April 21, 20242 yr Hi guys. I recently connected 4x 455w Solar panels to my RCT VmII 2.5kva inverter. My question is: I noticed that no matter the load. The inverter still uses some Power from utility even though the panels are capable of supplying the loads. I tested this out by switching off AC grid supply to inverter. Then the panel production increases and supplies all the load easily. However with AC grid supply on. Panels produce but not as much and inverter uses utility as well. If I leave AC grid on, I'm still using units on my prepaid meter. If I switch off AC grid during the day, then I don't use any units because panels are doing their job. Am I missing a setting ? Output Priority is set to SOL First Charging priority is set to both solar and utility. All advice will be appreciated. Edited April 21, 20242 yr by Red Falcon
April 21, 20242 yr 1 hour ago, Red Falcon said: Hi guys. I recently connected 4x 455w Solar panels to my RCT VmII 2.5kva inverter. My question is: I noticed that no matter the load. The inverter still uses some Power from utility even though the panels are capable of supplying the loads. I tested this out by switching off AC grid supply to inverter. Then the panel production increases and supplies all the load easily. However with AC grid supply on. Panels produce but not as much and inverter uses utility as well. If I leave AC grid on, I'm still using units on my prepaid meter. If I switch off AC grid during the day, then I don't use any units because panels are doing their job. Am I missing a setting ? Output Priority is set to SOL First Charging priority is set to both solar and utility. All advice will be appreciated. When you mention you are still using grid even with enough solar-is this grid use high enough to power loads or is it perhaps below 40W being the self power used by the inverter. This can be 400-600Wh from grid for self use per day.
April 21, 20242 yr Author High enough for loads. Eg: Grid breaker on Load: 900w: Solar: 300-350 Grid: Supplies the balance Eg: Grid breaker Off Load: 900w Solar : 1.1Kw Grid: OFF
April 21, 20242 yr 25 minutes ago, Red Falcon said: High enough for loads. Eg: Grid breaker on Load: 900w: Solar: 300-350 Grid: Supplies the balance Eg: Grid breaker Off Load: 900w Solar : 1.1Kw Grid: OFF If you don't want to use grid set output priority to SBU( solar,battery utility) then you will charge from grid when no pv and battery soc low. Below graph of settings SBU and solar only.
April 21, 20242 yr 7 minutes ago, TaliaB said: If you don't want to use grid set output priority to SBU( solar,battery utility) then you will charge from grid when no pv and battery soc low. Below graph of settings SBU and solar only. This is what is should be like with no power used for load from the grid. The way I see the problem for @Red Falcon is that there is 1100W available from PV yet for a 900W load the PV drops to 350W and 550W is used from grid. This while his setting is to use PV 1st as priority.
April 22, 20242 yr Author I would also like to know what are my options to monitor my inverter using a pc or raspberry pi. And can I remotely monitor as well ?
April 25, 20242 yr On 2024/04/21 at 10:16 PM, Red Falcon said: I noticed that no matter the load. The inverter still uses some Power from utility even though the panels are capable of supplying the loads. I believe that's normal for your model; it's so that when a load disconnects, you don't immediately push power back into the grid. Some inverters have a setting for this; Axperts don't.
April 25, 20242 yr On 2024/04/22 at 1:49 PM, Red Falcon said: I would also like to know what are my options to monitor my inverter using a pc or raspberry pi. And can I remotely monitor as well ? https://solar-assistant.io Buy Solar Assistant. It is very good. You can buy the software only or preloaded/bundled on a pi (recommend).
May 13, 20242 yr Author Hi guys. Back again with another question. Would it be a good idea to change my geyser element to 1.5kw. So that I can have additonal savings by having it connected to the inverter. My usage during the day is very little. So I thought I could have it make use of some PV power during the day to heat up.
