Normally Open Relay Contact

When power is introduced an electromagnet pulls the first circuit into contact with the second thereby closing the circuit and allowing power to flow through.

Normally open relay contact.

The national association of relay manufacturers and its successor the relay and switch industry association define 23 distinct forms of electrical contact found in relays and switches. Time delay relay contacts must be specified not only as either normally open or normally closed but whether the delay operates in the direction of closing or in the direction of opening. As relay diagrams show when a relay contact is normally open no there is an open contact when the relay is not energized. Relays control one electrical circuit by opening and closing contacts in another circuit.

Normally closed nc contacts allow current through when the relay or contactor is not energized. We can tell this switch is a normally open no switch because it is drawn in an open position. Normally open relays default in the open position meaning that when they re not in use there is no contact between the circuits. Form a contacts make contacts are normally open contacts.

The lamp will energize only if someone presses the switch holding its normally open contacts in the closed position normally open switch contacts are sometimes referred to in the electrical industry as form a contacts. The following is a description of the four basic types of time delay relay contacts. In other words when voltage is applied to the relay contactor terminals this contact closes. Of these contact forms the following are particularly common.

Relays and contactors have two types of contacts each suited for different applications. Normally open and normally closed electrical contacts make up electrical switches relays circuit breakers and most any other electrical component that switches something on off or can be switched on off. Relays are switches that open and close circuits electromechanically or electronically.