Matt Bird Posted August 6 Share Posted August 6 (edited) Hi community, I have a 1PM wired up to switch a contactor (Finder 22.32.0.230.4340) for a hot water system. When the contactor is in "On" mode, the 1PM works just fine (though doesn't switch the load as the coil is 'ignored'). When in Auto, the 1PM seems to just hang for 10 secs or so when trying to operate the contactor, before seemingly coming back to life, but without doing anything. I'm wondering if the contactor coil is enough of an inductive load to cause the 1PM to reboot? Should I try an RC snubber? And if so, I assume it would be placed in parallel with the contactor's A1 A2 control circuit? Thanks in advance for your assistance! Matt. Edited August 6 by Matt Bird Quote Link to comment Share on other sites More sharing options...
Shelly Olsche Posted August 6 Shelly Share Posted August 6 Is the installed firmware the latest available? Current version is 1.4.0. Otherwise, an RC snubber can be helpful, connected as you described in parallel to the load (A1/A2) Quote Link to comment Share on other sites More sharing options...
Matt Bird Posted August 7 Author Share Posted August 7 Thanks Olshe - the firmware was out of date, but after updating did not solve the issue. Will try with the snubber and report back. Quote Link to comment Share on other sites More sharing options...
Matt Bird Posted August 15 Author Share Posted August 15 Hmmm - no luck with adding in a snubber. I'm at a bit of a loss as to why it won't switch the contactor. I've gone over my wiring again and seems to be OK. The issue only presents in the AUTO position on the contactor. I can get the contactor to operate once from ON to OFF by energising A1 to A2 with the 1PM with the contactor in "On" mode before moving it to "Auto" mode, then de-energising A1 to A2. After that, the 1PM becomes unresponsive, though is still shown as online in the app. Note that the load is hot water, which is also controlled by a thermstat, so it may be that there is no load present at time of switching (water already heated). That shouldn't matter should it? I've attached a photo. It doesn't show the wiring back to the breaker as the contactor is in a seperate box. My only other ideas are to run some tests with a light bulb or something... Or assume the Shelly 1PM is faulty and get a Shelly Pro EM 50. What else could I do? Quote Link to comment Share on other sites More sharing options...
tvbshelly Posted August 15 Share Posted August 15 It would be great if you could draw us a circuit diagram. Your wiring is not quite clear to me. @Matt Bird Quote Link to comment Share on other sites More sharing options...
tvbshelly Posted August 15 Share Posted August 15 6 hours ago, Matt Bird said: Or assume the Shelly 1PM is faulty and get a Shelly Pro EM 50. I find that a bit confusing: A Shelly 1PM and a PRO EM-50 are quite different. With the 1PM you can switch and measure power, with the PRO EM-50 you can only measure power (but not switch). What exactly do you want to achieve? Actively switch and measure with a Shelly or just measure consumption? Quote Link to comment Share on other sites More sharing options...
Members thgoebel Posted August 15 Members Share Posted August 15 (edited) A Shelly pro EM50 has a relay! Edited August 15 by thgoebel 1 Quote Link to comment Share on other sites More sharing options...
tvbshelly Posted August 15 Share Posted August 15 (edited) 14 minutes ago, thgoebel said: A Shelly pro EM50 has relay! Oh, sorry, of course you are right. I was just thinking of the Pro 3EM (for which you need the add-on to be able to switch with it). Edited August 15 by tvbshelly Quote Link to comment Share on other sites More sharing options...
Matt Bird Posted August 15 Author Share Posted August 15 (edited) Thanks for your comments. Quote What exactly do you want to achieve? Actively switch and measure with a Shelly or just measure consumption? I'm wanting to switch a 3.2kW hot water system. I originally had the 1PM in series with the hot water system, which worked fine, but had over temperature issues. I've attached a wiring diagram. Note in the photo the circuit breaker is not show and you can disregard the MSN140 and smart meter, they're for a solar PV system. Oringially the inverter was meant to switch a 12V coil contactor, but wasn't working. Any suggestions most welcome! Edited August 16 by Matt Bird 1 Quote Link to comment Share on other sites More sharing options...
tvbshelly Posted August 16 Share Posted August 16 Thanks for taking the time to do the wiring diagram. In my opinion, the wiring is absolutely correct. It should actually work that easily. Really strange. Do you have the possibility to measure the current flow on the cable between Shelly and Snubber connected at A1 or A2 with a current clamp (it should be able to do True RMS and have Max or better Inrush mode)? However, it is often not easy to determine switch-off peaks or inrush currents with a current clamp - but this might give a clue. Quote Link to comment Share on other sites More sharing options...
tvbshelly Posted August 16 Share Posted August 16 (edited) On 15.8.2024 at 05:32, Matt Bird said: After that, the 1PM becomes unresponsive, though is still shown as online in the app. A question about “Shelly is unresponsive”: A new test would be great, in which you try to access the WebUI directly during this time - Can you access the Shelly directly via http://<shelly-ip> - is the WebUI active or completely offline? Edited August 16 by tvbshelly Quote Link to comment Share on other sites More sharing options...
Matt Bird Posted August 21 Author Share Posted August 21 On 8/16/2024 at 7:48 PM, tvbshelly said: A question about “Shelly is unresponsive”: A new test would be great, in which you try to access the WebUI directly during this time - Can you access the Shelly directly via http://<shelly-ip> - is the WebUI active or completely offline? Thanks for the advice. Pleased to report that I have finally resolved this issue. Using the WebUI helped me see more clearly that the Shelly was going completely offline (the app still indicated it was being switched, just with a lot of lag). This indicated the Shelly was not receiving power once the contactor opened - so the shelly must have been in series with the contactor rather than parallel. So I went back and physically checked the wiring. To my surprise, the CB was not actually connected directly to the contactor. Maybe the contactor is on the other side of the load - not sure. In any case I ran a new wire from the CB to the Shelly and it is working now. Thanks for your help. 2 Quote Link to comment Share on other sites More sharing options...
tvbshelly Posted August 21 Share Posted August 21 Great that it works now 🎉 Wiring is often a problem 1 Quote Link to comment Share on other sites More sharing options...
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