3 way switches

[Jpflex]

I believe it’s a newer 2020 code to be required to run a neutral with each light switch box for future electronic devices but must neutrals be connected at box or can you just have wire available?

Also I have yellow and blue going to traveler terminals and black to one line and other black screw from second switch to load power

Does all look ok?

 

[Tulsa Electrician]

Looks like you have some of the conductors insulation under the screw.

Are those switches rated for standard conductors?

 

[HEYDOG]

I believe it’s a newer 2020 code to be required to run a neutral with each light switch box for future electronic devices but must neutrals be connected at box or can you just have wire available?

Also I have yellow and blue going to traveler terminals and black to one line and other black screw from second switch to load power

Does all look ok?

If conductors are installed in a raceway and the grounded conductor is not needed for the switches being installed….you don’t even have to install it. Because it is in a raceway you can pull it in if it is later needed as long as the raceway is large enough! 404.2(c)(1).

 

[Jpflex]

Looks like you have some of the conductors insulation under the screw.

Are those switches rated for standard conductors?

I don’t like using stranded but that’s all we had for ground wire

Also I was not aware devices had to be listed for stranded

Wire insulation is not under screws

 

[Little Bill]

Aside from the neutral not required if a raceway is used, you don't have to run it to both switches in a 3-way if the lighted area is visible from both switch locations.

 

[Tulsa Electrician]

I don’t like using stranded but that’s all we had for ground wire

Also I was not aware devices had to be listed for stranded

Wire insulation is not under screws

Nothing wrong with using stranded.

It's not really that big of deal. I would bet most are rated for stranded.

Thanks for letting me know on the insulation.

Thanks for sharing pictures, keep up the good work.

 

[winnie]

I don’t like using stranded but that’s all we had for ground wire

Also I was not aware devices had to be listed for stranded

My understanding is that standard screw terminals are listed for both solid and normal stranded wire. (But this is from memory, so take with a grain of salt.)

There is a trick for using stranded wire on screw terminals. After you strip the wire, twist it in the 'backward' direction before forming the hook and placing on the screw. When you tighten the screw it will tend to _tighten_ the twists of the wire and snug the hook into the terminal, rather than loosening the twists and making sort of a bird's nest.

Another trick is to strip the wire in such a way as to leave a bit of insulation right on the tip of the wire, forming a little ring that holds the strands together.

-Jon

 

[augie47]

I believe it’s a newer 2020 code to be required to run a neutral with each light switch box for future electronic devices but must neutrals be connected at box or can you just have wire available?

Just FYI, the requirement for the grounded conductor was introduced in the 2011 Code I believe. and revised somewhat in subsequent Codes (2020 had no changes). The requirements vary depending on the applicable Code so you need to check 404.2. As noted, in your particular situation with a conduit system the conductor can be added later if fill requirements allow,

 

[Joethemechanic]

I hate running neutrals places where I don't need a neutral. Suppose my whole lighting circuit is 240v and I don't even have a neutral?

 

[augie47]

I hate running neutrals places where I don't need a neutral. Suppose my whole lighting circuit is 240v and I don't even have a neutral?

If it's a dwelling unit it's likely to be a violation of 210.6

 

[winnie]

I hate running neutrals places where I don't need a neutral. Suppose my whole lighting circuit is 240v and I don't even have a neutral?

This is one of those 'but you might need it later' codes. Not sure that I agree with the code or its intent, but the issue is that lots of 'smart light controls' require a neutral, and code is saying that if you install a light switch you have to be able to upgrade it to a 'smart light control'.

-Jon

 

[Rick 0920]

This is one of those 'but you might need it later' codes. Not sure that I agree with the code or its intent, but the issue is that lots of 'smart light controls' require a neutral, and code is saying that if you install a light switch you have to be able to upgrade it to a 'smart light control'.

-Jon

I happen to agree with it Jon. I've done service work in a lot of older homes where the owner or an electrician has replaced the switch with a smart lighting controller that required a neutral. If a neutral wasn't present, they went to the light and disconnected the EGC and tied it into the grounded conductors to give them a neutral at the switch. Now you have a bare wire that is carrying current. Not a good idea!

 

[hillbilly1]

I happen to agree with it Jon. I've done service work in a lot of older homes where the owner or an electrician has replaced the switch with a smart lighting controller that required a neutral. If a neutral wasn't present, they went to the light and disconnected the EGC and tied it into the grounded conductors to give them a neutral at the switch. Now you have a bare wire that is carrying current. Not a good idea!

They went to more trouble than the ones do around here! Most just tie the neutral to the ground. The ones I have gotten lately have a white sleeve, and a green sleeve. If you tie to the neutral, you use the white sleeve, if you tie to the ground, you use the green sleeve. This is in accordance to the installation instructions.

