Is it necessary to use an exclusive intercom circuit breaker? We received this question here on the website and it is very common you will answer if you need to have a circuit breaker just for the intercom, in addition to explaining some details about the communication circuits, come on guys!
Circuit breaker: Safety component
We often receive questions about a circuit breaker. We have several articles talking about the types of circuit breakers, circuit breaker curves, the difference between three-pole and two-pole circuit breakers, in addition to showing all the characteristics and where, from now on the article will explain why you should or should not use an exclusive intercom circuit breaker.
The first step in answering this question is to analyze how an intercom installation is performed. If you do not know how to install an intercom, read this step carefully, as this will be critical to understanding the final explanation.
The intercom is a communication device composed of two parts, the intercom, which is the part that is outside the residence, and the handset, which is the part that is inside the residence.
The handset is connected to the mains via a 127V or 220V outlet. Communication cables are used between the handset and the intercom, and in this part of the circuit we have extra low voltage electrical signals, and these extra low voltage signals can suffer electromagnetic interference.
Intercom in NBR 5410
Whenever you have questions about electrical installation, you should consult the standard. And on the topic we are discussing, the standard is very specific in its item 220.127.116.11 which says:
- All circuits must be protected against overload and short circuit, and the component that offers this protection is the circuit breaker.
So we already know that the intercom circuit must be protected by a circuit breaker. Now it is enough to know if this circuit breaker needs to be exclusive for the intercom or not, and that information is in item 18.104.22.168 of the standard that says:
- The electrical circuits of the installation must be separated according to their function.
Therefore, knowing that the intercom is a low-power device, the communication circuits must be separated from the outlet circuits for use in household appliances, as shown in this installation example below
Do you remember when we said that extra low voltage signals can suffer electromagnetic interference? This is precisely why the communication cables between the intercom and the handset cannot be installed together with the power cables.
Intercom circuit breaker
Therefore, the use of a circuit breaker only for the intercom is not necessary, since this same circuit breaker can protect the entire communication circuit, including, for example, the surveillance and alarm system.
And people who only have an intercom in the communication circuit, what to do? Following the same orientation of the standard explained above, if the residence has only the intercom as a communication device, in this case, the circuit breaker must be exclusive for this intercom.
Now that you know you must use the intercom circuit breaker, how about learning the step by step how to install an intercom? In this video from the World of Electrical, you can check out many tips that can help you get more and more customers.