Smart switch needed - Bought a Deta but no earth!

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Benoire

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#320102 6-Jul-2025 20:39

Howdy folks

Want to get a smart switch for the outdoor cabin so I can turn both internal and external lights on remotely. I bought a 2 button deta smart switch as it would integrate with the Grid Connect system I've already got out there but after trying to fit it today it turns out it doesn't have an earth which is a problem as the lights require an earth and are not double insulated.

I presume it is unwise to run the switch without the earths and therefore I need something different. Disappointed that the Deta lacks an earth terminal but nothing I can do.

Any thoughts?

Cheers

Chris

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#3391377 6-Jul-2025 22:27

I'm lost. Why do you need an earth terminal in a switch? It has no interaction with the switch.

You just connect the earth wires using a separate screw connector to maintain continuity of the earth and carry on.

Benoire

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#3391385 7-Jul-2025 06:26

Handle9:

I'm lost. Why do you need an earth terminal in a switch? It has no interaction with the switch.

You just connect the earth wires using a separate screw connector to maintain continuity of the earth and carry on.

Ok so use a terminal block or some other method of safely terminating the 3 earths together and not worry about it?

Handle9

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#3391386 7-Jul-2025 06:30

Benoire:

Handle9:

I'm lost. Why do you need an earth terminal in a switch? It has no interaction with the switch.

You just connect the earth wires using a separate screw connector to maintain continuity of the earth and carry on.

Ok so use a terminal block or some other method of safely terminating the 3 earths together and not worry about it?

Yeah. All you want is to maintain continuity of the earth conductor.

Benoire

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#3391387 7-Jul-2025 06:44

I presume something like this:

https://www.mitre10.co.nz/shop/hpm-cable-connector-10pk-clear/p/103016?srsltid=AfmBOoo_WAqrWaliFRKkeaV-auEy0T3yNZgLVs1TG-yMzq_p1QVbsfxE

This will allow the cables to be safely connected as the 3 earths are already twisted together.

gregmcc

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#3391419 7-Jul-2025 11:14

Benoire:

Howdy folks

Want to get a smart switch for the outdoor cabin so I can turn both internal and external lights on remotely. I bought a 2 button deta smart switch as it would integrate with the Grid Connect system I've already got out there but after trying to fit it today it turns out it doesn't have an earth which is a problem as the lights require an earth and are not double insulated.

I presume it is unwise to run the switch without the earths and therefore I need something different. Disappointed that the Deta lacks an earth terminal but nothing I can do.

Any thoughts?

Cheers

Chris

Not trying to be mean here, but one of the key requirements of a homeowner been allowed to do (limited) electrical work is that they are competent "having the necessary ability, knowledge, or skill to do something successfully". it obvious to me that they are lacking in the knowledge part of this which also leads me to doubt the skill level.

My suggestion is that you should engage an electrician to help you out as it appears you are attempting something that you are not competent in. The potential here is more than a light not working. When working with electricity a bad outcome can be very serious.

Benoire

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#3391427 7-Jul-2025 11:28

gregmcc:

Benoire:

Howdy folks

Want to get a smart switch for the outdoor cabin so I can turn both internal and external lights on remotely. I bought a 2 button deta smart switch as it would integrate with the Grid Connect system I've already got out there but after trying to fit it today it turns out it doesn't have an earth which is a problem as the lights require an earth and are not double insulated.

I presume it is unwise to run the switch without the earths and therefore I need something different. Disappointed that the Deta lacks an earth terminal but nothing I can do.

Any thoughts?

Cheers

Chris

Not trying to be mean here, but one of the key requirements of a homeowner been allowed to do (limited) electrical work is that they are competent "having the necessary ability, knowledge, or skill to do something successfully". it obvious to me that they are lacking in the knowledge part of this which also leads me to doubt the skill level.

My suggestion is that you should engage an electrician to help you out as it appears you are attempting something that you are not competent in. The potential here is more than a light not working. When working with electricity a bad outcome can be very serious.

