Wiring in 2477D into a 3 Way

[shergenr]

As usual, I am confused and throw myself to  the mercy of the forum.  I'm trying to replace my 3 way switches with 2 X 2477d, but am confused by the wiring present in the boxes.The image below represents the wiring prior to replacing the switches.  Box A is a double gang and I had previously installed a microswitch in it to control another fixture and only relate that because that wiring had a definitive neutral.  I'm not certain as to the wiring for the 3 ways that I want to replace.

I gather I need to determine a line and a load but want to confirm my thinking:   I believe the black wire hooked to common in Box A is the load, and the black wire in Box B is the line.  When I disconnect the blacks from the switches and turn power on at the breaker, the black wire in Box B has current, the one in A going to common does not..  How do I determine if I have a "neutral" in each box?

Once determined, then I presume I wire Box B line, neutral and cap load and red, while in Box A i pigtail to line, insteon load to the black wire that was on common, cap the red wire, connect white?  

 

Your help is much appreciated, as always.

 

[simplextech]

3-way with Insteon is not done through physical wiring.

Device 1:  Wire as normal with line/load/neutral

Device 2: Wire with line/neutral as there is no load to wire (don't use the traveler)

Add the devices to the ISY and create a scene where BOTH devices are the controller in the scene.  3-way setup complete.

[Goose66]

So in Box A you just have two Romex wires: 1) the "line" with a black and white wire, and the remote with a black, white, and red wire? If this is indeed the case, then the "line" is run to the fixture, and the Romex in box A is technically the "load". You have have the "missing neutral wire" problem.

In a newer home, you would normally have Romex for the "line" entering box A, and Romex for the "load" entering box A (or box B ) with the 14-3 Romex running between the two boxes. So check Box A again and make sure there isn't another Romex that is actually the "line" coming from the breaker box.

If not, try the 2474DWH. This is RF communication only and can work in cases where there is a missing neutral. But only for incadescent.

Also, if the micro switch in box A has access to a neutral, and you can confirm that the neutral from the line for the microswitch comes from the same breaker panel as the "line" shown in box A (the power to the fixture itself), then you could borrow that neutral for the neutral connection for 2477Ds.  Just make sure you undo this before you sell the house (and have it inspected).

[shergenr]

58 minutes ago, simplextech said:

3-way with Insteon is not done through physical wiring.

Device 1:  Wire as normal with line/load/neutral

Device 2: Wire with line/neutral as there is no load to wire (don't use the traveler)

Add the devices to the ISY and create a scene where BOTH devices are the controller in the scene.  3-way setup complete.

So, I need to tap the bundled line wire in Box A and connect as line to that switch?  Correct?

So the ISY Scene takes the place of cross-linking the switches?  

 

[simplextech]

1 minute ago, shergenr said:

So, I need to tap the bundled line wire in Box A and connect as line to that switch?  Correct?

So the ISY Scene takes the place of cross-linking the switches?  

 

Cross linking or double controller scene is essentially the same thing.  Both devices control the single load.

I may not be understanding your diagram as I'm thinking the devices listed are being replaced?  If so then the device with the load (light) should be wired up normally.  The second device only needs a line and neutral to be active.  It does not need to be the same line as the other device.  Second device just needs power.

[Goose66]

@shergenr If the wiring is as you showed it in the diagram, then DON'T USE THE LINE WIRE FROM ANOTHER CIRCUIT (if that's what you mean by "tapping the bundled line wire." You may create a very dangerous 240V short circuit! Check the wiring in Box A to ensure your diagram is correct. If so, then the "line" for the light circuit comes into the light fixture - not the box. You can borrow a neutral from another circuit (even though it is not to code) because the only current going through it is the power for the switches - not the light. So you won't overload any wiring. 

So the resulting wiring in Box A looks like this:

Black from "line" wire in Box A -> black wire on 2477D and black wire on 14-3 to Box B

White from "line" wire in Box A -> red wire on 2477D

White (Neutral) in other circuit -> white wire on 2477D and white wire on 14-3 to Box B

and in Box B:

Black from 14-3 -> black wire on 2477D

White from 14-3 -> white wire on 2477D

Red wire on 2477D is capped.

Again, this is only if the wiring is exactly like you specified in your diagram. You may want to pull the fixture and check the wiring there just to be sure before wiring this up this way. As always, if you have doubts, get an electrician involved. Of course, he's going to want to run you a neutral to Box A and won't let you borrow the neutral from the other circuit.

 

 

 

[Goose66]

Here is how I am speculating the current circuit works, again, if your diagram is accurate.

