Relays are an essential component in any electrical circuit. They allow electrical circuits to be controlled by a separate low-power signal, which makes it possible to use a switch to control a high-power device. A 12v relay wiring diagram is a guide that shows you how to connect a 12v relay to your electrical system to control various devices such as lights, fans, motors, and more. In this article, we’ll cover everything you need to know about 12v relay wiring diagrams, including what they are, how they work, and how to wire them correctly.
What is a 12v Relay and How Does it Work?
A 12v relay is an electromagnetic switch that is commonly used in automotive and marine applications. It consists of a coil, a set of contacts, and a metal armature that moves when the coil is energized. When the coil is energized, it creates a magnetic field that pulls the armature towards the contacts, closing the circuit and allowing current to flow through the contacts. When the coil is de-energized, the armature returns to its resting position, opening the circuit and stopping the flow of current.
There are two types of 12v relays: Normally Open (NO) and Normally Closed (NC). When the relay is in its resting state, a NO relay is open, while an NC relay is closed. When the coil is energized, the opposite happens: a NO relay is closed, while an NC relay is open.
12v relays are essential for controlling high-current devices using low-current switches. For example, you can use a 12v relay to turn on a set of lights when you flip a switch, or to turn off a fan when a temperature sensor detects that the temperature has reached a certain level.
How to Wire a 12v Relay
Wiring a 12v relay is a straightforward process that requires only a few basic tools and some electrical knowledge. Here’s a step-by-step guide on how to wire a 12v relay:
Step 1: Gather Your Materials
The first step in wiring a 12v relay is to gather all the materials you’ll need. Here’s a list of what you’ll need:
| Qty. | Item |
| 1 | 12v relay |
| 1 | 12v power supply |
| 1 | Switch |
| 1 | Device to control (e.g. lights, fan, motor) |
| 1 | Fuse and fuse holder |
| Assorted | Wire connectors, soldering iron, wire strippers, electrical tape, etc. |
Step 2: Connect the Power Supply
The next step is to connect the power supply to the relay. To do this, connect the positive (+) wire from the power supply to terminal 30 on the relay, and connect the negative (-) wire from the power supply to a ground point on your vehicle.
Step 3: Connect the Switch
The next step is to connect the switch to the relay. To do this, connect one side of the switch to a positive (+) wire on your vehicle, and connect the other side of the switch to terminal 86 on the relay.
Step 4: Connect the Device to Control
The next step is to connect the device you want to control to the relay. To do this, connect one side of the device to a positive (+) wire on your vehicle, and connect the other side of the device to terminal 87 on the relay.
Step 5: Add a Fuse
The last step is to add a fuse to the circuit to protect against electrical faults. To do this, insert a fuse into a fuse holder and connect the fuse holder to the positive (+) wire between the power supply and the relay.
FAQs about 12v Relay Wiring Diagrams
1. What is the maximum current that a 12v relay can handle?
The maximum current that a 12v relay can handle depends on the specific model you are using. Most relays can handle between 30A and 40A, but you should check the specifications of your relay before using it to control a high-current device.
2. Can I use a 12v relay to control multiple devices?
Yes, you can use a 12v relay to control multiple devices by connecting them in parallel. Make sure that the total current draw of all the devices does not exceed the maximum current rating of the relay.
3. Can I use a 12v relay in a 24v system?
No, you should not use a 12v relay in a 24v system. The coil of the relay is designed to operate at a specific voltage, and using it in a system with a different voltage can cause it to malfunction or fail. Instead, use a relay that is designed specifically for the voltage of your system.
4. Why do I need a fuse in my 12v relay circuit?
A fuse is essential in any electrical circuit to protect against electrical faults such as short circuits and overloads. Without a fuse, an electrical fault can cause serious damage to your vehicle’s electrical system, or even start a fire.
5. Can I use a 12v relay to control AC devices?
No, you should not use a 12v relay to control AC devices. 12v relays are designed to control DC devices, and using them to control AC devices can cause them to malfunction or fail. Instead, use a relay that is designed specifically for AC devices.
Conclusion
Wiring a 12v relay is a simple process that can be done by anyone with basic electrical knowledge. By using a 12v relay, you can control high-current devices using low-current switches, making it easy to control everything from lights to motors. We hope that this guide has been informative and has helped you understand everything you need to know about 12v relay wiring diagrams.
