This for sure.
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All current flows from Hot to Load terminals. Wires to these terminals
must be rated according to the circuit braker and normally are 12 or
14 gage. Neutral terminal on a switches is used only to power on
switch electronics and this jumper wire could be 16 or 18 gage or even
thinner. But very thin wires is very inconvenient to deal with.
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Thanks! I fixed the post.
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I think the neutrals also kick in when an overload occurs. I would not go under rated circuit breaker.
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Thank you everyone who has replied! I wasnāt expecting to receive this much assistance/participation.
Iām new to the smart home world and Iām glad to see the Hubitat community is this friendly and helpful! I really appreciate it.
How?
If you have a short from Load to Neutral this jumper wire will not be affected
by high current. Neutral may get a high current only if internal electronics blows.
Oh shut up.
But seriously, we have a bunch of crazy people who think they have nothing better to do than hang out here and help others. Best part of HE is this forum. Amazingly you'll also see that Hubitat's development team is also very active here. Not just support people, the lead developers and the big boss. It's pretty amazing.
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- I have a roll of 14ga romex wire that I have been cutting chunks off. I mainly need the white and ground but also sometimes have needed new black wires. If you have extra black pieces and need a ground I just strip all the black off to use for grounds as well.
- I have also been using some of the included jumpers (pictured above), can confirm the wires seems to be silver even under the tinning, but it is not flexible enough to be pure Aluminum. It might be some sort of copper alloy stranded wire.
- For most switch circuits you will have a 15 amp breaker, safe to use 14ga wire. If there is a 20amp breaker you should use 12ga. You will notice the difference immediately when you work with the wires in the box. 12ga is a PITA.
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Usually you don't connect a neutral to a switch, but with a smart switch you do. This is because a smart switch in and of itself is an electrical appliance (it uses electricity). It uses very little (under 3 watts). Due to this the neutral wire could be a very thin guage, but I would never wire it this way, I would always wire size it according to the breaker, due to this:
This is not an impossibility, so might as well prevent the fire, if and when it happens.
Granted it would require an extremely odd set of circumstances, not only would the internal electronics need to blow, the would need to blow in a manner where the circuit is now drawing 20 amps or less (the breaker doesn't flip) while simultaneously drawing more current then the wire is rated for. This condition would need to exist for a fairly extended time frame, to heat the wire up enough to cause a problem. Very unlikely yes, impossible no.
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This has happened to me once. With an in-wall relay from Monoprice. Worked fine for months and then failed with a loud bang. The breaker also tripped.
Ideally to prevent such a disaster the internal electronics must be fused.
Some of the good devices have this internal fuse.
Very common during a lightning hit. It can easily back up through switches frying the electronics.
This is incorrect. Just think hot = positive, Neutral= Negative. You need to complete a circuit for a load to work.
Perhaps there is some misinterpretation here? I believe @vitaliy_kh was saying that for a smart switch, the load of powering the switch itself is so low that the neutral at the switch could be finer gauge conductor. As opposed to the neutral at the load controlled by the switch.
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It's possible he meant it that way but 90% of the time the same current from the load is going through the neutral in a circuit with a neutral at the switch.
Only few I know of that won't have load current on the neutral at the switch is when the neutral is at the load ( usually you will end up with no neutral at the switch) or a smart add-on switch.
Well, this example is 100% incorrect and therefore irrelevant because it does not
show how internal electronics is powered (sorry, I am lazy to draw diagrams).
Yes, this is exactly right.
In case of Smart Switch/Dimmer circuitry Neutral is necessary only for powering on
the internal electronics. Switch/Dimmer power consumption is extremely low and
as a result current through Neutral wire from the switch to the Neutral bundle
is very low. BUT THIS IS UNDER NORMAL OPERATION OF THE DEVICE.
In case of internal electronics failure and very depend how this electronics fails
current through this jumper wire could be very high.
Yes, it is better to keep this wire fat enough but 16 and 18 gage wires could
tolerate high pick current for a short time.
Again, incorrect thinking.
100% of the Load Current is flowing through the Neutral wire to complete a circuit
as actually shown on your diagram.
But not through this little jumper wire from Neutral Bundle to the Switch/Dimmer.
Again, this connection power on only internal electronics and has nothing to do
with the Load.
PS.
I am EE with 40+ years of experience.
I saw a lot of smoke and sparks related to failing electronics.
Yes, I know very well what I am talking about.
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True with Lutron switches and switch that come with pigtails. some people use other switches such as GE where they connect load neutral to the terminal and a pigtal from that same terminal to the neutral bundle. Not to mention using a smaller gauge will not go well with code doesn't matter how little current is there unless approved by the manufacturer.
This is incorrect. I switch does not have a neutral connected to it (unless it has some internal electronics it needs to power). I would like to see an example of a switch that has a neutral connection that is not using this neutral connection to power internal electronics, I don't believe one exists.
Some switches that have internal electronics do have a neutral wire connected to them. But this neutral wire carries very little current, compared to the current drawn by the circuit the switch is completing.
Could you provide an example of a switch that has a neutral connection, where that neutral connection would be carrying current anywhere close to the current of the switches circuit, even when that switches circuit is simply powering one lightbulb.
Worth noting that not only does this tend to leave a little more room for laying the bundle of wires back into the box ....BUT
....more importantly, I think the "proper twist" that should be made under wire nuts "before nutting" is frequently untidily done in the process of DIY rewiring. I'll claim my own handful of examples way back. The Wagos, done with full insertion, go a long way to mitigating this.
Any old time licensed electrician's in here may argue against them for reasons of contact surface area and inadequate insertion. But everything comes with instructions for proper use.
EDIT: Not to mention that these Wagos give you more room to stick with the wire gauge in the box already when pigtail-ing.
And on the side topic of AL wiring that still prevails in many homes of a certain generation. If you're opening boxes/outlets that have not been amended you might want to know about these:
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I am not pushing for using smaller gage wire for powering just a switch itself.
Main point is - depend on exact wiring diagram current for the powering switch
itself is extremally low.
Wires have a voltage rating for the isolation and current rating for the conductor.
Everything is OK if voltage and current are within limits with derating percentage
applied.
