UPB - does it use a white neutral wire for sending signals, or does it need a third wire?

jokah

Member
I am still confused on this. At first, i assumed it used a neutral wire to send pulses to it.

So lets say a single pole light switch that would normally have the wiring routed like this:

White: Neutral Bus Bar -> Switched (spliced together) -> Light fixture
Black: Breaker -> Switch LINE -> Switch Load -> Fixture.

Would be changed to something like this:

White: Neutral Bus bar -> UPB Controller -> Switch -> Fixture
Black: Breaker ->UPB COntroller -> Switch ->Fixture.



Meaning that the white is now being used in the switch level. Each switch is looking for a specific signal or pulse to be sent across the neutral line. In the cases where a switch isnt a upb controller, the white would simply be spliced as usual?


Now where the confusion that I have is when I look at UPB switches. There is a Hot, Neutral, then Transmitter wire. For instance, it almost seems like theres supposed to be some 18 guage wire fed to each switch to act as a signal. Which means I need to retrofit my 4 year old house?


Does anyone have a good article for me to read, or video, etc?
 
Hi,

A UPB switch should have a least 4 wires. A black wire, which is the "hot" lead and supplies power to both the switch and (via the switch) the load. The white wire is the "neutral" lead and provides the return power path for the UPB switch and the load. The bare or green wire, which is the "ground" lead and is there for safety, and doesn't normally enter into power for the switch or the load. The 4th wire may be brown (at least the brand that I have uses brown) and provides the controlled power to the load (the power to the load comes via the black lead, through the UPB switch, and out to the load).

There may be additional wires which are used to connect UPB "remote" switches. This type of switch doesn't carry power to the load, but simply signals the "main" UPB switch to turn on/off/etc.

The pulses which control the UPB switch from a UPB computer interface, or another UPB switch or UPB controller are carried on the "hot" lead, at least you can think of it that way.

While it is simplification you can think of the power as flowing from the power company, down the "hot" lead to the switch, through the switch, out of the switch on to the load and then returning to the source of the power (the power company) via the "neutral" lead.

That help?
 
Visual aid for Frederick's excellent description (image omits the green grounding wire for clarity).

Virtually all Power-Line Carrier (PLC) switches (UPB, Insteon, X10) need to have their onboard electronics powered at all times and must be connected to the Hot and Neutral lines. Otherwise, they wouldn't be able to listen for incoming signals.
 

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oh oh, i see, so the extra wire i am confusing is merely the LOAD


Where normal switches use black, its just brown for clarity on which is line and which is load.
 
How are home inspectors btw on this type of technology?

I had same concern in a new house I recently built. Electrical inspector made 2 inspections that I know of. First was to check wiring while walls were open with no switches installed. No problem at that point. Next inspection came after everything was closed up including the switch face plates. My electricians told me that there should not be a problem as long as everything worked correctly. As a result, I made sure every switch was properly programed as soon as the electricial had them installed and applied power for me. When inspector came, we explained that we installed smart switches. Inspector said everything should be OK as long as certified electricians installed them and all lights worked as intended. Passed OK. He seemed more concerned that the appliances were wired correctly and that every room had a light controlled by a switch than the technology involved. I think his second inspection was primarily a "ready for occupancy" inspection.
 
oh crap, so you guys run wire, then hoko things up?

I thought we had to have everything hooked up before we put up drywall, etc.

Doh!
 
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