 

Breaker Box                     Light Fixture                          Box A                           Box B

Neutral -------W---------- [ Light ] ------W-------[wire nut]-----B------[ Switch Line ]

Hot -----------B----------[wire nut]-------B-----[ Switch Line ]                         |

                                                                                    [ Switch A ] -----W-----[ Switch B ] 

                                                                                     [ Switch B ] -----R-----[ Switch A ]

 

Sorry I don't have the graphic skills to make a better diagram.

[shergenr]

The white wire in the 14-2 cable is hot/line - does that change your wiring schematic?  Your layout above was to connect the White-14-2  to the Red-2447d wire (which is load).   The black wire in the 14-2 was connected to common on the switch so am thinking that it was acting as load.  So the white 14-2 is supplying line to Box B. via black wire on 14-3 cable.  For box b, I need line and neutral to make it work.

Box A is where all the action has to take place:

1) Pigtail into neutral on the other light switch, and connect to 2447D-White and 14-3 White..

2)  Pigtail into 14-2W+14-3B+2477dB

3)  So is load 14-3R or 14-2B?

Or should I punt and put back in the dumb switches?

 

[Goose66]

If the white wire in 14-2 is hot all the way from breaker (to be verified by looking in light fixture box and, preferably, with a voltage tester), then this is what you should wind up with:

Wiring in Box A looks like this:

Black from 14-2 in Box A (load) -> red wire on first 2477D

White from 14-2 in Box A (line) -> black wire on first 2477D and black wire on 14-3 to Box B

White in other circuit (borrowed neutral) -> white wire on first 2477D and white wire on 14-3 to Box B

Red wire from 14-3 (traveler) is capped

Also, to follow standard protocol, wrap a piece of black tape around the white wire from the 14-2 Romex in Box A close to the connection to signify to anyone else messing around in that box that the white wire is hot and not neutral.

 

and in Box B:

Black from 14-3 (line) -> black wire on second 2477D

White from 14-3 (borrowed neutral) -> white wire on second 2477D

Red wire on second 2477D (load) is capped

Red wire from 14-3 (traveler) is capped

 

You can then follow @simplextech instructions to create a scene in the ISY to handle the three-way functionality (or do it directly from the switches based on the included instructions).

 

One other alternative - especially if you are using LED lighting and the loads are 8-10x smaller than the wiring design - is to rewire the light fixture to the white and black wires of the Romex coming from Box A and just cap the line wires coming from the breaker box in the light fixture. Then back in box A use both the black and white wires from the other circuit. This way, it will be to code. But you need to do an analysis of the load and make sure you aren't overloading the other circuit in Box A (likely limited to 1320 watts total - 110V, 15A, 80%).

 

IMPORTANT NOTE FOR FUTURE LOOKERS: Borrowing a neutral (while not to code) is OK here because the current load placed on the borrowed neutral is limited to powering the 2477D switches (very little current). The light fixture still takes the current load on black (hot) and white (neutral) of the original circuit. If it were to be wired in such a way that the light fixture used the borrowed neutral as well, however, this would be bad. This is because the current load of the light fixture and the current load of the other circuit would all be on the borrowed neutral, yet the breaker for the other circuit would only be detecting max current load on the black wire. Thus, the total current in the white wire could exceed rating without the protection of the breaker and burn it up. This is why the code is like it is. You will also see posts for using the ground in these situations. The same rules apply, and you lose the protection of your grounded switch chassies. If it were me, I may wire it this way temporarily, but I would be looking for a better solution long term - probably running a 14-3 from the fixture or the other alternative provided above.

I am not a certified electrician in your state. Use at your own risk.

[shergenr]

That got it - thanks so much for your time and effort in responding to my plea for help.  Your explanations were well thought out and clear.  Over the mid term, my plan is to delete Box A and rewire both fixtures as single poles.  Box A is next to an exterior doorway that we plan to close up and put in a pantry covering that wall.

I guess if I were to effect the change over to single pole in box b (as a short term measure until remodel), then in box a I would need to do the following:

1)  Borrowed neutral to 14-3W 

2) 14-2W to 14-3B  (line)

3) 14-2B to 14-3R   (load)

 

 

[Goose66]

2 hours ago, shergenr said:

That got it - thanks so much for your time and effort in responding to my plea for help.  Your explanations were well thought out and clear.  Over the mid term, my plan is to delete Box A and rewire both fixtures as single poles.  Box A is next to an exterior doorway that we plan to close up and put in a pantry covering that wall.

I guess if I were to effect the change over to single pole in box b (as a short term measure until remodel), then in box a I would need to do the following:

1)  Borrowed neutral to 14-3W 

2) 14-2W to 14-3B  (line)

3) 14-2B to 14-3R   (load)

 

 

That would work.