Normally the fixtures come with a grounding screw that you attach the grounding wire to. If the box you attaching the fixture to is metal and there is no grounding wire present then the grounded conduit should ground you fixture.
If the fixture doesn't have a ground wire attached or a grounding screw, then it doe not require to be grounded . It likely has insulated parts between the base where it attaches to the box and the lampholder. Simply shunt or cap the incoming ground wire with a wire nut. If you're mounting the fixture to a metal box , then attach the incoming ground wire to the box with a grounding clip or screw in the inside back of the metal box.
The simple answer is, it doesn't. This is not a serious problem, if you ensure that the fixture is wired properly. Make sure the line conductor (black wire) is attached to the terminal at the bottom of the socket, and the neutral is attached to the outer (screw part that holds the bulb) conducting casing. ================== I agree with the above answer in that when there is no grounding conductor provided in the box, the ground wire for the fixture is very often ignored. The fixture will work fine without it. HOWEVER, if there should ever be a fault develop between the hot wire and the metal of the fixture, the metal of the fixture is energized and WILL NOT trip a breaker. This is the purpose of the ground wire. It is a violation of code. And over time with dust, spiders, water, and other foreign objects collecting in the fixture you are more likely to develop a fault. The third wire is for your protection. One of the most common ways faults such as these occur is when trouble-shooting or replacing a fixture. If the circuit is energized, moving the fixture around to check it or replace it can bring the hot wire into contact with the metal of the fixture, which may very well be in your hand.
no because the box its grounded
Connect the ground wire from the light fixture to the ground wire in the ceiling box.
you can ground it to the fixture electrical box.
Piggyback off the box for the existing light. Run a wire from the existing junction box to a new junction box (which is placed wherever you want the new fixture). Then, in the existing box, connect the wire coming from the switch, the wire for the existing fixture, and the wire for the new fixture together using wire nuts. Wire up the new fixture, and presto, you have two fixtures on a switch where there was only one before.
The green wire on the light fixture is a ground wire. If there is no ground wire in the conduit, the green wire should be attached to the metal box with a screw.
Connect the ground wire to the metal box.
The fixture box should have a ground screw on the bottom of the box. Sometimes you have to move other wires out of the way to see it. Just reconnect the fixture ground wire to this screw.
Very often the ground wire in the fixture is ignored, or just connected to the box, if there isn't a conductor to connect to. This, however, is a code violation as any fixture with a ground wire is required to have it properly connected to an equipment grounding conductor back to the panel. This is for YOUR SAFETY. Technically you should rewire the circuit with the proper conductors. It is BAD PRACTICE to connect the ground wire to the neutral or white wire because this could create a hazard of its own.
Grounding a plastic box is a little hard as plastic is a nonconductor.be satisfied with grounding to a ground wire.