Earth Bondhon
Creators
Rojony Khatun Author
Rojony Khatun
CalculatorToolsProjectExpert
Reviewers
Małgorzata Koperska, MD Steven Wooding
Last updated: September 5, 2025

Relay in Lamp Wiring Diagram with Working and Installation Guide

🇺🇸
English
Default
🇪🇸
Español
Spanish
🇫🇷
Français
French
🇩🇪
Deutsch
German
Single phase Light

Single Phase LED Light

Energy-efficient LED light for single-phase supply

Single phase Light

Well Light Holder

Recessed light holder typically used in ceilings/walls

10A SP MCB

10A SP MCB

Single Pole Miniature Circuit Breaker, 10 Amp

2 Way Switch

8-pin Relay 220V AC

Electromechanical relay with 8-pin base, 220V AC coil

*Please note: These are affiliate links. I may make a commission if you buy the components through these links. I would appreciate your support in this way!

Relay in Lamp Wiring

Learn relay in lamp wiring diagram with step-by-step guide, working principle, installation process, testing, and safety tips for beginners.

relay in lamp wiring diagram

A lamp wiring diagram is a relay that is a type of electromagnetic switch, which can be used to switch a lamp on or off. The coil closes the lamp circuits safely and efficiently.

how to connect relay to lamp

The lamp wiring diagram depicts a relay to allow a lamp to be operated by a relay switch rather than by a regular switch. A relay is an electromagnetic switch that a low-power circuit can use to drive a high-power lamp. He has a relay with a coil and contacts. As soon as a current is passed through the coil, the magnetic field forms that closes the loops of the contacts and finishes the lamp circuit. This construction can be applied to automation, isolation, and remote control. In the case of wiring, the lamp is wired through the relay contact to the phase wire, and the coil is wired through a switch or control system. Both the lamp and the relay coil are in direct connection to the neutral.

Work / Installation (Inputs → Outputs)

  • Input: Control switch or sensor provides low-voltage input to the relay coil.
  • Output: Relay contacts control the lamp load.

steps:

  • Connect the phase wire from supply to the relay common terminal.
  • Connect the relay NO (Normally Open) terminal to the phase terminal of the lamp.
  • Connect the neutral directly to the lamp.
  • For relay coil, connect one side to phase through a control switch, and the other side to neutral.
  • When the switch is pressed, the coil energizes, closing the relay contacts and switching ON the lamp.

Testing and Final Adjustments

Check after wiring phase between the relay, neutral, directly to lamp, coil wiring. Set the control switch to on and supply on. The relay must switch on, and the lamp must light. Assuming that the relay does not click, consider the voltage rating of the coil. Tighten terminals; insulate connections. Test a few times to ensure the working of relay is working. To be robust, a relay with the appropriate rating of current and voltage to power the lamp should be used.

Frequently Asked Questions - Relay in Lamp Wiring:

What is a relay in lamp wiring?

It is an electromagnetic switch used to control a lamp circuit.

Why use a relay for lamp connection?

It allows low-power control of a high-power lamp safely.

Which relay terminal connects to the lamp?

The Normally Open (NO) terminal connects to the lamp.

What voltage is used for the relay coil?

Usually 5V, 12V, or 24V depending on the relay type.

Does the neutral connect to the relay?

Neutral connects to the lamp and one side of the relay coil.

Can relay control multiple lamps?

Yes, if the relay contact rating supports the load.

Is a relay safer than direct switch wiring?

Yes, it provides electrical isolation and protection.

Can I use a relay with LED bulbs?

Yes, LED bulbs can be controlled with a relay.

What is the common relay contact?

It is the input terminal that switches between NO and NC.

Where are relays used in lighting?

In automation, remote control, sensors, and safety systems.

Rojony Khatun

Rojony Khatun

CalculatorToolsProject

Rojony Khatun is the creator of a free online tools website designed to simplify everyday and engineering-related calculations for students, professionals, and hobbyists. The platform offers a wide variety of basic and advanced calculators across key categories, including Electrical Calculators, Electronic Calculators, and Time & Date Calculators, helping users solve problems quickly and accurately.