# What does C mean on a relay?

## What does C mean on a relay?

Normally closed
English translation: Change-over, Normally open, Normally closed.

What is contact arrangement in relay?

Contact. (1) Contact arrangement. Denotes the contact switching combinations available on a relay and are defined in terms of number of poles, number of throws (single or double), normal position (open or close), and the sequence to make and break.

### What is Form C contact?

Form C contacts (“change over” or “transfer” contacts) are composed of a normally closed contact pair and a normally open contact pair that are operated by the same device; there is a common electrical connection between a contact of each pair that results in only three connection terminals.

What is Form C switch?

Form C (Changeover – break before make) Form C describes a relay with two contact positions, the normally closed contact and the contact which becomes closed when the relay is energised. For a single relay this would also be known as a changeover switch, or a single pole double throw (SPDT).

## What does form C mean?

Changeover – break
Form C (Changeover – break before make) Form C describes a relay with two contact positions, the normally closed contact and the contact which becomes closed when the relay is energised. If the relay has two contacts sets it would be described as 2 Form C contacts, or double pole double throw (DPDT).

How do Form C contacts work?

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What is a Form C contact?

Form C describes a relay with two contact positions, the normally closed contact and the contact which becomes closed when the relay is energised. If the relay has two contacts sets it would be described as 2 Form C contacts, or double pole double throw (DPDT).

## What is a co contact?

Change-over (CO), or double-throw (DT), contacts control two circuits: one normally-open contact and one normally-closed contact with a common terminal. It is also called a Form C contact or “transfer” contact (“break before make”).