Installing Insteon Switches in old home

[Mustang65]

Not sure where this post should have gone....

I just purchased a ton of Insteon switches both 2477S and 2477D. So, the current switch boxes only have a hot wire and a wire to the ceiling light. The Insteon switches have hot, neutral and ground terminals. The question I have is, will the switch work with only running in a neutral wire without the ground?

Another idea I was tossing around was to drop down a CAT5 cable to each of the outlets and wire them to neutral and ground, which would be a lot easier than (2) 14AWG cables down the wall and try to get them into the electrical box. I was looking for the electrical characteristics of the Insteon switches (current wise) to see if this is feasible, but could not locate the data. I can not believe that the switch electronics and switching circuit portion would be more than a few mW.

Prior to ordering/receiving the switches I was going to run CAT5 cables to each of the switch boxes and run them to a Pi to control the lights. The existing wiring would have been used with 5VDC/110VAC relays Prototype worked perfectly, but I decided to go with an off the shelf Insteon products. Probably a dumb idea.

Any thoughts on this.

Project:

9 - 2477S switches

5 - 2477D switches

[lilyoyo1]

Insteon devices require line voltage so cat5 is out of the question. 

You can use a micromodule in the fixture and then rewire so that the line and neutral then goes to the switch box. Once linked, the insteon switch would control the micro module to turn the lights on. Probably would be cheaper/easier to do it that way.

[oberkc]

Grounds are a safety concern, but absent grounds would not have affect on function of switch (no comment on wisdom of that approach).

Neutrals and grounds have the potential to see the full current of the load.  The neutral connected only to the switch  would see the current drawn by the switch.

[jec6613]

There's a reason that 14/2 Romex is 14 gauge and CAT6 is 24 gauge - current capacity.  Using CAT6 would be a disaster with high voltage A/C wiring - don't do that!

The first problem, your ground, is easy.  The ground is almost 100% already there - the metal box itself provides the ground, and the metal conduit conducts it back to the load center.  No, it's not as good as a dedicated ground wire, but it absolutely meets code even today.  You can either tuck the ground wire neatly in the back of the box, as the screws securing the switch will carry the ground potential, or pick up a bag of grounding screws and there should be a screw hole in the back of the box that you can screw the wire into.

As for neutral, you can either 1) Re-wire the fixture with a micro module, then send neutral+hot to the switch instead of hot+load, setting up the in-wall switch as a remote for the micro module, or 2) you can pull a neutral to the box.  If you're BX wired, you'll need to run 14/2 Romex to bring neutral in, but if you have conduit (most of the Chicago area) you can just run a 14/1 wire down from the fixture in the existing conduit.

There's also option 3) Insteon does make a 2-wire dimmer if neither of the other two options are working out for you.  If the light stays on when the switch is off, install a LUT-MLC dummy load.

[mwester]

Cat-5 and line voltage?  No. No-no-no-no!!     There's  lot of code violations that will earn you a "slap on the wrist", but this one will earn you the infamous "building not fit for occupancy" violation.  Here's one example of why that's such a problem -- I know you're thinking it's a neutral, it doesn't have line-voltage, right -- but it can indeed if the cat-5 ever opens up for any reason -- including a pinched cable, wire fatigue (it's only 24 guage wire, after all!).  Another critically-serious issue is what happens with a simple wire-touch type of short circuit (the kind you might create when messing with the wires and wire nuts in the box).  This should usually trip the breaker - but 24 gauge wire is so thin, you may well find that the cat-5 melted and opened up somewhere... and now you have no neutral, and the full 120VAC line level power on the cat-5 cable.  Don't do it, don't even think about it!

[Mustang65]

Just to clarify.  The circuits between the high voltage load circuit side (ceiling light) of the Insteon and the side of the circuit that supplies the 110 source voltage for the Insteon are isolated from each other. The Triac or low-voltage relay, which ever is used is also isolated from the high voltage side of the Insteon. There is no link between them for the neutral connection to the high voltage section from the schematic I saw a while back. A 1/4 amp fuse would be on the neutral side,to protect the CAT5 cable, but the Insteon would crash before that ever happened. Granted, if the neutral line was needed (load side) for other than the mW load of the Insteon circuitry, there would be a major concern. Since I have about 500' of 14AWG wire, I will be running with that for the neutral wire. I also have about 1K' of CAT5.

[jec6613]

1 hour ago, Mustang65 said:

Just to clarify.  The circuits between the high voltage load circuit side (ceiling light) of the Insteon and the side of the circuit that supplies the 110 source voltage for the Insteon are isolated from each other. The Triac or low-voltage relay, which ever is used is also isolated from the high voltage side of the Insteon. There is no link between them for the neutral connection to the high voltage section from the schematic I saw a while back. A 1/4 amp fuse would be on the neutral side,to protect the CAT5 cable, but the Insteon would crash before that ever happened. Granted, if the neutral line was needed (load side) for other than the mW load of the Insteon circuitry, there would be a major concern. Since I have about 500' of 14AWG wire, I will be running with that for the neutral wire. I also have about 1K' of CAT5.

Just because it would work doesn't mean it's safe long-term.  There's always the possibility of 5-10 years from now a fraying wire sending line voltage (and current) down the CAT5 and dumping out through ground, and you'd have melted or burned CAT5 before your breaker tripped to protect you.  Mixing LV and HV is always a bad idea.

[mwester]

1 hour ago, Mustang65 said:

Just to clarify.  The circuits between the high voltage load circuit side (ceiling light) of the Insteon and the side of the circuit that supplies the 110 source voltage for the Insteon are isolated from each other. The Triac or low-voltage relay, which ever is used is also isolated from the high voltage side of the Insteon. There is no link between them for the neutral connection to the high voltage section from the schematic I saw a while back. A 1/4 amp fuse would be on the neutral side,to protect the CAT5 cable, but the Insteon would crash before that ever happened. Granted, if the neutral line was needed (load side) for other than the mW load of the Insteon circuitry, there would be a major concern. Since I have about 500' of 14AWG wire, I will be running with that for the neutral wire. I also have about 1K' of CAT5.

Its a code violation, and a serious one at that.  You can argue your case to the inspector, or you can argue your case to the fire insurance adjuster, or you can hope you get lucky and nobody catches it ever.   Your choice - but I feel obliged to underscore , if not for your benefit at least for the benefit of others that might find their way to this thread via google, that this is simply unacceptable per any North American code (I've not checked any other codes).  And it's unacceptable for very good reason.