How to Wire a 3-Prong Toggle Switch

Complete wiring guide from Goboll Electronics

Safety Warning

Always turn off power at the circuit breaker before working with electrical wiring. If you're not comfortable with electrical work, consult a licensed electrician.

What You'll Need

Tools

  • Wire strippers
  • Screwdriver set
  • Voltage tester
  • Wire nuts

Materials

  • 3-prong toggle switch
  • Electrical wire (if needed)
  • Wire nuts
  • Electrical tape

Understanding Your 3-Prong Toggle Switch

3-Prong Toggle Switch Diagram

Terminal Identification

COM (Common): Center terminal - always connected
NO (Normally Open): Connected when switch is ON
NC (Normally Closed): Connected when switch is OFF

Step-by-Step Wiring Guide

1

Turn Off Power

Switch off the circuit breaker and use a voltage tester to confirm power is off.

2

Identify Your Wires

Locate the hot (black), neutral (white), and ground (green/bare) wires in your electrical box.

3

Connect the Common Terminal

Connect the incoming hot wire (black) to the COM terminal of the switch.

4

Connect Load Wires

Connect your load wires to the NO and NC terminals based on your switching requirements.

5

Secure Connections

Tighten all terminal screws and wrap connections with electrical tape if needed.

6

Test the Installation

Turn power back on and test the switch operation to ensure proper functionality.

Common Wiring Configurations

Single Load Control

Single Load Wiring Diagram

Use COM and NO terminals for simple on/off control of one device.

Two Load Control

Dual Load Wiring Diagram

Use all three terminals to switch between two different loads.

Tips & Troubleshooting

Tips

  • • Always strip wires to the correct length
  • • Use wire nuts for spliced connections
  • • Label wires before disconnecting
  • • Check switch ratings match your load

Troubleshooting

  • • No power: Check circuit breaker
  • • Switch not working: Verify connections
  • • Intermittent operation: Tighten terminals
  • • Wrong operation: Check NO/NC wiring

Need Expert Help?

Goboll Electronics has been manufacturing high-quality switches since 1989. Our certified products meet international standards including UL, VDE, TUV, and CE.

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Yueqing City, China
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