Wiring question

Want to install several X10 relay switches in the house to turn on lights r= emotely. This would obviate my walking across the room in the dark to get = to the light switch.

Problem: The X10 switch/relay requires full power at the wall switch locat= ion. Several of my switches have only a hot leg coming into the box with n= o neutral. X10 docs. recommend simply running a neutral wire into the box.= =20 Question: Most of my wiring is within the attic and some of the switches a= re on the exterior walls. These locations are inaccessible from the attic = since this is where the roof meets the ceiling ergo providing mere inches o= f crawl space. It would be much easier to run the neutral wire from below = (I have a generous 42" high crawl space). =20 Question: Does this neutral have to come from the same circuit? Can I sim= ply come from any circuit (even a separate new circuit) and run a white neu= tral wire to each switch box? Does it have to be from the same phase? X10= docs. do mention that if not from the same phase, then the phases can be j= oined at the box.

All comments, advice and suggestions appreciated.

Ivan Vegvary

Reply to
Ivan Vegvary
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remotely. This would obviate my walking across the room in the dark to ge= t to the light switch.

ation. Several of my switches have only a hot leg coming into the box with= no neutral. X10 docs. recommend simply running a neutral wire into the bo= x.

are on the exterior walls. These locations are inaccessible from the atti= c since this is where the roof meets the ceiling ergo providing mere inches= of crawl space. It would be much easier to run the neutral wire from belo= w (I have a generous 42" high crawl space).

imply come from any circuit (even a separate new circuit) and run a white n= eutral wire to each switch box? Does it have to be from the same phase? X=

10 docs. do mention that if not from the same phase, then the phases can be= joined at the box.

Andy comments: The neutral (white) wire is not phase sensitive, so it can come from anywhere. However, it will NOT meet code, if that is a concern...

Have you considered the idea of using a table lamp and an X10 module at the wall plug ?

I really sympathize with your plight of trying to add wiring in an exterior wall.... I hope some genius on this newsgroup will post a response showing a simple way to do it, but it is beyond me....

Andy in Eureka, Texas , PE

Reply to
Andy

They make a motion sensor wall switch that works off only the hot leg in the switchbox. You can try that as an alternative.

Reply to
Mikepier

remotely. This would obviate my walking across the room in the dark to get to the light switch.

Several of my switches have only a hot leg coming into the box with no neutral. X10 docs. recommend simply running a neutral wire into the box.

on the exterior walls. These locations are inaccessible from the attic since this is where the roof meets the ceiling ergo providing mere inches of crawl space. It would be much easier to run the neutral wire from below (I have a generous 42" high crawl space).

come from any circuit (even a separate new circuit) and run a white neutral wire to each switch box? Does it have to be from the same phase? X10 docs. do mention that if not from the same phase, then the phases can be joined at the box.

It will work if you connect any neutral, but don't do it and here's why: Suppose you are doing some remodeling or repairs down the road. You kill the breaker to a circuit, check with your meter to make sure the circuit is dead and start unwiring the circuit to replace a bad outlet say. You disconnect the neutral, and all of a sudden it's hot because upstream somewhere you connected your X10 from a different hot circuit to the neutral of the one that you turned off. When you break the neutral, the X10 provides a path to the other hot leg, and the disconnected neutral becomes hot. Yes, it's current limited by the x10 and wouldn't power a toaster say, but there's more than enough current available to make *you* toast.

This exact situation (doorbell xfmr, not x10) happened to me and I got a good shock. It's especially dangerous because you can check the circuit with a meter all you want before you break the neutral, and it won't show that it's hot (because it's not, at that time). This is why I always treat the neutrals as hot until they are disconnected and verified to be dead.

So bite the bullet and do this some other way. And it is against code, if you need another reason.

HTH,

Paul F.

Reply to
Paul Franklin

remotely. This would obviate my walking across the room in the dark to get to the light switch.

location. Several of my switches have only a hot leg coming into the box with no neutral. X10 docs. recommend simply running a neutral wire into the box.

on the exterior walls. These locations are inaccessible from the attic since this is where the roof meets the ceiling ergo providing mere inches of crawl space. It would be much easier to run the neutral wire from below (I have a generous 42" high crawl space).

come from any circuit (even a separate new circuit) and run a white neutral wire to each switch box? Does it have to be from the same phase? X10 docs. do mention that if not from the same phase, then the phases can be joined at the box.

