... prevents unwanted or casual dismounting of connected terminals.Technical Data Pole No:1P,1P+N,2,3P,3P+N,4PRated voltage ... such devices which cause some current surges(groups of bulbs, motors etc.)D The short-circuit release is to be set ... circuits with devices which cause high current surges(transformers,double-pole motors,motors with heavy start etc.)Nominal voltage:1P (single ...