Ernie Posted July 20, 2019 Share Posted July 20, 2019 I'm sure this has been covered somewhere but I can't find it. Is it safe to put a 100L geyser with a 2kW element on a 16A Sonoff switch? What would the surge power be for this element? Quote Link to comment Share on other sites More sharing options...
Jaco De Jongh Posted July 20, 2019 Share Posted July 20, 2019 23 minutes ago, Ernie said: Is it safe to put a 100L geyser with a 2kW element on a 16A Sonoff switch? Yes, the 2kw will draw approximately 8 Amps (Halve of the Sonoff's rating.) 23 minutes ago, Ernie said: What would the surge power be for this element? Resistive loads have very little inrush current. When applying power to the element, the current will basically rise to its max and remain there. Its not like motors that can draw up to 7 times the rated current during startup. You dont have to worry about surges in this application. GVC 1 Quote Link to comment Share on other sites More sharing options...
Ernie Posted July 20, 2019 Author Share Posted July 20, 2019 Thanks! Quote Link to comment Share on other sites More sharing options...
MartinCoetzee Posted July 21, 2019 Share Posted July 21, 2019 i put mine through a 2ndary relay to take the load. its been running more than a year. Quote Link to comment Share on other sites More sharing options...
Jaco De Jongh Posted July 21, 2019 Share Posted July 21, 2019 5 hours ago, MartinCoetzee said: i put mine through a 2ndary relay to take the load. Rating? Quote Link to comment Share on other sites More sharing options...
Chris Louw Posted July 21, 2019 Share Posted July 21, 2019 4 hours ago, Jaco de Jongh said: Rating? Made a 30 amp relay same as Geyser wise control box . Quote Link to comment Share on other sites More sharing options...
MartinCoetzee Posted July 22, 2019 Share Posted July 22, 2019 yeh i also used a 3o amp. Quote Link to comment Share on other sites More sharing options...
Luminous Posted July 22, 2019 Share Posted July 22, 2019 On 2019/07/20 at 8:50 AM, Ernie said: I'm sure this has been covered somewhere but I can't find it. Is it safe to put a 100L geyser with a 2kW element on a 16A Sonoff switch? What would the surge power be for this element? Why don't you spend the extra R30 and get the Sonoff POW R2 then you can also measure the power usage on the geyser? Quote Link to comment Share on other sites More sharing options...
Ernie Posted July 22, 2019 Author Share Posted July 22, 2019 That is the one Im getting thanks Quote Link to comment Share on other sites More sharing options...
PaBz0r Posted August 1, 2019 Share Posted August 1, 2019 Which relays are you guys using @Chris Louw @MartinCoetzee? I see that this is the way to go for the geyser as the sonoffs tend to burn if connected directly, apparently the 16A rating is not worth much.. Quote Link to comment Share on other sites More sharing options...
Chris Louw Posted August 1, 2019 Share Posted August 1, 2019 5 hours ago, PaBz0r said: Which relays are you guys using @Chris Louw @MartinCoetzee? I see that this is the way to go for the geyser as the sonoffs tend to burn if connected directly, apparently the 16A rating is not worth much.. Used a relay from a Geyserwise controller . 30 amp 12 volt input . Had one from a unit which was struck by lightning . Made a small cotrole box with 12 v witch is switched by Son off . Bought nothing , all stuff that was available . Quote Link to comment Share on other sites More sharing options...
Chris Louw Posted August 1, 2019 Share Posted August 1, 2019 On 2019/07/22 at 7:47 AM, Luminous said: Why don't you spend the extra R30 and get the Sonoff POW R2 then you can also measure the power usage on the geyser? With the Pow 2 there are power limits witch is adjustable Min Max watts and amps . This is quite accurate . Keep start up currents in mind . Starting fridges will switch the Sonoff off if set to low . Quote Link to comment Share on other sites More sharing options...
PaBz0r Posted August 22, 2019 Share Posted August 22, 2019 (edited) 13 hours ago, Pietpower said: They say 16A for the POW R2 in the adds but on the unit it says 15A 13A for a 3kW geyser element direct on the 15A sonoff is a bit close for comfort. Bigger problem is the wire connectors are not made or strong enough to grip the thick wiring properly (twin&earth) Also looking for a contactor made for installation outside of a db board to install in a york box with the sonoff next to the geyser. Was also thinking it is a bit close for comfort. I am not sure of these relays, some state low voltage switching, from my understanding the Sonoff does not have low voltage switching, something like a Shelly does, but not really available without importing. Do you maybe have an idea of which relays will work with a Sonoff? If can't use the POW R2, I will use it to switch on an extractor fan where my install is located based on temperature. I understand that they have temperature switching probe, but I am going to try and do it using the battery temperature that I get from the MQTT feed of the Venus. I have setup a node red install and it seems that it will not be tricky to get that specific flow going. Edited August 22, 2019 by PaBz0r Quote Link to comment Share on other sites More sharing options...
