Connecting NC/NO relays
Introduction
Applicable for appliances: VT825 & VT825DC with VT18 / extension module, VT825i, VT825ii, VT855i, VT855ii, VT960i, VT960ii,
These systems can connect up to x2 loads managed by built-in relays. Built-in relays have independent separate entrances and exits. The appliances use latching relays, when the power on the appliance switches on/off, relays remain in the command position!
Purpose
Relays are needed for control of AC/DC mains: e.g. lamps, fans, or other devices.
The maximum possible output current of the relay is 10A.
The maximum voltage for DC current is 9-30V.
Function
A relay is an electromagnetic switch operated by a relatively small current that can control a much larger current.
The relay has 5 pins, x3 of them are high voltage terminals (NC, COM, and NO) that connect to the device you want to control.
The mains electricity enters the relay at the common (COM) terminal. While the use of NC & NO terminals depends upon whether you want to turn the device ON or OFF.
Example 1: When current flows through the coil, the electromagnet becomes charged and moves the internal contacts of the switch. Normally open (NO) terminal connects to the common (COM), and the normally closed (NC) terminal becomes disconnected.
Example 2: When the current stops flowing through the coil, the internal contact returns to its initial state i.e. the normally closed (NC) terminal connects to the common (COM), and the normally open (NO) terminal reopens.
COM (Common): This is the pin you should connect to the signal (mains electricity in our case) you are planning to switch.
NC (Normally Closed): A normally closed configuration is used when you want to turn off the relay by default. In this configuration, the relay is always closed and remains closed until you send a signal from the Vutlan monitoring system to the relay module to open the circuit.
NO (Normally Open): A normally open configuration works the other way in which the relay is always open until you send a signal from the Vutlan monitoring system to the relay module to close the circuit.
Connecting the load using relays
The maximum possible output current of the relay is 10A.
The maximum voltage for DC current is 9-30V.
Do not insert the terminal plug into the relay terminal socket RLY1 ... RLY2 while the external voltage source is turned on.
Example 1: Controlling AC 230V light
Example 2: Controlling DC 12V, 1A lock