FIELD: electrical engineering.
SUBSTANCE: proposed device designed for controlling three-phase load, for instance three-phase motor, incorporating protective and warning gear has three-phase optoelectronic relay for controlling thee-phase motor and pilot light unit. In addition, device is provided with phase distortion protective gear that has optron with light-emitting diode and making contact connected in parallel with light emitter of three-phase optoelectronic relay. Phase failure in three-phase mains (or voltage drop across phase below admissible level) drives optron light-emitting diode whose making contact shorts out light emitter of three-phase optoelectronic relay, the latter turns off and de-energizes three-phase motor.
EFFECT: enlarged functional capabilities due to affording protection of three-phase load against phase distortion in three-phase supply mains.
1 cl, 1 dwg
