What's a differential switch?
A differential switch (also known as a loss current switch or earth leakage switch) is a personal protection and no product protection. The device protects you and your housemates against electric shocks on contact with (usually metal) devices that have a loss current. The current then flows through the body through the body to earth.
A differential switch is an automatically operating switch that de-energises an electrical installation as soon as a loss current exceeds a certain value, the most frequently used values are 30mA and 300mA.
A differential switch is placed at the start of the installation (main differential switch 300 mA) or circuit (additional differential switch for humid rooms 30 mA).
Both loss current switches are mandatory in the installation to obtain a statutory inspection.
How does it work?
A differential switch measures the current that the installation absorbs (L1) and the amount of current that flows back (N). Both must be the same size.
If the amount of electricity entering the electrical installation is greater than the current that flows back, then we speak of a loss current. This is a current that flows through the ground. The loss current switch will detect this and switch off the entire installation.
- The switch-off time of a differential switch must not exceed 0, 2 seconds.
- In addition to the on / off button, there must also be a test button to check the correct operation of the differential switch.