Use of Shelly 1PM plus to control water heater

Forums › Gadgets, robotics, home automation, electronics (including wearables) › Use of Shelly 1PM plus to control water heater

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timmmay

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#3346743 25-Feb-2025 18:53

SirHumphreyAppleby:

I expect a modern contactor is going to very reliable and see me out. Even the cheapest of cheap relays I've purchased from China will take significant amounts of abuse. I've not killed one yet, even with their coils powered up inside a hot greenhouse and cycling on/off several times each day for years in the early morning/evening trying to maintain 27-30C.

The equivalent part without the switch is the 5TT5800-0, $40.51.

Thanks, that's very useful :) For bonus points... would you know the name of a switchboard din rail mounted switch that could completely bypass the Shelly / contactor? I can't find one on the RS website because I don't really know what they're called. I tried "DIN switch" and a few variations with no luck.

Is wiring a Shelly and a contractor to a switchboard considered an easy job for an electrician who'd be installing a solar system? I'm guessing yes, but I wonder if I need to give them any guidance.

SirHumphreyAppleby

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#3346745 25-Feb-2025 18:57

timmmay:

Thanks, that's very useful :) For bonus points... would you know the name of a switchboard din rail mounted switch that could completely bypass the Shelly / contactor? I can't find one on the RS website because I don't really know what they're called. I tried "DIN switch" and a few variations with no luck.

I expect you could use a SPDT or DPDT switch. I'd search for those terms apply filters to limit the results to DIN mounted units.

timmmay

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#3346747 25-Feb-2025 19:02

SirHumphreyAppleby:

I expect you could use a SPDT or DPDT switch. I'd search for those terms apply filters to limit the results to DIN mounted units.

Thanks, no luck there. Maybe I'll just ask the electrician to source one 🙂

Spyware

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#3346754 25-Feb-2025 19:34

Schneider Electric R9S06291 is a switch disconnect, 2P, 100A.

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timmmay

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#3347755 25-Feb-2025 20:48

Spyware:

Schneider Electric R9S06291 is a switch disconnect, 2P, 100A.

Thanks, I appreciate that. I can't find it on RSOnline and I'd rather buy there to reduce shipping fees, so I'll keep searching. The best I can find is this one but the current is a bit low. Looking for single pole to reduce space in the switchboard. If anyone knows how to find stuff on the RS website that'd be appreciated :)

SirHumphreyAppleby

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#3347763 25-Feb-2025 21:36

timmmay:

Thanks, I appreciate that. I can't find it on RSOnline and I'd rather buy there to reduce shipping fees, so I'll keep searching. The best I can find is this one but the current is a bit low. Looking for single pole to reduce space in the switchboard. If anyone knows how to find stuff on the RS website that'd be appreciated :)

I was looking for a way to switch between a direct feed and a common Shelly-controlled feed, but a simple switch will also work (and is easier/cheaper to find). Selecting source I/II is more logical to me than having a switch marked 'off' for something that may actually be on and receiving power form another source. The switched contactor takes any guess work out of it so that's the route I will use myself.

SomeoneSomewhere

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#3347766 25-Feb-2025 21:46

Contactors fail pretty frequently - usually under motor loads, though.

'Several times a day' is pretty low duty for many contactors/applications. You normally talk in terms of many starts per hour before needing to go solid-state. Industrial contactors generally have separately replaceable contacts because they absolutely wear out.

With a resistive load at half rating and no other heat-producing devices, you'll probably get pretty good life.

With switches, you can just use a breaker. 'SPDT' and 'DPDT' don't normally get used for high power stuff; you're looking for a single pole isolating switch like this.

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timmmay

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#3347770 25-Feb-2025 22:05

Thanks for that. Out of stock until May! I can find others now though thanks. A basic switch can be more expensive than you'd expect

I think a separate switch is more likely to survive if the contactor fails, but I might get the contactor with the switch just because it sounds easier.

petearr

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#3351014 7-Mar-2025 14:27

If it helps,

Shelly now have a "powered by Shelly" Ogemray Smart relay 25A (6000w).
Which sounds like a drop in replacement for their Shelly 1PM and would be perfect for this.

Hopefully an importer is able to get a SDoC sorted for it.

timmmay

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#3351017 7-Mar-2025 14:37

petearr:

If it helps,

Shelly now have a "powered by Shelly" Ogemray Smart relay 25A (6000w).
Which sounds like a drop in replacement for their Shelly 1PM and would be perfect for this.

Hopefully an importer is able to get a SDoC sorted for it.

That will be perfect for a hot water cylinder control, once it's available in AU / NZ and has the SDOC. The price is very good too. I have Shelly EM PRO Wi-Fi Energy Meter on the way from smarthome AU.

Has anyone ordered from smarthome recently? Did you get an email notification of your order? I didn't get emails about ordering or shipping, and the tracking number on their website for my order was wrong. I emailed them and they sent me the proper tracking number. Their website has a few odd problems.

SpookyAwol

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#3351304 8-Mar-2025 10:44

petearr:

If it helps,

Shelly now have a "powered by Shelly" Ogemray Smart relay 25A (6000w).
Which sounds like a drop in replacement for their Shelly 1PM and would be perfect for this.

Hopefully an importer is able to get a SDoC sorted for it.

Looks like a good option, but for a HWC and my use case, I still have to have a temp add on too.

SirHumphreyAppleby

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#3351305 8-Mar-2025 11:01

petearr:

Hopefully an importer is able to get a SDoC sorted for it.

I wouldn't assume third-party manufacturer will pay for AU/NZ certification like Shelly does with their own products.

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