Understanding a 5 blade relay wiring diagram is crucial for anyone working with automotive electrical systems or other DC power applications. These relays act as electrically operated switches, allowing a low-current circuit to control a high-current circuit. A 5 blade relay wiring diagram specifically outlines the connections for a double-pole, double-throw (DPDT) relay, offering more versatility than simpler 4-pin relays.
What is a 5 Blade Relay Wiring Diagram and How is it Used?
A 5 blade relay wiring diagram illustrates the internal connections and external hookups for a specific type of relay. This relay, often called a DPDT relay, has five terminals: a common input (or common output), two normally closed (NC) terminals, and two normally open (NO) terminals. This configuration means it can switch two separate circuits simultaneously, or it can reverse the polarity of a single circuit. The versatility of the 5 blade relay wiring diagram makes it invaluable for complex electrical tasks.
The typical operation involves energizing a coil within the relay. When the coil is not energized, the common terminal is connected to the normally closed (NC) terminals. When the coil is energized by applying voltage to its control terminals (usually pins 85 and 86), an internal magnetic field is created. This magnetic field pulls an armature, causing the common terminal to disconnect from the NC terminals and connect to the normally open (NO) terminals (usually pins 30 and 87 in some conventions, though labeling can vary).
Here are some common applications and considerations for using a 5 blade relay wiring diagram:
- Automotive lighting: Controlling high-power headlights or fog lights without overloading the original switch.
- Accessory control: Powering high-draw accessories like winches, auxiliary fuel pumps, or cooling fans.
- Polarity reversal: In some specialized applications, it can be used to reverse the direction of a DC motor.
When interpreting a 5 blade relay wiring diagram, pay close attention to the terminal numbering. While there are common conventions, always verify the labeling on the relay itself or consult the manufacturer's datasheet. Common terminal designations include:
| Terminal | Function |
|---|---|
| 85 and 86 | Coil energizing terminals |
| 30 | Common terminal (input or output) |
| 87 | Normally Open (NO) terminal |
| 87a (or similar) | Normally Closed (NC) terminal |
Take the time to carefully study the 5 blade relay wiring diagram provided in the following section. This will ensure you have a clear understanding of how to safely and effectively integrate the relay into your project.