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I'm concerned with the current wiring of a bedroom light switch box (4 gang, metal box with 4 on/off toggle switches).

Based on the Wiring Diagram included in the post:

  1. I believe the ground wires need to be corrected. Please confirm if there is a problem with the ground wires. How should I correct if needed?
  2. There is a giant wiring nut with 7 wires (6 black, 1 red) loaded into it... is this safe/up to code? What corrective action, if any, should be taken?
  3. I want to remove the two left (shaded blue) switches. How should I do this and maintain electrical connection?

Wiring Diagram

  • The diagram is confusing. A really easy to simplify it for us and answer one of your questions: All green or bare wires are ground wires. They should all be connected together with a wire nut. Plus since it is a metal box, go ahead and add one more green wire and connect it with a screw to the box - like homedepot.com/p/… and then revise the drawing by removing all the ground wires - it will make it a lot easier to read. – manassehkatz-Moving 2 Codidact Dec 30 '19 at 2:11
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    Can you post photos of the insides of this box please? I'm wondering if those switches that "do nothing" are really three-way switches, given that they have white wires connected to them in your diagram... – ThreePhaseEel Dec 30 '19 at 3:06
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You didn't mention what gauge the wires are, so these answers are generic:

  1. Yes, the ground wires should be tied together although there is some debate on whether this is required by code. In this case all the ground wires should be connected together in this box, and the neutrals should all similarly but separately be be connected together (note: don't mix the grounds with the neutrals). Since you will have only two remaining devices in this box, this should be fairly easy. Collect all the ground wires from any Romex that enters the box and bond all of them connector with a wire nut. (See note about wire nuts sizes below.) Do the same for the neutral wires. For grounding, look to NEC sections 250.148 and 250.148(D) Since this is a metal box, make sure there is a "ground pigtail" connected from a ground screw connected directly to the metal box to the ground wires (which you are bonding together in #1 above), as shown in this example.
  2. The color of the wire nut and the specific manufacturer's instructions tells you how many conductors and of what sizes each nut can be used to connect. But generally speaking, 6 or more conductors is not advisable: it's just too easy for one to come loose. If you need to connect more than 5 conductors, I would recommend a "push-in" wire connector, of which there are 2-, 3-, 4-, 6-, and 8-wire variants. Your particular situation should be aided by your question #3 (below) which will reduce the conductor count.
  3. If you have switches which you're sure no longer control anything, just remove the switches and cap the wires with wire nuts. Make sure you've disconneced the hots from the others that are feeding live devices. (Leave the ground connected.) Opinions will vary about whether to keep the neutral bonded to the others. I tend not to.

A few more notes:

  • The Code requires that non-functional switches are removed and replaced with blanks. You should be able to find blank inserts to fit into 2 of the 4 gang slots.
  • Wire nut colors are standardized, but depending on the shape (wings or no wings) and the manufacturer's instructions, some wire nuts hold more than others. I've never seen more than 5 wires successfully in a wire nut that didn't merit replacing. :-)
  • There are rules about how many conductors and devices can fit inside a box. If you post the size of your box (usually marked in cubic inches inside the box) and a new diagram once you've removed the two left-most devices, we can confirm whether your box is filled or over-filled. At first glance, what you've got seems pretty tight (i.e., likely over-filled according to code) with 4 devices. When you remove the 2 switches, that may change.
  • Whether to keep the neutrals separate is a little more complicated. For the above advice, I've assumed all of these switches are fed by one circuit from your panel. If not, let us know and we'll advise how to handle the neutrals.
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    1) The post does mention that the box is metal – ThreePhaseEel Dec 30 '19 at 3:05
  • Good catch @ThreePhaseEel; I fixed my reply to reflect. Thanks. – jbeldock Dec 30 '19 at 3:22
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I wouldn't call the contents of this box a "whole mess". It looks complex but there's nothing really weird in it. Power enters the box via cable 7 and energizes four circuits:

  1. Unswitched power is permanently provided to circuits elsewhere in the house via cable 5. This circuit is slightly strange as both the red and black wires in the 14/3w cable 5 are hot, where ordinarily only one would be used and the other abandoned.
  2. Switches 3 and 4 (as numbered left to right) control the motor and light of a fan on the other end of cable 6.
  3. Three-way switch 1 and a three-way switch on the other end of cable 2 control the load on the other end of cable 3. (You believe this circuit may be disabled.)
  4. Three-way switch 2 and a three-way switch on the other end of cable 1 control the load on the other end of cable 4. (You believe this circuit may be disabled.)

Switches 1 and 2 are both still fully wired. When you toggle a fully wired three-way switch and nothing seems to happen, you have encountered one of several situations:

  • A load is being switched but you haven't found it. Often this is an outlet with nothing plugged in, or a lamp that's locally switched off.
  • A load has been removed.
  • The other three-way switch has been removed and its wires capped off. This will leave the load permanently without power.
  • The other three-way switch has been shorted or replaced by a wire nut, that is, both travelers have been permanently connected to the common. This will leave the load permanently powered on.

You can do some further analysis. Disconnect switch 1, and check which travelers in cable 2 are hot.

  • Neither hot = the other three-way switch has been removed and its wires capped off.
  • Both hot = the other three-way switch has been shorted or replaced by a wire nut.
  • Only one hot = the other three-way switch is still installed.

Do the same for switch 2 and cable 1.

However this doesn't help you very much because if you want to be code compliant you still have to locate the boxes at the other ends of cables 1, 2, 3, and 4 so you can make sure that they are safely and properly decommissioned. Abandoned wires must be separated and individually capped. As jbeldock says in his answer, an abandoned switch must be removed and the space covered with a blank plate.

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