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Author Topic: Knob & Tube and circuit breaking switches  (Read 5939 times)

Offline animalhouse

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Knob & Tube and circuit breaking switches
« on: February 03, 2014, 06:50:19 pm »
After much frustration, I am seeking help with figuring out how to wire a few light fixtures for z-wave.

Problem #1: Fluorescent tube-style kitchen lights with 3-way switch on knob & tube. Due to ballasts, dimmer is not an option. Wiring schematic  below based on hours of troubleshooting with a multimeter. Either switch breaks the circuit and the power is run first through the light, then onto the switches.

Problem #2: Power source runs first through light fixture, then to switch, so when switch is off, circuit is broken, meaning no power is running to the switch. Would prefer to continue using my CFL's in these fixtures, but I know putting them on dimmers would kill them much faster. Some are on knob and tube and some aren't.

Questions:
1. Are there any z-wave devices are out there which are knob & tube (2 wire) compatible?
2. Given the fixture - switch circuit interruption wiring, are there any options other than dimmers?
3. Is there a way to solve either problem without rewiring the knob and tube to be romex?

Problem 1 wiring is similar to photo.

Problem 2 wiring is similar to this: http://www.buildmyowncabin.com/electrical/power-into-light-wiring.gif

Offline BulldogLowell

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Re: Knob & Tube and circuit breaking switches
« Reply #1 on: February 03, 2014, 07:06:30 pm »
yeah, you have no neutral wires in your switches which is quite common. 

That will be a problem... except you can try the aeon appliance switch it will allow for you to wire up nicely.

Look at the attached and try "three way switching with Live Wire"

I'm adding more attachments for the benefit of the forum.

http://www.amazon.com/Aeon-Labs-Aeotec-In-Wall-Appliance/dp/B008VWAPU4/ref=sr_1_1?ie=UTF8&qid=1391472697&sr=8-1&keywords=aeon+appliance+switch
« Last Edit: February 03, 2014, 07:12:08 pm by Bulldoglowell »

Offline BulldogLowell

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Re: Knob & Tube and circuit breaking switches
« Reply #2 on: February 03, 2014, 07:07:57 pm »
as promised

Offline BulldogLowell

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Re: Knob & Tube and circuit breaking switches
« Reply #3 on: February 03, 2014, 07:10:21 pm »
last one

Offline animalhouse

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Re: Knob & Tube and circuit breaking switches
« Reply #4 on: February 03, 2014, 08:46:34 pm »
Awesome, thanks! I actually have an aeon appliance switch here!

I only have two wires coming out of the outlet that lead to the fixture, and neither are neutral, so what do I do given that info?

There are two knob and tube wires that come to the outlet, then the 3-wire romex between the two switches.

Offline RichardTSchaefer

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Re: Knob & Tube and circuit breaking switches
« Reply #5 on: February 03, 2014, 09:00:38 pm »
Make sure you kill ALL power in the house if you are working in a crawl space.
A friend of my dad never came out of the attic alive ... He apparently contacted some Knop and Tube wires not related to what he was working on.

There are likely to be live wires even for circuits you are not working on ...
Be VERY careful.


Offline BulldogLowell

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Re: Knob & Tube and circuit breaking switches
« Reply #6 on: February 03, 2014, 09:30:00 pm »
Awesome, thanks! I actually have an aeon appliance switch here!

I only have two wires coming out of the outlet that lead to the fixture, and neither are neutral, so what do I do given that info?

There are two knob and tube wires that come to the outlet, then the 3-wire romex between the two switches.

Knob and Tube (All Alternating Current) has a Hot line and a Neutral, even if it has no ground.  Usa a Voltage Meter to determine which is the Hot wire and which is the Neutral.  The hot wire should show 120Volts when compared to a Ground, like a metal pipe or a nearby grounded outlet.  Remember, whilst the Neutral line won't register a voltage when compared to a ground, it is still very live and you should (to Richard's point) exercise great care, turn off the breaker to the circuit you are working first, then the main.

Separate the two wires coming into the light fixture and mark them as the Line (hot with black tape and neutral with white tape) and load (ones going to the light).  The other wires go to your switches and you will need to check and double check after you disconnect the power to the light that there is no power at either switch (before and after you turn off the power).  I have personally made assumptions on three way wiring and learned about 120Volts quickly.


Offline jpuser

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Re: Knob & Tube and circuit breaking switches
« Reply #7 on: February 05, 2014, 07:33:25 pm »
I understand and appreciate all the wiring diagrams for the Aeon Micro Switch. However, from a practical standpoint, how do you connect all the wires to the Aeon switch when they are not in the same box... e.g., Legs from two different 3 way switches to the "switch" ports on the Aeon switch, Or the "line" legs from both the load (light fixture) and the Line (circuit box) in a 3 way circuit.

I have two cables in my switch box for my 3 way circuit. One cable has a black and white (not sure if it is Line or Load, haven't tested yet), the other cable is Black, Red (two travelers) and White (Neutral).

Can anyone provide advice on how to connect the Aeon Micro Switch given this scenario?

Thanks