Differential switches

Differential switches are part of the mandatory devices, imposed by the NFC 15-100 standard in each electrical panel, to protect people against all earth faults. Unlike the differential circuit breaker, it does not protect equipment, does not detect overloads or short circuits. But then, how to choose them without making a mistake, One-Elec guides you and explains what you need to remember.

What is a differential switch?

Located between the general circuit breaker (connection) and the branch circuit breakers in the electrical panel, the differential switch constantly monitors the current flowing through the electrical installation and checks that the incoming current is the same as the outgoing current. If it detects a difference, of 30 mA, 300 mA or 500 mA for example, then it means that there is a current leak. This missing current therefore circulates outside the electrical wires, generally a metal carcass of equipment such as a washing machine or a refrigerator. The differential switch will then play its role of protecting people and de-energizing the electrical circuit to avoid potential electrocution.

What is the difference between a differential switch and a differential circuit breaker?

The differential switch and the differential circuit breaker are both protective devices against electrical risks. But the differential switch ONLY protects people. The differential circuit breaker protects people AND property (equipment, circuit, electrical installation).

• Differential switch = personal protection
• RCD = protection of people AND property.