Normally Open Auxiliary Contact Symbol

Auxilliary contacts symbols for use in electrical pneumatic and hydraulic schematic diagrams.

Normally open auxiliary contact symbol.

Available in svg png. These are contacts of relays contactors timers counter field instrument switches pressure switches limit switches etc. A form c would have 3 leads and would have 1 normally open and 1 normally closed circuit. Auxiliary contact 1nc 1no.

In other words when voltage is applied to the relay contactor terminals this contact closes. A limiting condition is wired through the coil contacts and resulting conditions are wired through the. These terminals are usually labelled as normally open common and normally closed no c nc. Each symbol means a single terminal itself.

This is also called a changeover device because the common contact changes from the normally closed position to the normally open position when the coil is energized in a relay or a magnetic field is nearby in a reed switch. Iec 60617 sample drawing. No terminal nc terminal and com terminal represent contact terminals symbols. It consists of a coil and a number of auxiliary normally open or normally closed contacts.

These have two states on or off. There are two basic auxiliary contact types. 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. These are known as normally closed n c and normally open n o 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 n c contacts are for example used as electrical interlocks where two contactors are used for forward reverse operation. Those that are closed in the non activated state or those that are open. There is a common electrical connection between a contact of each pair that results in only three connection terminals.

When voltage is applied this contact opens and interrupts current. Normally open no contacts allow current when the relay or contactor is energized. Normally open terminal normally closed terminal and common terminal respectively. Normally closed nc contacts allow current through when the relay or contactor is not energized.

On the other hand contact point a contact point b and contact point c represent contact structures. Output coil can be auxiliary contactor or main contactor coil. We can tell this switch is a normally open no switch because it is drawn in an open position. There are two types of contacts no normally open and nc normally closed.