Relays are electronic switches that can be used to control various electrical circuits. One of the most popular types of relays is the 4 pin micro relay. In this article, we will discuss the wiring diagram for a 4 pin micro relay and how it can be used in different applications.
What is a 4 pin micro relay?
A 4 pin micro relay is a small-sized relay that has four pins. It is a type of electromagnetic relay that is commonly used in automotive applications. Micro relays are smaller in size than standard relays, making them ideal for use in compact spaces. They operate by an electromagnetic field that creates a magnetic force that moves a contact arm, allowing or blocking the flow of current.
Pin Configuration
The four pins of a 4 pin micro relay are labeled as 85, 86, 87, and 30. The pins are arranged in a square-shaped pattern, with pins 85 and 86 positioned on the top row and pins 87 and 30 positioned on the bottom row. The pin configuration is illustrated in the table below:
| Pin Number | Pin Label |
|---|---|
| 85 | Coil Negative (-) |
| 86 | Coil Positive (+) |
| 87 | Normally Open (NO) |
| 30 | Common (C) |
Wiring Diagram
The wiring diagram for a 4 pin micro relay is shown in the figure below:
The wiring diagram shows the connection between the four pins of the micro relay and the electrical circuit. Pin 85 and 86 are connected to the coil of the relay, which creates the electromagnetic field. Pins 87 and 30 are connected to the load or the electrical component that needs to be controlled. In the normally open (NO) configuration, when the relay is not energized, there is no connection between pins 30 and 87. When the relay is energized, the connection is established, allowing the flow of current through the load.
Applications of 4 Pin Micro Relay
The 4 pin micro relay is commonly used in automotive and industrial applications for various purposes, such as:
Automotive Applications
The micro relay is used in automotive applications, such as controlling the headlights, fog lights, wipers, and other electrical components. It is also used in the fuel pump control, fan control, and starter relay.
Industrial Applications
The micro relay is used in industrial applications, such as controlling the motors, pumps, and valves. It is used in the automation systems, HVAC systems, and control panels.
FAQ
What is the difference between a 4 pin and a 5 pin relay?
The main difference between a 4 pin and a 5 pin relay is the presence of an additional pin in a 5 pin relay. The extra pin is labeled as 87a and is used for the normally closed (NC) configuration. In a 5 pin relay, there are two configurations, the normally open (NO) and the normally closed (NC), whereas in a 4 pin relay, there is only the normally open (NO) configuration.
Can a 4 pin relay be used as a 5 pin relay?
No, a 4 pin relay cannot be used as a 5 pin relay, as it does not have the additional pin required for the normally closed (NC) configuration. The 5 pin relay can be used as a 4 pin relay, by ignoring the additional pin and using only the four pins required for the normally open (NO) configuration.
What is the maximum current rating of a 4 pin micro relay?
The maximum current rating of a 4 pin micro relay depends on the manufacturer and the model. However, most micro relays have a maximum current rating of 30 amps.
Can a 4 pin micro relay be used in a 12V electrical circuit?
Yes, a 4 pin micro relay can be used in a 12V electrical circuit, as it is designed to operate within the range of 12V to 24V DC.
What is the life expectancy of a 4 pin micro relay?
The life expectancy of a 4 pin micro relay depends on the quality of the relay and the conditions in which it is used. However, most micro relays have a life expectancy of up to 100,000 cycles.
