current is produced.

Question 15

Short circuits occur because of:

Answer 15

Sticking something in an outlet, disconnected wiring, worn insulation, damaged cords, etc

Question 16

A branch circuit wired with 12-2 wire should have a max ___ amp breaker that protects the wire from overheating if too much current flows.

Answer 16

20

Question 17

Circuits wired with 14-2, or older house branch circuits, should have a max ___ amp breakers.

Answer 17

15

Question 18

What’s a fault circuit?

Answer 18

The accidental flow of electricity through a stray circuit that is not part of the electrical system of the house. Common in presence of water.

Question 19

What’s a GFCI?

Answer 19

A Ground Fault Circuit Interrupter protects outlets in wet locations. It trips instantly if it detects any mismatch in current between the hot wire and the neutral wire, indicating a fault.

Question 20

What’s the top left hole in an outlet?

Answer 20

Neutral

Question 21

What’s the top right hole in an outlet?

Answer 21

Hot

Question 22

What’s the lower center hole in an outlet?

Answer 22

Ground

Question 23

What are some common electrical problems?

Answer 23

Unlabeled panel, overloaded receptacles, oversized fuses/breakers, reversal of hot/neutral, missing GFCIs, sharp screws in panel cover, ungrounded outlets and metal, pipes not grounded, etc.