The AFM range AFDD consists of a MCB (Miniature Circuit Breaker
) and a Arc fault detection module in a 1 Pole +N, 2 module DIN rail mounted unit. They combine short circuit, overload and arc fault protection and will switch off in the event of these faults being detected.
The Arc detection unit will recognise serial, parallel and ground arc faults in both radial and ring circuits. (Note serial faults in a ring circuit does not always lead to an arc fault due to power flowing to either side of the fault at the same potential voltage.
These units must be switched off when conducting insulation testing to avoid damage to the AFDD.
The AFDD should be tested every month by pushing the Test button.
Recommended terminal screw torque 2Nm.