why do all the grounds have to be under 1 wire nut?

Old 04-25-05, 03:17 AM
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why do all the grounds have to be under 1 wire nut?

Just curious. Why can't you group them into two sets and make sure each set is connected to the metal box? Why can't you ground the outlet/switch separately by connecting it directly to the metal box?

Last edited by pascal; 04-25-05 at 03:18 AM. Reason: bad speller
Old 04-25-05, 03:29 AM
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The grounds do not have to all be connected with the same wire nut. However, they all, have to be connected. You can use a pigtail to connect two groups of ground wires if you want.

What is important is that each device be grounded and that the box be grounded, and that all ground wires connect.

Do not put more than one ground wire under a screw on either a device or the box. Do not rely on the box to carry the ground. If the switches and/or receptacles are self grounding, be wary of those connections.
Old 04-25-05, 03:37 AM
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Thanks for the quick reply.

Why can't I rely on the metal box to connect the ground? It is metal.... I won't do this, but i just want to understand why.
Old 04-25-05, 06:04 AM
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If you have a continuous metallic conduit system that is connected from the metal breaker panel enclosure all the way to the metal recep or switch box with no breaks or non-metallic connectors along the way, then the conduit system and metal box is permitted to be your ground. However, I personally do not like to rely on this system in case something may get knocked into the conduit somewhere and separate a joint so that the ground is interrupted. Often you are unaware until there is a problem. But the NEC allows this.

Old 04-25-05, 07:30 AM
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I think rac is refering to the box as the contact ground to the device if the device is grounded type connection. What he is saying is always make up the ground from the device to the ground screw on the box to ensure the device is actually grounded....I have also seen plenty of self grounding recepts go bad and no longer become grounded......better to be safe than sorry and ground it directly to the box with the pigtail versus allowing to rely on the connection from the device ( self grounding ) to the box.......sure code allows it but I think he was talking more from experience.

Also devices to work loose over time with pulling cords out of them and so on..so they can become loose...thus breaking the bond or possibly causing it to break on the self grounding devices....

Last edited by ElectricalMan; 04-25-05 at 07:32 AM. Reason: needed to add a sniglet...lol

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