I'm curious as to the wording X10 uses. It is a code violation and potentially dangerous. There is a company that makes a wireless, batteryless, wall switch receiver - transmitter kit. The wall switch looks identical to a Decora switch, and can even be ganged with other switches. The receiver module is small and will fit in most fixture canopies. I've used them, they work great, the only issue is that the set costs around $200. The company is called Enocean

Reply to
RBM

remotely. This would obviate my walking across the room in the dark to get to the light switch.

location. Several of my switches

simply running a neutral

That's a Code violation. *All* conductors are required to be in the same raceway, conduit, or cable.

on the exterior walls.

meets the ceiling ergo

neutral wire from below

Then run an entirely new cable.

Yes.

white neutral wire

No.

the same phase,

That's not a meaningful concept with respect to the neutral.

No disrespect intended, but you should hire an electrician to do this for you. You don't appear to have sufficient knowledge to do this safely.

Reply to
Doug Miller

It's not just a question of whether it meets Code or not. This is also a safety issue. What you propose is dangerous:

The neutral conductor carries the same current as the hot conductor. When two circuits are cross-connected to use the same neutral, the current in the neutral is the *sum* of the currents in the two hot legs. A current of 15 amps in each of two hot legs will result in a 30A current in the neutral. This risks a fire.

Also, someone working on one circuit and not knowing that the neutral carries current from a different circuit could receive a fatal shock from that neutral -- how would he know to shut down both circuits?

Reply to
Doug Miller

ts remotely. =A0This would obviate my walking across the room in the dark t= o get to the light switch.

location. =A0Several of my switches

ecommend simply running a neutral

ches are on the exterior walls.

roof meets the ceiling ergo

the neutral wire from below

n a white neutral wire

not from the same phase,

One possible solution is to use one of the X10 light switches that don't use a neutral. They only work with incandescent bulbs, but since he only mentions controlling lights that would seem to be at least a possibility that would save a hell of a lot of work.

Reply to
trader4

remotely. This would obviate my walking across the room in the dark to get to the light switch.

location. Several of my switches

recommend simply running a neutral

are on the exterior walls.

meets the ceiling ergo

neutral wire from below

white neutral wire

from the same phase,

The basic X-10 wall switch (WS467) does NOT require a neutral in order to function. Its major problem is that it won't work with CFLs. However, if you are concerned about energy consumption, it WILL work with LED bulbs. While LED bulbs are quite expensive, they are a lot cheaper than rewiring and require zero effort. And you'll save the money back since WS467 switches are a lot cheaper than the CFL capable ones that require the neutral. This seems to me to be the simplest, safe way to proceed.

Reply to
Marilyn & Bob

Just checked the X-10 site and see that their new incandescent only wall switches DO require a neutral, however the hot wire only switches that I mentioned (WS467) are still available on Ebay.

Reply to
Marilyn & Bob

The other issue with all things X10 is reliability. Since he's apparently just looking to control some lights across the room the reliability will probably be acceptable. Meaning if once in a while it doesn't respond to a command he can just resend it. But for anyone considering rewiring to support X10, they should know it's not 100% reliable and may not suit the application.

Reply to
trader4

Thanks M & B I will order the WS467 switches through ebay. Incandescent bulbs are fine with me.

Should I choose to upgrade to a system that needs a neutral feed, I will run a full cable (circuit) from the service entrance to the switch box. The many safety concerns and code violations posted above are taken to heart.

Thanks everybody,

Ivan Vegvary

Reply to
Ivan Vegvary

This is my vote.

A warning though, once you start putting in motion switches, you will want them everywhere. I started in the kitchen to keep the girls from using the fridge as a night light (low intensity lighting on a M/D) Then came the bathrooms with the toe kick lights and it continued into the hall. Now when you walk around at light, the lights follow you and you are never looking for a light switch in the dark. These are all low level lighting. Most of it is rope light concealed in cornices, toe kicks etc.

Reply to
gfretwell

Andy comments: I am confused as to how you think someone could receive a shock from the "neutral" wire... It is normally not disconnected in any configuration --- only the black (red) hot lead.... All neutrals are connected together, without interruption or disconnects, in the panel... Except for current carrying capability, they are the same wire....

In Ivan's use, the additional current, if any, carried by the neutral is very very very low --- certainly less than an ampere, and would not screw up anything.... He just wants to put in a simple relay module....

Other than that, you are correct, and it's only necessary to let Ivan know of the risk... Personally, rather than rip out a wall to rewire an outlet, I'd probably do it...

Mikepier's idea of a motion sensor that works on just the hot line sounds good to me, too...

