Form C Relay Wiring Diagram

Form C relay is a device that’s known for its ability to switch between two separate circuits. To put it simply, it’s like a switch that has two separate switches built within it. In this article, we will discuss the wiring diagram for Form C relay in an easy to understand language.

What is a Form C relay?

A Form C relay, also known as a changeover relay, double-pole double-throw (DPDT) relay, or transfer relay, is an electromechanical device that can switch between two separate circuits. It’s referred to as “Form C” because the contacts of the relay are arranged in a C-shaped configuration.

This relay is commonly used in applications where it’s necessary to switch between two circuits, such as in a control system where two different sources of power are used. The Form C relay is versatile and reliable, making it a preferred choice in many industries.

The Wiring Diagram for Form C Relay

The wiring diagram for Form C relay is straightforward, and it consists of four pins or terminals. These terminals are labeled as NO (Normally Open), NC (Normally Closed), C (Common), and Coil. The following is a brief explanation of each terminal:

Terminal Pin Number Explanation
NO 1 Normally open contact
NC 3 Normally closed contact
C 2 Common contact
Coil 4 Coil connection

The wiring diagram indicates that the NO and NC contacts are in series with each other, and they can switch between the common contact (C). When the relay coil is not energized, the NC contact is closed, and the NO contact is open. When the relay coil is energized, the NO contact closes, and the NC contact opens.

FAQs about Form C Relay Wiring Diagram

Q: How do I wire a Form C relay?

A: To wire a Form C relay, you need to connect the NO and NC contacts to the relevant circuits. The common contact should be connected to the load, and the coil connection should be connected to the control voltage source.

Q: What is the difference between a Form A and Form C relay?

A: Form A relay, also known as a normally open relay, has only one set of contacts that are normally open. In contrast, Form C relay has one set of normally open contacts and one set of normally closed contacts.

Q: Can I use a Form C relay in a low-voltage control circuit?

A: Yes, a Form C relay can be used in a low-voltage control circuit. However, the relay coil must be connected to a voltage source that’s compatible with the relay’s specifications.

Q: What is the purpose of the relay coil?

A: The relay coil is responsible for energizing the relay’s contacts, enabling them to switch between the circuits. Without the coil, the relay’s contacts would remain in their default state.

Q: How do I know if my Form C relay is working?

A: To test if a Form C relay is working, you can use a multimeter to check the continuity of the contacts when the coil is energized or de-energized. You can also check the voltage across the coil to ensure it’s within the relay’s specifications.

Conclusion

Form C relay is an essential device that is widely used in various industries. Understanding the wiring diagram for Form C relay is crucial in ensuring proper installation and operation. By following the guidelines provided in this article, you’ll be able to wire a Form C relay with ease.