A disconnector is a device that allows you to separate circuits but does not allow you to switch and protect them. The circuit breaker, on the other hand, can protect, switch, and separate circuits. In other words, the circuit breaker is a safety device that protects the circuit and people through automatic operation, while the disconnector is a switching device that allows a circuit to be opened or closed without an automatic protection function, for example, during maintenance or modification operations within the electrical installation.
What is the difference between a circuit breaker and a disconnector?
Circuit breakers and disconnectors have many differences that will help you compare them and choose which one is most appropriate for your needs. In summary, here are the specific characteristics of each of these two electrical devices:
The function of the circuit breaker is to:
- Protect against overloads and short circuits
- It can be equipped with a differential part to protect against leakage currents
- It cuts power automatically in case of a problem, such as a short circuit or overcurrent
- It can be reset and reused after the power has been cut
The disconnector has the following functions:
- It allows an electrical circuit to be separated from its power supply
- It has no breaking capacity; it cannot cut power in case of a fault
- It must be used when not under load, i.e., when the downstream devices are not operating
- It is used to isolate part of the electrical circuit so work can be carried out safely
How do I choose between a circuit breaker and a switch-disconnector for my electrical installation?
A disconnector isolates a circuit when not under load, enabling the circuit to be shut down and work to be carried out downstream in complete safety. The circuit breaker function allows a live circuit to be opened. It is most commonly found in homes to turn lights on or off (see the Odace Schneider range), but this function is also associated with products such as contactors (see the a9c2..., lc1d, lc1k ranges). Here are the two symbols:
A circuit breaker protects a circuit against overcurrents. These functions provide protection against overloads (thermal) and/or short circuits (magnetic).
The fuse provides protection against overloads and short circuits but cannot be reset immediately.
The isolator function is typically associated with other more comprehensive functions such as the circuit breaker, and the isolator symbol can be found in the electrical symbol of the product: for example, circuit breakers.
The isolator function is also associated with other products, for example:
- The isolator switches iSW, INS, Vario and Mini-Vario range
- Disconnectors with fuse holders (GS, DF, LS1, GK1, STI, SBI range)
- Switch disconnectors in a box for proximity switching
