smart plugs

What do you want to switch them *from*? Remote control, phone app, web browser, home automation system, custom software?

Theo

As I said; I want the immersion to switch on when 240V is seen at the triggering socket. I cannot easily run twin and earth between them. Up till now I have carried the signal via a 12V wallwart and bell wire switching a mains relay with 12V coil. .

If you are running mains over bell wire STOP IMMEDIATELY you run the risk of a fire!

If your immersion has a switch then in theory you can instead run it off a normal socket although a fixed connection point is preferred. You could replace with a Smart socket I use these throughout to control lights and even a small convector heater

Just check that the socket is capable of switching you immersion by checking the current capabilities of the socket match the immersion.

Richard

Personally, I'd feel a lot safer using a contactor. Smart switches/plugs are all very well for lights, TVs and so one. But a heavy load ...

OK so a "Smart Plug" is generally "Smart" and is controlled by an app which may run locally or on a remote server somewhere. This allows voice control, schedules, recording of power usages.

If all you want is on/off you want a dumb plug with a remote control, for example:-

BUT I have my doubts about these. Are they really OK for an immersion heater? Assuming its 3kw I believe regulations say it should be hard wired with a double pole switch, but I couldn't find a suitable equivalent thats hard wired.

Do they really work at 100ft?

Dave

Thanks, as I said I have no knowledge of how smart plugs work, in my case the immersion is only rated at 1.5kW and is switched by a relay currently.

You would probably get way with a smart plug, but a 3Kw immersion definately needs a double pole switch possibly combined with a kosher immersion controller.

Check out the Horstman/Secure E7+ dual rate immersion controller. It has bluetooth and/or Wifi facilities and can be used on tanks with just one immersion heater.

That sounds more like a relay, than a smart switch.

A smart switch would be more for saying "alexa turn the immersion on", or controlling it from your phone, you'd need something with overall house control to see one input turn on, and turn your immersion output on in response ... doable but not with a smart switch alone.

I think I'd worry about fire risk with the internal relay of most smart switches supplying 3kW(?) for a couple of hours ... you can get 20A rated sonoff switches, maybe look at a smartswitch powering a contactor for something beefier?

ie switched from 'software'. Switching based on a mains input wants to be hardware switched - you can stick a layer of software in between but it makes it more fragile, eg doesn't work if there's no internet.

If a push button remote is ok then that could work. I'd suggwst using it to trigger a contactor, but maybe 6A (1.5kW) is ok on the internal relay (often overstated by the Chinese manudacturers)

Doing a voltage detction is more annoying as often these want momentary or toggle inputs on the fob buttons, rather than holding down the button for 'on' and letting go for 'off'. The same goes for wireless light switches. I think you'd need some kind of 'wireless relay' but most that I found on a brief Amazon search involved wifi and apps. I'm sure they must exist.

I suppose you could maybe find a remote 'dawn to dusk' switch and mount it with a lightbulb: light off = immersion on. Would need a relay to invert the input to get the right logic.

Most of these are 433/868MHz RF not wifi, so you can get that kind of range in ideal conditions.

Theo

I find this "won't work without the internet" over emphasised. If there is no internet because there is no power, its doesn't matter. If there is power, then just make sure there is a manual over-ride.

"It Depends" , so yes, those without a hub probably won't work without the internet. Some with a hub will work without the internet. So you can get Draytech Wiser switched plugs which are driven from the Wiser Hub and which work without the internet so long as there is local WiFi. The schedule is stored in the hub. The controlling app connects directly to the Hub so that works without internet but does need WiFi. The plugs connect to the Hub via ZigBee so will work with no WiFi.

Dave

My house system will work without the Internet - it is entirely self contained. The 15A mains relay powered by a PI PICO board will when I get round to it have its own SSID that you can connect anything with wifi cabability to and control it. Although the intention is to use that solely to set it up, after which it would connect to the house wifi.

Yep. That sound like what I am building. No ZigBee tho

On 07/11/2024 17:34, Andrew wrote: > Check out the Horstman/Secure E7+ dual rate immersion controller. > It has bluetooth and/or Wifi facilities and can be used on tanks > with just one immersion heater. Yes but this has more functions than I need. The immersion is already isolated by a normal double pole switch and the mains relay is in a junction box between that and the element [1].

I am a bit surprised that there is no radio controlled switch that can carry a signal over in the same way my piece of bell wire and a 12V wall wart did. I will revert to trying to thread the bell wire up the conduit and under the upstairs floor.

I mean that the OP just wants a relay with a radio link instead of a wire. That could be done in a basic analogue circuit.

When you start dragging in apps and wifi and internet connections and third party platforms and APIs and ... you've just upped the number of failure modes by a lot. Which may not be what you expected from your 'wire'.

eg the Draytek might not need an internet connection, but it's still a big pile of software and if it won't boot today for some reason then your 'wire' doesn't work any more. You never have that problem with wires.

Theo

Until two days ago I would have agreed.

However a 6 hour scheduled downtime from Virgin incapacitated my home Smart network - meaning SWMBO could not work the out of reach switches (which still work manually, to be fair).

Before that - in September - we had a power cut (I posted about it here :) ) which reinforced your POV. No power = no router and no wifi and therefore no smart (or dumb) remote control. Obviously.

Now I am mulling how to improve resilience as cheaply as possible. I may eventually decide that £0 is cheapest and to accept there is a small chance that my smart network may fail.

Unless anyone knows of a cheap failover to mobile data if network connectivity is lost. I do have a Protectli going unused at the moment ...

Perzactly.

When our internet connection in the street broke I was able to plug my mobile phone into my router (a Fritzbox) and use its data connection as my new internet connection.

All my smart devices worked exactly as normal when I did this.

Tim

Yes, I need a 4G -> ethernet backup. Ideally automatic.

I happened to be on TLC and they have some 'wireless HVAC switches':

I find 'mains switch' for £60:

These are all 'industrial' solutions, which are likely to be more robust than a £10 Amazon smart switch which won't be long before it's e-waste.

But if you are able to use a wire it's simpler, cheaper, less power hungry and more reliable, so there's a lot to be said for running one if you can.

Theo

It looks like there's also a wired transmitter for TLC's Quinetic system:

Theo