On 2021/09/02 at 5:45 PM, Pietpower said:

Also have a POW2 sonoff running a 3kW element.  Burnt the previous one and learned why they burn.  Fixed my mistakes and the new one is working fine. 

But there are better cheaper equipment now for this purpose.

OK so the second one lasted me a bit more than a year now.

 

 

 

Next up I am trying the improver 20A version.

https://www.robofactory.co.za/smart-switches/497-sonoff-pow-20a-elite-smart-power-meter-switch.html

3 minutes ago, Pietpower said:

OK so the second one lasted me a bit more than a year now.

 

 

 

Next up I am trying the improver 20A version.

https://www.robofactory.co.za/smart-switches/497-sonoff-pow-20a-elite-smart-power-meter-switch.html

I have never run mine with loads over 1kW as we know those connections and relays are too small to my liking. I have used a 230V relay driven from the Sonoff output and then the contacts switching my 3kw geyser and heat pump at the same time. Worked well for years.

A worse problem is when you have a geyser element shorting then it will be bye bye to the Sonoff. Here talking about the 3year old versions. Even the current basic is not for high current.

On 2022/09/22 at 6:00 PM, Scorp007 said:

I have never run mine with loads over 1kW as we know those connections and relays are too small to my liking. I have used a 230V relay driven from the Sonoff output and then the contacts switching my 3kw geyser and heat pump at the same time. Worked well for years.

A worse problem is when you have a geyser element shorting then it will be bye bye to the Sonoff. Here talking about the 3year old versions. Even the current basic is not for high current.

This thread is specific to Sonoff and geysers.

With the POW range of sonoff you can measure power usage of the geyser but it does not work if you use a relay.

With the POW sonoff switches you can set a current limit so if you get a element shorting then it can switch off without damage. 

On the POWR2 the 15A rating seems too close thus hoping the 20A rating of the POWR3 is enough.

39 minutes ago, Pietpower said:

This thread is specific to Sonoff and geysers.

With the POW range of sonoff you can measure power usage of the geyser but it does not work if you use a relay.

With the POW sonoff switches you can set a current limit so if you get a element shorting then it can switch off without damage. 

On the POWR2 the 15A rating seems too close thus hoping the 20A rating of the POWR3 is enough.

I had it the topic was not about power measurement but using a Sonoff 16A rating for a 2kW geyser in a save way. The timer function is the key reason.

Edited September 24, 20223 yr by Scorp007

On 2022/09/22 at 6:00 PM, Scorp007 said:

I have never run mine with loads over 1kW as we know those connections and relays are too small to my liking. I have used a 230V relay driven from the Sonoff output and then the contacts switching my 3kw geyser and heat pump at the same time. Worked well for years.

A worse problem is when you have a geyser element shorting then it will be bye bye to the Sonoff. Here talking about the 3year old versions. Even the current basic is not for high current.

Thanks, i am currently using a 30A relay for my 3kW geyser, the one they actually use in geyserwise, i am now giving serious consideration to downgrade my element to 2kW,  even in order to make it more friendly to my 5kW inverter system, as 3kW only allows me to switch  to inverter on on peak sun hours(i have changeover switch for this purpose) Might even go 1.5kw element, which will even make it more battery friendly.  

On your note on element short, does that occur in practice? 

2 hours ago, BritishRacingGreen said:

Thanks, i am currently using a 30A relay for my 3kW geyser, the one they actually use in geyserwise, i am now giving serious consideration to downgrade my element to 2kW,  even in order to make it more friendly to my 5kW inverter system, as 3kW only allows me to switch  to inverter on on peak sun hours(i have changeover switch for this purpose) Might even go 1.5kw element, which will even make it more battery friendly.  

On your note on element short, does that occur in practice? 

I have had a situation where a normal 20A timer just welded when a short took place at the element due to a slow water leak. The MCB only tripped once and blew the fault open circuit. Wiring done before geysers had to be on a E/Leak.

5 hours ago, Scorp007 said:

I had it the topic was not about power measurement but using a Sonoff 16A rating for a 2kW geyser in a save way. The timer function is the key reason.

Hi, I would definitely use the POWR3 25Amp on a geyser. Its quiet large and does not fit in the DB board but can definitely handle the load and has screw terminals. The new POWR320D or POW Elite 20Amp should also work. We are busy testing them now in South Africa condition but it will also take some time to get them certified. It will definitely be alot more cost effective.

6 hours ago, Scorp007 said:

I had it the topic was not about power measurement but using a Sonoff 16A rating for a 2kW geyser in a save way. The timer function is the key reason.

Hi, I would definitely use the POWR3 25Amp on a geyser. Its quiet large and does not fit in the DB board but can definitely handle the load and has screw terminals. The new POWR320D or POW Elite 20Amp should also work. We are busy testing them now in South Africa condition but it will also take some time to get them certified. It will definitely be alot more cost effective. The Sonoff TH Elite 20Amp will also be a good option.

13 hours ago, Scorp007 said:

I have had a situation where a normal 20A timer just welded when a short took place at the element due to a slow water leak. The MCB only tripped once and blew the fault open circuit. Wiring done before geysers had to be on a E/Leak.

I have wired a 20A fuse in my  homebrewed geyser controller in serie with the relay contacts,  i added it tongue in the cheek but now wonders if it is not very important.