Gerrie Posted August 22, 2019 Share Posted August 22, 2019 3 hours ago, Pietpower said: The contacts are light and they burn easily when you switch high voltage and high current. Yes, I also think these relays are to small for heavy loads I would only use the sonoff in my control circuit on a little 5A breaker and let a contactor do the heavy work with its own breaker. One thing is don’t run out of data on your wifi otherwise the Sonoff’s timer function won’t work on your phone, as what happened to me today, my solar never switched to off-grid this morning at 08h00 because we ran out of data at home. Quote Link to comment Share on other sites More sharing options...
louwng Posted November 6, 2019 Share Posted November 6, 2019 On 2019/08/01 at 3:32 PM, Chris Louw said: Used a relay from a Geyserwise controller . 30 amp 12 volt input . Had one from a unit which was struck by lightning . Made a small cotrole box with 12 v witch is switched by Son off . Bought nothing , all stuff that was available . On 2019/08/01 at 3:32 PM, Chris Louw said: Used a relay from a Geyserwise controller . 30 amp 12 volt input . Had one from a unit which was struck by lightning . Made a small cotrole box with 12 v witch is switched by Son off . Bought nothing , all stuff that was available . Using the Geyserwise relay do you still get the power usage reading from the sonoff as the current is now drawn thru the 30A relay Quote Link to comment Share on other sites More sharing options...
Chris Louw Posted November 6, 2019 Share Posted November 6, 2019 2 hours ago, louwng said: Using the Geyserwise relay do you still get the power usage reading from the sonoff as the current is now drawn thru the 30A relay I am using the 10 amp Sonoff to switch the relay . This 10 amp Sonoff does not give any readings . The power flows through the relays not the Sonoff , no reading will be avialable even if you use the 16 amp as a switch for the relay . Quote Link to comment Share on other sites More sharing options...
SassK Posted January 5, 2020 Share Posted January 5, 2020 (edited) On 2019/07/21 at 1:04 PM, MartinCoetzee said: i put mine through a 2ndary relay to take the load. its been running more than a year. Hi Guys, need help and advice adding relay to my setup. I am currently using a Sonoff POW R2 on my 200lt geyser which just burnt out today after 7 months. The Live output connector burnt out as shown in pic. I have another on a 100lt geyser also running for 7 months and that is working fine. I have had a look at it and has no signs of burn on connector. @ Martincoetzee and Chris Louw , will you be able to post a pics of your relay setup? Or if anybody else can send me pics. Will buy another Sonoff this week, but need advice as to which relay to buy and how to install. TIA. Edited January 5, 2020 by SassK Quote Link to comment Share on other sites More sharing options...
Chris Louw Posted January 6, 2020 Share Posted January 6, 2020 17 hours ago, SassK said: Hi Guys, need help and advice adding relay to my setup. I am currently using a Sonoff POW R2 on my 200lt geyser which just burnt out today after 7 months. The Live output connector burnt out as shown in pic. I have another on a 100lt geyser also running for 7 months and that is working fine. I have had a look at it and has no signs of burn on connector. @ Martincoetzee and Chris Louw , will you be able to post a pics of your relay setup? Or if anybody else can send me pics. Will buy another Sonoff this week, but need advice as to which relay to buy and how to install. TIA. I use 2 of these relays for live and neutral . The 220 to 12 vdc power supply is a unit that was lying in the bin , use The Son off basic , works fine . Ingo 1 Quote Link to comment Share on other sites More sharing options...
Faniedup Posted January 6, 2020 Share Posted January 6, 2020 A relay on the Sonoff is a must, the photo shows what's left of a Sonoff POW R2 connected to a 2kW element after 6 weeks use. Quote Link to comment Share on other sites More sharing options...
SassK Posted January 7, 2020 Share Posted January 7, 2020 15 hours ago, Chris Louw said: I use 2 of these relays for live and neutral . The 220 to 12 vdc power supply is a unit that was lying in the bin , use The Son off basic , works fine . Thank You Chris, will give it a go this weekend. Quote Link to comment Share on other sites More sharing options...
SYC Posted January 7, 2020 Share Posted January 7, 2020 I stand to be corrected but connection should be: (Sonoff should NOT be inline) Hope this helps someone or answers why relay burnt Chris Hobson 1 Quote Link to comment Share on other sites More sharing options...
SYC Posted January 7, 2020 Share Posted January 7, 2020 (edited) Sourced from Communica Edited January 7, 2020 by Quat Allah Al Shams forgot source Quote Link to comment Share on other sites More sharing options...
Chris Louw Posted January 7, 2020 Share Posted January 7, 2020 2 hours ago, Quat Allah Al Shams said: I stand to be corrected but connection should be: (Sonoff should NOT be inline) Hope this helps someone or answers why relay burnt That is correct the 220 v to the geyser only goes through the 30 Amp relay . Sorry if the drawing is not clear . 220 v Supply for the geyser from the right . Sonoff separate supply from left . Relay uses 0.9 amp . Son off should last a long time . Quote Link to comment Share on other sites More sharing options...
Stalky Posted January 30, 2020 Share Posted January 30, 2020 Hi. All the photos seem to indicate that the burning involves the connectors for the wires, and not actually the relay on the POW R2 board itself. Is this the case? If so, maybe there is a way to improve the connection so that it does not overheat from arcing or poor contact. Comments? From Stalky (New Sonoff user) Quote Link to comment Share on other sites More sharing options...
Riaanh Posted January 30, 2020 Share Posted January 30, 2020 20 minutes ago, Stalky said: Hi. All the photos seem to indicate that the burning involves the connectors for the wires, My first observation as well. I have one that burnt the tracks below on a 3kW load after about 6 months. I now rather use the Sonoff to simply switch a contactor. No need for 12V supply or the likes. Contactors are made for that. The only issue is yes you loose the Power consumption graph and log functionality. Quote Link to comment Share on other sites More sharing options...
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