In assenza d'alimentazione; i rele si diseccitano automaticamente (condizione di sicurezza positiva), in questo caso gli apparecchi collegati ai rele, se alimentati autonomamente, vengono attivati.
On power failure; the relays de-energize automatically (safe condition positive), in this case the devices connected to the relay, if self-powered, are activated.
In absence of power supply; the relay is de-energize automatically (a condition of positive safety), in this case appliances connected to the relay, if fed independently, are activated.