what are 3 safety devices in circuits?

in circuits there are safety devices usually

i only know 1 of them it is a fuse

does anybody know the other 2?

4 Answers

  • MarkG
    Lv 7
    1 decade ago
    Favorite Answer

    Depends upon what you mean by safety device, circuit protection or operator protection. Operator protection would be devices to prevent a personel from being injured or shocked by hazardous voltages or unsafe conditions.

    Circuit protection devices:

    1,) Fuse

    2.) Circuit Breaker

    3.) PTC Thermistor - limits current by increasing its resistance when heated. Increased current flow generates heat which raises its resistance thereby limiting current.

    4.) Diode for Reverse DC power protection

    5,) Zener Diode - for DC / unipolar over voltage protection

    6.)TVSS - Transient Voltage Surge Suppressor - for DC/AC Bipolar over voltage protection

    7.) Crowbar circuit - see link

    8.) Current regulator

    9.) Thermal shutdown circuit

    10.) Low voltage trip - stops system if low voltage condition is encountered

    11.) Low Voltage Release - same as low voltage trip but will auto restart when correct voltage is applied

    12. Loss of Phase Relay - opens when one or more phases of 3 phase power are lost

    13. Reverse power trip - protects a generator from being motorized

    Operator Safety:

    1.) Polarized AC cord

    2.) GFCI ground fault circuit interrupter

    3.) Isolation Transformer - limits amount of current that can be passed to the circuit, prevents full line current from reaching the circuit or operator

    4.) Emergency Stop - Switches and other devices like light curtains which kill power to a machine when operated. these are placed in locations which are easily located by operators. The machine cannot be restarted by these devices until they are erset and then only the normal start switch will allow a restart

    5.) Electro-motive braking - uses back emf in a motor to hasten the stopping of a motor.

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  • aguila
    Lv 4
    3 years ago

    Safety Devices For Electricity

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  • 1 decade ago

    fuse, diodes, zener diodes? I'm guessing. I know diodes is a second device because it keeps current from flowing in the wrong direction. I want to say Zeners keep the voltage they were built for but I don't know if that is the third answer. Hope you find the third if its not the case.

    Resistors limit current so that may be the third answer.

    And as simple as it may seem, the "switch" may be there.

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  • 1 decade ago

    I think others would be circuit breaker, emergency stop button

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