Normally Open Relay Wiring

When the relay turns on the common move from nc to no.

Normally open relay wiring.

The no normally open spst single pole single throw relay has an opened circuit state when no current is applied to its coil so basically it disconnects the power to the load in the inactive state. Relays and contactors have two types of contacts each suited for different applications. 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.

So when wiring up these relays the coil wire s will connect to pins 2 7 on the socket. See my switch terminology page for more on contact arrangements if you need to. When connecting to the plc the plc input acts as the load. Mechanical relays create a clicking sound that indicates movement o the common terminal.

Normally open no contacts allow current when the relay or contactor is energized. Pin s 8 6 as normally open pin s 8 5 as normally closed. The other pole has. 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.

Most alarms with this feature will not provi. If the contact is broken with the relay at rest then the relay is referred to as normally open no and if. The no normally open connection of the relay is not connected until the relay turns on. When current is applied to its coil the generated magnetic field switches the armature and closes the contact so you can say that it turned on the load fan light bulb etc.

The following is a wiring diagram of an open collector pnp sensor. Pin s 1 3 as normally open pin s 1 4 as normally closed. Starter kill normally open. You will notice that the load appears between the 0v blue and switching wire black.

In other words when voltage is applied to the relay contactor terminals this contact closes. This normally open starter kill relay application below relies on a ground from the alarm when disarmed and 12 volts from the ignition to enable the driver to start the vehicle. The iso mini relay we have looked at above has 4 pins or terminals on the body and is referred to as a make break relay because there is one high current circuit and a contact that is either open or closed depending upon whether the relay is at rest or energised. The 0v blue will be attached to the common input and the switching wire black will be attached to the input number.