3 way switch-I think I did something wrong-One switch always has to be "On".

[Snoonyb]

And again I ask, "which of the 4, reading the presents of voltage, would be the primary, and which, reading the presents of voltage, be the switch leg, and in which combination of switch positions?"

Because, the sketch in post #11, assumes the, "PRIOR KNOWLEDGE OF", which isn't the case here.

 

[Eddie_T]

We could help if we saw the truth table. What's going on now is less than productive.

 

[Snoonyb]

You're the advocate, so step up.

 

[Eddie_T]

Step up to what, where's the info to work with?

 

[Snoonyb]

OP's #1.

Instruct him, describe the step by step process.

 

[Eddie_T]

Truth table.

 

[Snoonyb]

So, you don't know.

 

[Eddie_T]

I'm guessing you don't understand the truth table concept.

 

[Snoonyb]

See post #25, if you can.

 

[Eddie_T]

See post #25, if you can.

A truth table is merely a table revealing all switch positions and indicating presence or absence of voltage on each terminal for each switch position.. I can't make it any simpler than that.

 

[Snoonyb]

And erroneously assumes the, "PRIOR KNOWLEDGE OF", which isn't the case here.

And does not identify the primary power source, or the switch leg.

Interestingly, you've yet to, in specific detail, describe the process, and the numerous switch positions involved and how you would determine the primary power conductor, or the switch leg, based upon the information included in the OP's #1 post.

After all, you say it's so simple, so, step up.

 

[PJB12]

I didn't find any suggestion that one of the new switches is defective. It happens sometimes. Home Center devices are a common place to get defective wiring devices.

If you're not comfortable and knowledgeable about electrical safety practices, it may be wise to call an electrician. This diagnosis takes a very short time for an electrician, so your invoice will be far under one hour.


If you are comfortable and follow all safety practices and make all connections in a fire safe way, try this Step-By-Step method

What we will do first is to try to identify the Line In conductor that carries voltage from the circuit to the switch-

Turn the circuit off & either lock it off or tape the panel door closed with a note on it.
Remove both switches. A Critical Step for Diagnosis
Disconnect all wires and separate them so no bare ends can touch.
Unscrew the light bulb(s) A Critical Step for Diagnosis
Put small alligator clips on the probe tips of your meter & set it to Volts A/C
Clip one lead to the ground coming into the switch box or the box if it is known to be grounded well.
Clip one lead to any other wire in the box.
Turn the breaker on.
Is there 120 volts (+/-) showing on the meter?
. YES- This is the "Line In" conductor. It goes on the black color screw on the new switch.
. The other cable in the box contains the travelers & usually the neutral (but not always)
. NO- This is a neutral or a traveler.

Turn the breaker off
Move the alligator clip to another wire.
Turn the breaker on
Is there 120 volts (+/-) showing on the meter?
YES- This is the "Line In" conductor. It goes on the black color screw on the new switch.
The other two are the travelers
NO- This is a neutral or a traveler.

Repeat until you find Line In.
This wire goes under the dark colored screw on the switch.

There should be another cable in that box with two or three conductors. If two, those are the travelers. They go to the other box. If three, the while one is probably Neutral. (See below for how to confirm)

Step Two Is To Identify The Neutral:
Breaker Off
Switches Removed
Light Bulb Removed
Meter on "Ohms"
Clip one lead to a known good ground
Tap each other wire until you get Zero Ohms (or close)
That is the Neutral. It does not connect to either switch.

Next We Will Identify The Conductor Going To The Light Fixture:
Do this after you have identified the Line In and the Travelers, above

If it is on, turn the breaker back off
Screw a known good incandescent light bulb back in. (Optionally- Use a screw base fuse instead of the bulb)
Clip a meter lead on a ground
Set the meter on Ohms
Tap the other meter lead on each wire in the box
The one that shows Zero Ohms (or close) is the neutral for the light bulb.
The other wire under that cable's sheath is the Line Out to the bulb.
Put that wire on the dark screw on the switch.


Now It Is Time To Confirm Which Are Travelers:
With power off and bulbs removed, tie which two you think are travelers together under a connector.
Go to the other box with your meter set on Ohms.
Clip a lead to a wire.
Tap the other wires.
When you find two that give Zero Ohms (or close) between them, those are the travelers.


If this makes no sense, stare at the drawing I inserted earlier. It should help.

Enjoy Today!
Paul

 

[afjes_2016]

One of the switches always has to be in the "on" position for anything to work

Hang on. Just to be sure here please vyacheslav, if the face of the switches actually say "On" and "Off" then you have the incorrect switches to use in this setup. 3 way switches do not have "On" and "Off" imprinted on them. If you are just referring to the "On" position and you are sure you have 3way switches then fine.

Take a picture of the new switches and post here please for us to see that you have the proper switches.

 

[Eddie_T]

And erroneously assumes the, "PRIOR KNOWLEDGE OF", which isn't the case here.

And does not identify the primary power source, or the switch leg.

Interestingly, you've yet to, in specific detail, describe the process, and the numerous switch positions involved and how you would determine the primary power conductor, or the switch leg, based upon the information included in the OP's #1 post.