However, if there is room in the fixture for the light (or whatever) I'd just put the module in there, since black/white/copper will be present anyway....

Andy in Eureka, Texas P.E.

Reply to
Andy

Because it carries current. The same current that's in the hot.

It doesn't really matter whether it's disconnected or not. It's carrying current.

Consider two simple circuits, A and B, each supplying no loads other than a single 100W light bulb, each of which is turned on -- but, unbeknowst to you, their neutrals are cross-connected. Well and good. Now suppose you need to replace the fixture on circuit A. Knowing that it's on circuit A, you shut off that breaker, and disconnect the hot lead to the fixture. Now when you go to disconnect the neutral lead, you get a shock, because -- and I think this is the point you are missing -- electricity doesn't "follow the path of least resistance" as many people believe, it follows *all possible paths*, including the one that you've just made with your body by touching that energized lead.

Reply to
Doug Miller

remotely. This would obviate my walking across the room in the dark to get to the light switch.

location. Several of my switches have only a hot leg coming into the box with no neutral. X10 docs. recommend simply running a neutral wire into the box.

on the exterior walls. These locations are inaccessible from the attic since this is where the roof meets the ceiling ergo providing mere inches of crawl space. It would be much easier to run the neutral wire from below (I have a generous 42" high crawl space).

come from any circuit (even a separate new circuit) and run a white neutral wire to each switch box? Does it have to be from the same phase? X10 docs. do mention that if not from the same phase, then the phases can be joined at the box.

Can you say "red herring" or "straw man"?

When you shutt of a breaker you ONLY shut off the "line" - not the neutral.

When you go to replace that theoretical outlet, the neutral is STILL GROUNDED at the panel - so there is NO voltage differential between it and ground. Also, the X10 is not a load, like a bell transformer. It is a voltage controlled device - not current - so it is only "injecting" a couple of milliamps into the neutral - so even IF it was ungrounded at the panel (which would make the circuit totally inoperative) it would be doing good to give you a little tickle - muchless harm you.

Reply to
clare

It is illegal - but in the case he's speeking of, NOT necessarily dangerous. The neutral is only required to activate the x10 switch. It is NOT a load neutral 3 connections on the X10 device' Line in , Line out, and neutral. The neutral is only used by the control circuit - which is a voltage controlled switch - not current controlled (think j-fet vs bipolar transistor) -

Reply to
clare

remotely. This would obviate my walking across the room in the dark to get to the light switch.

location. Several of my switches

recommend simply running a neutral

are on the exterior walls.

roof meets the ceiling ergo

neutral wire from below

white neutral wire

from the same phase,

Or throw a single 7 watt ( or higher)incandescent bulb in the circuit with as many CFLs as you want.

Reply to
clare

Huh?

The reason you don't use the "wrong" neutral is just the subtle effect of poor cancellation of the magnetic field generated by current carrying conductors. If the conductor and it's neutral are close to each other their magnetic fields cancel.

The main time neutrals can produce a dangerous situation is when, somehow, they get dis-connected from the power source (either at the service/breaker panel or in an intermediate junction box.) Any kind of a load will make a white wire (your neutral, HOT, HOT, HOT!

Reply to
John Gilmer

No. As has been explained to you there are two very real problems with using the neutral from another circuit and why it's a serious code violation.

1 - As Doug explained above, when doing a repair, you shut off the breaker to circuit A. If that neutral on that circuit belongs only to it, then you can't get a shock. If on the other hand the neutral is actually connected to circuit B which is still energized and has an active load, then current is flowing in that neutral. Exactly what your chances of getting shocked are will vary depending on how it's wired.

Worst case, consider that the neutral arrives in the wall box you happen to be working on. It comes from the other energized circuit's load, into a wirenut that is pigtailed to the switch. Also connected to the wirenut is the neutral wire going back to the panel. You take off the wire nut. Now you have 120V on the neutral coming from the other circuit in your hand. If you happen to be grounded, you complete the circuit.

Best case is you just tap off another neutral and the neutral just ends where you're using it. Even then as Doug pointed out, current divides depending on resistance. Grab that wire while you're grounded to something and some current will flow through you as you are now an alternate path back to the panel.

2 - Conductors are sized for the circuit they are serving and for the corresponding breaker. By sharing a neutral, you could put not only the current from circuit A through it, but also the current from circuit B, exceeding the safe current for that conductor by 2X or even more.

Which would include the poor guy who turns off breaker A then disconnects the neutral, not knowing that the neutral is actually connected to circuit B.

Reply to
trader4

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