I get that, I've just never NOT seen a lighting circuit OR switch not run with an earth - every house I've lived in (I'm english so this is my first NZ house) has been earthed and all light run / switches have had earth slots hence the question about the deta - the current dumb switch has an earth loop which is what I expected and with metal fixtures it concerned me about the switch itself. Its not mean to point these things out - I've got electricians coming back as part of the bathroom reno underway so I can get them to do it.

richms

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#3391432 7-Jul-2025 11:38

If there is no contactable metal on the switch, then it has nothing to earth. Some like the old wemo ones have a metal bracket and ends up with an earth tail from it because it was designed by americans, but no metal = no earth needed. If they were to put a terminal labelled with it there then it has to be connected and that means that people with older wiring with no earth would not be able to install it.

Richard rich.ms

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gregmcc

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#3391435 7-Jul-2025 11:56

It is quite common in older houses pre early 80's where lighting circuits were 2 core only and no earth as they supplied a batten holder light fitting, it was also very common for the live to go to the light fitting and then a 2 core run to a light switch (with no neutral at the switch).

As far as i'm aware there has never been any requirement for an earth to be present at a light switch, there is a current requirement for an earth to be present at each light fitting (needed or not).

Benoire

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#3391438 7-Jul-2025 12:20

gregmcc:

It is quite common in older houses pre early 80's where lighting circuits were 2 core only and no earth as they supplied a batten holder light fitting, it was also very common for the live to go to the light fitting and then a 2 core run to a light switch (with no neutral at the switch).

As far as i'm aware there has never been any requirement for an earth to be present at a light switch, there is a current requirement for an earth to be present at each light fitting (needed or not).

Wow! I'm 45 and never seen such a wiring example!

The house was rewired before we moved in so all lights and sockets are earthed and the fixtures require an earth due to the metal casings. I guess on reflection I just expected the deta switch to have an earth loop as that has always seemed the safest place as it keeps the earth connection protected.

Appreciate the insights, it just wasn't something I expected!

Bung

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#3391696 7-Jul-2025 13:53

gregmcc:

Not trying to be mean here, but one of the key requirements of a homeowner been allowed to do (limited) electrical work is that they are competent "having the necessary ability, knowledge, or skill to do something successfully". it obvious to me that they are lacking in the knowledge part of this which also leads me to doubt the skill level.

My suggestion is that you should engage an electrician

If the electrician is unsure of anything he can ask on another forum without being told to go back to school 😋

richms

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#3391701 7-Jul-2025 14:19

Also for the OP, use the Tuyasmart app, not the deta skinned version incase you add devices from other brands later. They used to add to the deta/arlec app Ok, but recently have been getting a not allowed error when trying to connect them.

Richard rich.ms

larknz

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#3391731 7-Jul-2025 17:28

richms:

If there is no contactable metal on the switch, then it has nothing to earth. Some like the old wemo ones have a metal bracket and ends up with an earth tail from it because it was designed by americans, but no metal = no earth needed. If they were to put a terminal labelled with it there then it has to be connected and that means that people with older wiring with no earth would not be able to install it.

The earth connection in a light switch is just a loop terminal for connecting wires together and has no electrical connection with the switch.

Handle9

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#3391732 7-Jul-2025 17:34

Benoire:

I presume something like this:

https://www.mitre10.co.nz/shop/hpm-cable-connector-10pk-clear/p/103016?srsltid=AfmBOoo_WAqrWaliFRKkeaV-auEy0T3yNZgLVs1TG-yMzq_p1QVbsfxE

This will allow the cables to be safely connected as the 3 earths are already twisted together.

Yup. Sometimes they’ll come in the pack with the switch.

steve2222

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#3391774 7-Jul-2025 21:42

richms:

Also for the OP, use the Tuyasmart app, not the deta skinned version incase you add devices from other brands later. They used to add to the deta/arlec app Ok, but recently have been getting a not allowed error when trying to connect them.

Just as an FYI, I did not have this experience when I just added a generic Tuya based smart garage door controller sourced from AE.

In fact adding it to the Grid Connect app was the easiest/simplest device I have added. With all my Deta/Arlec products I have always had to resort to App Mode to add them.

richms

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#3391777 7-Jul-2025 23:12

Seems that deta was one of the holdouts with the ESP8266 modules in them that lack bluetooth pairing so AP mode was needed in most cases. I have a friend who was well invested in the grid connect app and the last few ali purchases will not add to it, and when he reset a long ago one that was in the grid connect app, it was not wanting to add back in.

Richard rich.ms

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