Hey all,
maybe a stupid question: i have no neutral wire in my switches (old house).
But sometimes i have a 2nd circuit running through the wiring box behind the switch.
Can i use any neutral wire running though the house for smart switch/relais because they only need the permanent power to run zigbee/wifi?
Best Mike
Yes, but verify that it really is neutral.
NO, Do not do that. You wouldn’t want to overload that neutral wire with other loads from a different circuit. That load is not meant for other circuits. Not to mention other safety related issue.
I did connect to a neutral wire which turned out to be from a different breaker (outlet next to switch). Seems to work fine for the last 8 years or so
Yes. It will work but it doesn’t pass code and isn’t safe. You could potentially have more amperage on the neutral than the wire is rated for since it is now the neutral wire for 2 circuits.
I the pure sense, I agree.
Consider that a typical IoT device uses maybe 5W which is less than 50mA on a 15A circuit (120V). If there is a sensitive device on the circuit, it is possible that this could cause a problem. Most houses don’t have devices that sensitive.
That said, having a cavalier attitude about about adding devices here and there will eventually come around to bite you. Therefore, be judicious about adding paraisitic devices in this manner and be prepared to face the consequences (worst case scenario: the device causes a fire that burns down the house and the insurance company won’t pay because of the non-code conforming device.)
-OSD
…so better stay “save” and buy Shelly or SonOff “no neutral” relais. THX
It’s a code violation not because of the load the device may draw under normal circumstances. There are a number of failure modes, on either circuit, which this could make worse. And of if either circuit ever gets switched to a GFCI breaker or upstream outlet, this will fail immediately.
If the neutral is from the same circuit, then it would be safe. To pass any future inspection I would just extend the circuit with the neutral even if the line wire is capped and taped off. A solo neutral wire might confuse the inspector.
You mentioned “overloading”.
Any installation that is not done by certified electrician with certified devices violates the code.
I am in the US and in my state, homeowners are allowed to complete electrical installation on their own home without being a licensed electrician. The work is inspected and approved by the local government’s inspector thus being perfectly legal.
Cool.
They must be busy with smart home installations…