July 16, 20242 yr Author Hi guys. I've decided to try and maximize my savings by turning off AC power to my inverter during the day so that my Inverter only uses solar during thr day. Would it be advisable to add a 30amp smart switch to control power to the Inverter? Will the smart switch trip the RCD? @Coulomb @TaliaB @Scorp007
July 16, 20242 yr 20 minutes ago, Red Falcon said: Hi guys. I've decided to try and maximize my savings by turning off AC power to my inverter during the day so that my Inverter only uses solar during thr day. Would it be advisable to add a 30amp smart switch to control power to the Inverter? Will the smart switch trip the RCD? @Coulomb @TaliaB @Scorp007 I'm not sure if you will have much saving. If there is enough PV then I think PV will be used to power the inverter. This is the case when the inverter itself is switched off the charging side works from PV. No a smart switch is just a switch and cannot cause leakage current to operate the RCD.
July 16, 20242 yr Author Okay. I noticed that I lose a good few prepaid electricity units if I leave eskom connected to inverter during thr day. Even though there is enough PV to supply all loads. So at the moment I switch eskom off during in morning and put it back on just before sunset. That way from 07:00 to 16:35 , I don't use any of my units from prepaid electricity.
July 16, 20242 yr 57 minutes ago, Red Falcon said: Hi guys. I've decided to try and maximize my savings by turning off AC power to my inverter during the day so that my Inverter only uses solar during thr day. Would it be advisable to add a 30amp smart switch to control power to the Inverter? Will the smart switch trip the RCD? @Coulomb @TaliaB @Scorp007 What is your battery capacity in kwh or Ah? If you have enough battery power to last you until pv wakes up you can set set the inverter work mode to SBU(program01) and charging source priority to OSO( program 16) then the inverter will disconnect from utility, no need to install a smart switch to switch utility off. The inverter will switch to utility only when the voltage in setting (12) is reached but remember the inverter will not charge the battery via utility the battery will only charge by means of pv. Edited July 16, 20242 yr by TaliaB
July 16, 20242 yr Author I have 2x 50ah. My battery lasts me till about 2am. So what would be the ideal setup for it.
July 16, 20242 yr 32 minutes ago, Red Falcon said: I have 2x 50ah. My battery lasts me till about 2am. So what would be the ideal setup for it. Your battery capacity is the limiting factor which ever way you look at it you are going to need utility to supplement your load and charging. If you get Solar Assistant you could change charge source priority to SNU during the late afternoon and change it back to OSO in the morning when you have pv but leave ouput source priority on SBU. It is not ideal i would suggest to up your battery capacity to cover your load until the pv is producing power. But then again you might also need to upgrade your pv with the extra battery capacity as you might not cover load and manage to fully charge the batteries before sunset.
July 16, 20242 yr Author My main goal is to prevent the Inverter using eskom during the day because I have more than enough PV to supply my load(very little use) during the day. So I don't even use battery power during the day. I only need utility after sunset. So do I do smart switch or solar assistant for my intended goal Edited July 16, 20242 yr by Red Falcon
July 16, 20242 yr 2 hours ago, Red Falcon said: My main goal is to prevent the Inverter using eskom during the day because I have more than enough PV to supply my load(very little use) during the day. So I don't even use battery power during the day. I only need utility after sunset. I also read your question as only switching grid off during the day and not have to get through the night as grid is on after sunset. I use my inverter without grid connected and can anytime switch the grid on via smart switch. I use only 1 panel to charge the battery and manage my load if connected to inverter. I have just checked my similar inverter. When grid is on and running from the battery after sunset it uses only 2.8W from grid. So not much per day. Some light load connected. It did go on bypass while the inverter stayed on. After switching off and on it switched to SBU. This is when charging is from PV ONLY after sunset.
July 16, 20242 yr Author Okay thanks . That clarifies things. I just don't understand why my units drop so quickly if I leave grid connected to the inverter during the day, even when load is low and PV can easily handle the load. Eg: load on average during thr day is 300w. Pv: I have 1.8Kw capacity installed.
July 16, 20242 yr 28 minutes ago, Red Falcon said: Okay thanks . That clarifies things. I just don't understand why my units drop so quickly if I leave grid connected to the inverter during the day, even when load is low and PV can easily handle the load. Eg: load on average during thr day is 300w. Pv: I have 1.8Kw capacity installed. What is your bulk charge CV voltage(26) and float charging voltage(27) set to? As soon as you reach float charging voltage it will trigger absorption( CV) and your current will start to drop using less and less from the pv. So check that the float and bulk is not set far apart. For 24v battery set bulk to 27.6v and float to 27.3v
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