Is the switch grounded when I screw it onto a grounded metal box?
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An electrician can give you this answer. Is the box properly grounded? A negative ground attached to ungrounded box is still ungrounded. I consulted an electrician and he told me it was always better to ground the device on the device and not the box. Also, our city code wants all boxes to be plastic and not metal.
Was this Answer Helpful ?Possibly but it is not always a solid ground even if the metal conduit runs all the way to the breaker box. if you have a meter you can test between the box and the neutral. It is always best to attach a third wire ground if you have one.
Was this Answer Helpful ?there is a ground screw on the switch opposite side of the two hot (brass) screws. Usually house supply wiring has a bare wire to attach to ground screw (sometimes painted green). Attaching a switch ground to the metal box doesn't necessarily ground the fixture unless the metal box is already grounded.
Was this Answer Helpful ?Yes, if the metal box is grounded properly, the metal yoke and fastening screw will also be grounded when in contact with one another and securely fastened.
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