California State License No. 989035Residential & Commercial Electrical Contractor

Haik Electric • Electrical Education

Understand How Electrical Circuits Work

Professional interactive demonstrations developed to explain electrical principles clearly and responsibly. These lessons are educational overviews—not installation instructions.

Lesson 1

120-Volt Branch-Circuit Concept

Single-Pole Switch Controlling One Luminaire

Operate the switch to follow conventional current from the energized line, through the closed switch and luminaire, then back to the source on the grounded conductor (neutral).

Circuit statusOPEN • LIGHT OFF
Interactive single-pole lighting circuit All conductors are visible. Line feeds the upper-right switch terminal, switched line feeds the luminaire, neutral returns from the luminaire to source N, and equipment grounding bonds both devices. SOURCESINGLE-POLE SWITCHLUMINAIRE L N G LINE / HOTNEUTRALEQUIPMENT GROUND ONOFF LINELOADGROUND OPEN HOT / CENTER CONTACTNEUTRAL / THREADED SHELLLIGHTING OUTLET / LUMINAIRE SWITCHED LINEGROUNDED CONDUCTOR (NEUTRAL) • RETURN TO SOURCEEQUIPMENT GROUNDING CONDUCTOR • NO NORMAL LOAD CURRENT

Select the switch to close the circuit and energize the luminaire.

1

Line remains energized

The ungrounded conductor supplies the upper-right LINE terminal. Opening the switch does not de-energize its line side.

2

The switch controls the load

Closing the visible contact blade completes the path between LINE and LOAD and energizes the luminaire.

3

Neutral completes the circuit

Normal load current returns from the luminaire to source N on the grounded conductor—not on equipment ground.

Lesson 2

Two Independent Branch-Circuit Loads

Separate Switches Controlling a Light and Fan

The left switch controls only the luminaire. The right switch controls only the fan. Press the top or bottom of either illustrated switch to operate that load independently.

Load statusLIGHT OFF • FAN OFF
Two single-pole switches independently controlling a light and fan All conductors and terminal connections are visible. Red line power branches to the upper-right line terminal of each switch. Orange switched power serves the light, yellow switched power serves the fan, white neutral connects directly to both loads, and green equipment grounding bonds all devices. SOURCELIGHT SWITCHFAN SWITCHLOADS NNEUTRAL LLINE / HOT G ☀OFF LIGHT SWITCHLINELOAD OFF FAN SWITCHLINELOAD LIGHT FAN LINE FEEDS BOTH SWITCHESORANGE — LIGHT LOADYELLOW — FAN LOADEQUIPMENT GROUND • NO NORMAL LOAD CURRENT

Operate the illustrated switches: top = ON, bottom = OFF.

☀ LIGHT OFF✦ FAN OFF
1

Light switch

The left switch closes only the orange switched-line path to the luminaire.

2

Fan switch

The right switch closes only the yellow switched-line path to the fan.

3

Shared supply and return

Line is properly branched to both switches. Each load has a direct neutral return; equipment ground carries no normal load current.

Lesson 3

Multi-Location Lighting Control

Two 3-Way Switches Controlling One Luminaire

Operate either 3-way switch to change the state of the light. Each switch connects its common terminal to one of two traveler conductors; a complete path exists when both switches select the same traveler.

Circuit statusCLOSED • LIGHT ON
Interactive three-way lighting circuit Line connects to the common terminal of the first 3-way switch. Two visible traveler conductors run between the switches. The common terminal of the second switch feeds the luminaire, neutral returns directly to source, and equipment grounding bonds both switches and the luminaire. SOURCE3-WAY SWITCH A3-WAY SWITCH BLUMINAIRE NNEUTRAL LLINE / HOT G 3WAYTOP COMMONTRAVELER 1TRAVELER 2 3WAYTOP TRAVELER 1TRAVELER 2COMMON LIGHT TRAVELER 1TRAVELER 2EQUIPMENT GROUND • NO NORMAL LOAD CURRENT

Operate either illustrated 3-way switch. There is no fixed ON or OFF position—the result depends on both switches.

SWITCH A: TOPSWITCH B: TOP
1

Line enters the first common

The ungrounded supply conductor connects to the dark-colored common terminal of Switch A.

2

Two traveler paths

Each switch transfers its common connection between Traveler 1 and Traveler 2. The travelers are not neutral conductors.

3

Second common feeds the light

When both switches select the same traveler, the complete path energizes the luminaire; operating either switch opens that path and selects the other traveler.

Lesson 4

Three-Location Lighting Control

Two 3-Way Switches and One 4-Way Switch

The two 3-way switches occupy the ends of the circuit. The 4-way switch is installed between their traveler pairs and alternates between straight-through and crossed traveler connections. Operating any switch changes the light state.

Circuit statusCLOSED • LIGHT ON
Interactive four-way lighting circuit Line feeds the common of the first 3-way switch. One traveler pair passes through a 4-way switch to the traveler terminals of the second 3-way switch. The second common feeds the luminaire, neutral returns directly to source, and equipment grounding bonds all devices. SOURCE3-WAY A4-WAY3-WAY BLIGHT NNEUTRAL LLINE / HOT G 3WAYTOP COMMON 4WAYSTRAIGHT 3WAYTOP COMMON LIGHT TRAVELER 1TRAVELER 2EQUIPMENT GROUND • NO NORMAL LOAD CURRENT

Operate any switch. The 4-way switch reverses the relationship between the two traveler conductors.

3-WAY A: TOP4-WAY: STRAIGHT3-WAY B: TOP
1

3-way switches terminate the circuit

Line connects to the common of the first 3-way switch. The common of the second 3-way switch feeds the luminaire.

2

The 4-way switch manages travelers

The intermediate device has four traveler terminals and connects the pairs either straight through or crossed. It has no common terminal.

3

Any location changes the light

Operating any one switch changes the continuity of the selected traveler path and therefore changes the state of the luminaire.

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