 

[winnie]

If you tie to the neutral, you use the white sleeve, if you tie to the ground, you use the green sleeve. This is in accordance to the installation instructions.

This comes from a bit of sketchy history.

The UL standard for switches permits a certain amount of leakage, because no insulation system is perfect.

As insulation systems improved, unintentional leakage went down. Some manufacturers started _intentionally_ allowing current to flow to ground to provide the necessary control power for the device (the dimmer, timer, whatever). So you had devices which _intentionally_ used the EGC as a current carrying conductor, but for an extremely small current in the range of what the UL previously permitted as unintentional leakage.

I have mixed feelings about this. On the one hand: intentionally using the EGC to carry current - yuck. On the other hand, it seems quite the waste to require an full neutral for the possibility of _microamps_ of current to power an electronic control.

-Jon

 

[hillbilly1]

This comes from a bit of sketchy history.

The UL standard for switches permits a certain amount of leakage, because no insulation system is perfect.

As insulation systems improved, unintentional leakage went down. Some manufacturers started _intentionally_ allowing current to flow to ground to provide the necessary control power for the device (the dimmer, timer, whatever). So you had devices which _intentionally_ used the EGC as a current carrying conductor, but for an extremely small current in the range of what the UL previously permitted as unintentional leakage.

I have mixed feelings about this. On the one hand: intentionally using the EGC to carry current - yuck. On the other hand, it seems quite the waste to require an full neutral for the possibility of _microamps_ of current to power an electronic control.

-Jon

And then too, if you have enough of them on a circuit that is gfci, nuisance trips could result. (Gfi is still doing what it was designed to though)

 

[gar]

230608-1434 EDT

I do not understand what most of you have been saying.

Don't use the words hot, neutral, and .EGC.

A 3-way circuit consists of a power source, a wire from the power source to a first switch, next two wires to a second switch, a single wire to the load, and a return wire to the power source.

The important point is that this circuit needs the return path for any conductor to have in close proximity a conductor that carries the same current in return to provide a counteracting magnetic field to the forward current's field.

...

 

[Rick 0920]

230608-1434 EDT

I do not understand what most of you have been saying.

Don't use the words hot, neutral, and .EGC.

A 3-way circuit consists of a power source, a wire from the power source to a first switch, next two wires to a second switch, a single wire to the load, and a return wire to the power source.

The important point is that this circuit needs the return path for any conductor to have in close proximity a conductor that carries the same current in return to provide a counteracting magnetic field to the forward current's field.

...

I don't think the OP referenced this as a 3 way. This could be a single pole application where a neutral (grounded conductor) is not present at the switch.

 

[winnie]

230608-1434 EDT

I do not understand what most of you have been saying.

The important point is that this circuit needs the return path for any conductor to have in close proximity a conductor that carries the same current in return to provide a counteracting magnetic field to the forward current's field.

A traditional 'switch loop' consists of an ungrounded conductor, the 'switched' ungrounded conductor, and nothing else. Any current flowing on the ungrounded conductor to the switch will return in close proximity on the controlled ungrounded conductor. We ignore the rest of the circuit and are just discussing the 'switch loop'.

Code changed, and an EGC was required along with all circuit conductors. So that a 'switch loop' would have two circuit conductors (ungrounded and 'switched' ungrounded) along with the EGC.

A 'three way' switch loop is similar, having an ungrounded conductor and two switched ungrounded conductors.

A switch isn't a load, but is placed in series with the load. It isn't necessary to run a grounded conductor to the switch, because balanced current flows in the ungrounded and switched ungrounded conductors.

Technology advanced, and _switches_ which themselves consumed power entered the picture. This includes various time switches and dimmers. Some of these devices are powered by being placed in series with the load. But some require a small amount of control power continuously, and this _control power_ is electrically in parallel with the load.

Providing this continuous control power without a grounded conductor at the switch location is the problem.

Often this control power is provided by intentionally using the EGC as the grounded circuit conductor. The code change 'requiring the neutral at switch locations' is to provide for future modification to use switches which require control power.

-Jon

 

[gar]

230608-1635 EDT

The title of this thread is 3-way switches, then also look at post #5.

..

 

[GoldDigger]

.....
Another trick is to strip the wire in such a way as to leave a bit of insulation right on the tip of the wire, forming a little ring that holds the strands together.

-Jon

Another way to do this is to leave extra length in the bare wire after the point where you start to strip it, then leaving the cut insulation entirely on the extra length of wire, not just a small ring. Once the wire has been wound around and been held by the screw you can cut off the excess wire with the cut off insulation still attached.