Electric apparatus for electric wiring installations, namely, switches, deviators, communicators, electric plugs and sockets, cartridges type fuses, fuse holders, electric bells in general, electric bells for two or more tones, circuit breakers, isolators, namely, electronic current loop isolators, optical isolators, signal isolators, low and medium power switches, solid state switches, electric panel circuit boards for working sites, distribution circuit boards, command and control circuit boards, whether combinable or not, control desks, combinable control desks, ganged terminal blocks, derivation boxes with terminals, combinable terminal circuit boards, computer fly terminals,emergency warning lamps, phase test apparatus, apparatus for measuring electric magnitudes, security fuse bearers with plugs and sockets, electronic apparatus mountable as common electric wiring devices, namely photo-electric relays, thermostats, electric sunset switches, level signalers, pressure signalers and electric limit switches, simple and bi-stable relays, timers and timer switches, dimmers, earth leakage circuit breakers, thermal magnetic and earth leakage circuit breakers, small ganged circuit breakers which may be inserted in wiring device supports, small electric transformers, remote control switches, relay panels or circuit boards, principal and auxiliary post and shunts for voice transmissions, electric door speakers, telephones, loud speakers, television door speakers, video telephones, closed circuit television sets for civil and industrial use, electric microswitches, electric limit switches, automatic electro safety valves, combustible gas detectors, poison gas detectors, smoke detectors, movement detectors, panel circuit boards and sirens