Ceiling light - bare copper wire attached to crossbar?

[Cabin_Mama]

I'm replacing a ceiling light fixture and when I removed the old one, I am seeing that the bare copper wire from the ceiling was hooked onto the old fixture's crossbar/bracket, and not to the junction box itself as I expected.

Is this OK to replicate with my new fixture/crossbar? It seems like it accomplishes the same thing, but I found it a little odd.

If it truly needs to be attached to the box, would I attach it to the screw in the second picture, on the left?

Appreciate any thoughts!!

 

[Fitter30]

See the green screw on that cross bar that is the grounding screw could move the wire to it just grounds the fixture.

 

[Sponsor]

 

[Cabin_Mama]

See the green screw on that cross bar that is the grounding screw could move the wire to it just grounds the fixture.

Thanks - but isn't that green screw for the green wire from the fixture only? Or can both wires be attached to one screw?

 

[bigb56]

The grounding wire from the Romex cable goes to a green screw in the box. The box does not come with it, you need to add one. The clamp screw you are asking about is a 8-32 and not allowed to be used for grounding, ground screws in fixture boxed are required to be 10-32 and every metal box manufactured in the last 60 or so years will have a 10-32 hole tapped into it for the grounding screw. The grounding screw is usually green but this is not a code requirement, as long as it is a 10-32 it's compliant.

Typically what we do as electricians is we leave the grounding wire long, wrap it around the grounding screw in the back of the box, then take the small grounding wire from the fixture, wrap it once around the grounding screw on the strap then connect both wires together with a wire nut.

Code requires all your wires to be a minimum of 6" anyway, and at least 3" past the outside of the box, meaning if the box is 4" deep you must leave them at least 7" long. There is no maximum and longer is better when there is ample room, which there will be when the correct boxes are chosen.

Never put 2 wires under a single screw, this is a code violation. You are allowed 2 grounding wires of the same size in a ground bus terminal hole, but never under a screw.

 

[Reach4]

Typically what we do as electricians is we leave the grounding wire long, wrap it around the grounding screw then take the small grounding wire from the fixture, wrap it once around the grounding screw on the strap then connect it to the loose end that we left long on the Romex grounding wire.

How about wire-nutting the incoming ground to grounds for the fan and the box?

The box was not even required to be metal under many codes.

 

[bigb56]

How about wire-nutting the incoming ground to grounds for the fan and the box?

That is fine too, but when there is only a single cable coming into the box it is faster and takes up less room to do it the way I described. Probably doesn't matter to a DIY but when trimming a whole house every minute counts.

The main intent of the code is that the metal box must be grounded directly and this ground cannot be dependent on the fixture or the fixture strap being installed. Your method would comply because the fixture and strap can still be removed while leaving the grounding conductors intact.

Even when using your method, I still leave one of the wires long enough to wrap it around the screw first before putting it into the wirenut with the others.

 

[bigb56]

Reach4's pigtail method with the exception that there is no fixture strap.

 

[bigb56]

The box was not even required to be metal under many codes.

True but it appears to be exposed surface mounted work for which no suitable non-metallic box exists.

 

[Bannerman]

When fastening the grounding wire under the grounding screw, the wire loop is to be wrapped in a clockwise direction.

Wrapping in a clockwise direction, will cause the wire loop to become tighter as the screw is being tightened, thereby assisting to keep the loop secured below the screw head. When wrapped in an anticlockwise direction as shown in the 1st 2 images, the wire will tend to be pushed outward and away from the screw head while the screw is being tightened.

The 1st image also shows 1 knockout missing, thereby leaving a non-compliant opening in the box. There are knockout closure inserts available to remidy the situation.

 

[Cabin_Mama]

The grounding wire from the Romex cable goes to a green screw in the box. The box does not come with it, you need to add one. The clamp screw you are asking about is a 8-32 and not allowed to be used for grounding, ground screws in fixture boxed are required to be 10-32 and every metal box manufactured in the last 60 or so years will have a 10-32 hole tapped into it for the grounding screw. The grounding screw is usually green but this is not a code requirement, as long as it is a 10-32 it's compliant.

Typically what we do as electricians is we leave the grounding wire long, wrap it around the grounding screw in the back of the box, then take the small grounding wire from the fixture, wrap it once around the grounding screw on the strap then connect both wires together with a wire nut.

Code requires all your wires to be a minimum of 6" anyway, and at least 3" past the outside of the box, meaning if the box is 4" deep you must leave them at least 7" long. There is no maximum and longer is better when there is ample room, which there will be when the correct boxes are chosen.

Never put 2 wires under a single screw, this is a code violation. You are allowed 2 grounding wires of the same size in a ground bus terminal hole, but never under a screw.

Thank you for this info!! (And all your other replies as well.) How do I determine which hole in the box is the 10-32 hole?

 

[bigb56]

How do I determine which hole in the box is the 10-32 hole?

It will be the one in the back of the box with threads in it. Sometimes, but not always, it will be on a raised bump. If it is not on a raised bump, you'll want to first drive a drywall screw or a small drill thru it into the wood behind it or else you'll never get the 10-32 screw tight as it protrudes from the back of the box a bit and you'll strip the threads before it gets tight.

 

[Cabin_Mama]

@bigb56 This has been so helpful. I will be adding a grounding screw to the box!