After all, you say it's so simple, so, step up.

I made it simple by explaining the truth table. You seemingly have a mental block that veils your understanding. PJB12 is essentially describing a truth table in longhand. The truth table permits one to revisit the logic as many times as necessary w/o repeating steps. It's a boolean expression oft used by engineers and technicians but in reality just a quite simple notation of facts in a table format for all to see.

 

[Eddie_T]

I'll mention another possibility which a truth table might bring to light. In the past there were other legal methods to wire 3-way switches and even switches that differ (California switch, Chicago switch) and alternate wiring methods that placed the lamp between common terminals. I have never used them but the terminals on a California switch may not be a direct terminal-to-terminal match to current 3-way switches. It might be wise to map the double throw paths before tossing an old switch. I wired to use the least amount of wire for all switches and my garage 3-way especially was wired to use the least amount of three conductor wire and may not meet current code.

 

[Snoonyb]

I made it simple by explaining the truth table. You seemingly have a mental block that veils your understanding. PJB12 is essentially describing a truth table in longhand. The truth table permits one to revisit the logic as many times as necessary w/o repeating steps. It's a boolean expression oft used by engineers and technicians but in reality just a quite simple notation of facts in a table format for all to see.

You've explained nothing, just referenced it, so how about a step b y step in all the combinations of switch positions, that I've repeatedly ask for?

 

[Eddie_T]

You've explained nothing, just referenced it, so how about a step b y step in all the combinations of switch positions, that I've repeatedly ask for?

Only the OP can supply that data.

 

[Snoonyb]

I didn't find any suggestion that one of the new switches is defective. It happens sometimes. Home Center devices are a common place to get defective wiring devices.

If you're not comfortable and knowledgeable about electrical safety practices, it may be wise to call an electrician. This diagnosis takes a very short time for an electrician, so your invoice will be far under one hour.


If you are comfortable and follow all safety practices and make all connections in a fire safe way, try this Step-By-Step method

What we will do first is to try to identify the Line In conductor that carries voltage from the circuit to the switch-

Turn the circuit off & either lock it off or tape the panel door closed with a note on it.
Remove both switches. A Critical Step for Diagnosis
Disconnect all wires and separate them so no bare ends can touch.
Unscrew the light bulb(s) A Critical Step for Diagnosis
Put small alligator clips on the probe tips of your meter & set it to Volts A/C
Clip one lead to the ground coming into the switch box or the box if it is known to be grounded well.
Clip one lead to any other wire in the box.
Turn the breaker on.
Is there 120 volts (+/-) showing on the meter?
. YES- This is the "Line In" conductor. It goes on the black color screw on the new switch.
. The other cable in the box contains the travelers & usually the neutral (but not always)
. NO- This is a neutral or a traveler.

Turn the breaker off
Move the alligator clip to another wire.
Turn the breaker on
Is there 120 volts (+/-) showing on the meter?
YES- This is the "Line In" conductor. It goes on the black color screw on the new switch.
The other two are the travelers
NO- This is a neutral or a traveler.

Repeat until you find Line In.
This wire goes under the dark colored screw on the switch.

There should be another cable in that box with two or three conductors. If two, those are the travelers. They go to the other box. If three, the while one is probably Neutral. (See below for how to confirm)

Step Two Is To Identify The Neutral:
Breaker Off
Switches Removed
Light Bulb Removed
Meter on "Ohms"
Clip one lead to a known good ground
Tap each other wire until you get Zero Ohms (or close)
That is the Neutral. It does not connect to either switch.

Next We Will Identify The Conductor Going To The Light Fixture:
Do this after you have identified the Line In and the Travelers, above

If it is on, turn the breaker back off
Screw a known good incandescent light bulb back in. (Optionally- Use a screw base fuse instead of the bulb)
Clip a meter lead on a ground
Set the meter on Ohms
Tap the other meter lead on each wire in the box
The one that shows Zero Ohms (or close) is the neutral for the light bulb.
The other wire under that cable's sheath is the Line Out to the bulb.
Put that wire on the dark screw on the switch.


Now It Is Time To Confirm Which Are Travelers:
With power off and bulbs removed, tie which two you think are travelers together under a connector.
Go to the other box with your meter set on Ohms.
Clip a lead to a wire.
Tap the other wires.
When you find two that give Zero Ohms (or close) between them, those are the travelers.


If this makes no sense, stare at the drawing I inserted earlier. It should help.

Enjoy Today!
Paul

The drawing you posted, assumes prior knowledge of both the primary power as well as the load, which is not the case detailed in the OP'S #1.

There are only 3 conductors in each box, as detailed in the thread, so the likelihood of a distinct hot pair, is, to say the least, remote.

 

[Snoonyb]

Only the OP can supply that data.

But, all along you've been stating that it would only take minutes, if they just followed the drawing, so detail those easy specific steps, for all the combinations of switch positions.

 

[Eddie_T]

But, all along you've been stating that it would only take minutes, if they just followed the drawing, so detail those easy specific steps, for all the combinations of switch positions.

Yes.