Schneider Electric India Website×
DIN protection is active when the circuit breaker is totally closed.
The circuit breaker is able to operate under a short circuit current higher than Icw, but must operate very quickly.
Internal instantaneous protection DIN intervenes in this case, and will inhibit all other settings like Isd, or tripping time delay.
DINF protection is active during closing operation of the circuit breaker.
DINF protection is a self circuit breaker protection intended to trip the circuit breaker instantaneously in case of closing under short circuit. ( lever upper than DINF threshold ). The immediate opening of the contact due to this DINF protection , will avoid the circuit breaker to establish the whole default current, and will decrease drastically the electrodynamics forces in the circuit breaker.