JFW Posted June 2, 2022 Share Posted June 2, 2022 (edited) Hi I am preparing for my solar installation. I already have the inverter (Mecer 5KW 48v), and want to do the majority of the installation work myself. I have a qualitfied sparkie that can assist if needed and oversee operations. I have to split my DB into essential and non essential loads, and connect the inverter, batteries, generator etc etc. I have attached my drawing/diagram of what I think should happen. Please feel free to have a look and let me know where I have missed something or messed something up. I did not draw the connections to the actual loads, but they will be there... Also are the values of the Earth Leakages and circuit brakers correct? The main switch and main E/L is what I currently have in my DB board. Cheers! EDITED: An updated version is attached as Solar Diagram 2. Drawing Solar.pdf Solar Diagram 2.pdf Edited June 8, 2022 by JFW Quote Link to comment Share on other sites More sharing options...
Beat Posted June 2, 2022 Share Posted June 2, 2022 2 hours ago, JFW said: Hi I am preparing for my solar installation. I already have the inverter (Mecer 5KW 48v), and want to do the majority of the installation work myself. I have a qualitfied sparkie that can assist if needed and oversee operations. I have to split my DB into essential and non essential loads, and connect the inverter, batteries, generator etc etc. I have attached my drawing/diagram of what I think should happen. Please feel free to have a look and let me know where I have missed something or messed something up. I did not draw the connections to the actual loads, but they will be there... The main error I see is this: If you split the DB in essentials and non essentials you must also split the neutral bar. It will be a challenge to sort out the individual neutral departures and allocate them to the right neutral bar. Otherwise the leakage breakers cannot work correctly. The changeover switches must also switch the neutral. Quote Link to comment Share on other sites More sharing options...
JFW Posted June 2, 2022 Author Share Posted June 2, 2022 2 hours ago, Beat said: The main error I see is this: If you split the DB in essentials and non essentials you must also split the neutral bar. It will be a challenge to sort out the individual neutral departures and allocate them to the right neutral bar. Otherwise the leakage breakers cannot work correctly. The changeover switches must also switch the neutral. Thx. Yes I have read about that as well. I will try to figure that out and make the necessary changes to the drawing. Quote Link to comment Share on other sites More sharing options...
PowerUser Posted June 2, 2022 Share Posted June 2, 2022 No need of that 50A before AC IN of the inverter. On the AC OUT, the EL should be after the changeover, not immediately on the inverter output. Quote Link to comment Share on other sites More sharing options...
CraigL Posted June 2, 2022 Share Posted June 2, 2022 (edited) Neutral bonding after inverter ? Edited June 2, 2022 by CraigL Quote Link to comment Share on other sites More sharing options...
BritishRacingGreen Posted June 2, 2022 Share Posted June 2, 2022 1 hour ago, PowerUser said: No need of that 50A before AC IN of the inverter. On the AC OUT, the EL should be after the changeover, not immediately on the inverter output. Yes. The 50A serves no purpose , unless he wants to isolate mains from the inverter , in which case he should use a double pole isolator instead of the breaker. As far as the ELD is concerned , I think the placement is correct as it is , because there is already an ELD in the mains path. Quote Link to comment Share on other sites More sharing options...
BritishRacingGreen Posted June 2, 2022 Share Posted June 2, 2022 1 hour ago, CraigL said: Neutral bonding after inverter ? That's a good point. The more modern MKS eg MKSIII has built in bonding relay inside the machine. Older models may not have it. The OP should verify this , by running the inverter purely on battery with input mains disconnected , and then try to trip the inverter ELD by test button. JFW 1 Quote Link to comment Share on other sites More sharing options...
JFW Posted June 3, 2022 Author Share Posted June 3, 2022 (edited) 12 hours ago, PowerUser said: No need of that 50A before AC IN of the inverter. On the AC OUT, the EL should be after the changeover, not immediately on the inverter output. I thought of the 50A breaker as some sort of protection for the Inverter. 12 hours ago, CraigL said: Neutral bonding after inverter ? I wil look into this. Thank you. Edited June 3, 2022 by JFW Quote Link to comment Share on other sites More sharing options...
BritishRacingGreen Posted June 3, 2022 Share Posted June 3, 2022 (edited) db_schematic_non_controlled.pdf 1 hour ago, JFW said: I thought of the 50A breaker as some sort of protection for the Inverter. I wil look into this. Thank you. Hi @JFW That is a good argument . But we must remember that the inverter is a electronic device , a slow circuit breaker is never going to prevent damage in this device . The inverter basically looks after itself in two ways . (a) it has electronic limit control over input current and in the event of that failing it has (b) input fuse built in . This fuse is non-serviceable for consumer. So the main reason for a circuit breaker is not per se for loads , it is there to match to the electrical wire size in its downstream path . The value of the circuit breaker is then calculated with reference to what maximum current the wire thickness can withstand before start burning . This is the COC main concern . Attached please find a uncompleted schematic of my instance at home . You will notice that I have a 32A circuit breaker CB2 that feeds my inverter input . Now the downstream cable is 4mm and for this reason I use CB2 for the sole purpose of protecting this 14 meters cable , not the inverter. In a similar vein , the CB1 40A is there to gear down the 10mm main input to 6mm distribution. db_schematic_non_controlled.pdf Edited June 3, 2022 by BritishRacingGreen Correction Quote Link to comment Share on other sites More sharing options...
JFW Posted June 8, 2022 Author Share Posted June 8, 2022 Thank you for all the input and comments. I have attached an updated version of the drawing based on comments received here. Solar Diagram 2.pdf Quote Link to comment Share on other sites More sharing options...
Speedster Posted June 8, 2022 Share Posted June 8, 2022 On 2022/06/03 at 12:23 PM, BritishRacingGreen said: db_schematic_non_controlled.pdf 359.08 kB · 16 downloads Hi @JFW That is a good argument . But we must remember that the inverter is a electronic device , a slow circuit breaker is never going to prevent damage in this device . The inverter basically looks after itself in two ways . (a) it has electronic limit control over input current and in the event of that failing it has (b) input fuse built in . This fuse is non-serviceable for consumer. So the main reason for a circuit breaker is not per se for loads , it is there to match to the electrical wire size in its downstream path . The value of the circuit breaker is then calculated with reference to what maximum current the wire thickness can withstand before start burning . This is the COC main concern . Attached please find a uncompleted schematic of my instance at home . You will notice that I have a 32A circuit breaker CB2 that feeds my inverter input . Now the downstream cable is 4mm and for this reason I use CB2 for the sole purpose of protecting this 14 meters cable , not the inverter. In a similar vein , the CB1 40A is there to gear down the 10mm main input to 6mm distribution. db_schematic_non_controlled.pdf 359.08 kB · 16 downloads I saw a video where Keith Gough expressly noted the requirement of a circuit breaker before the inverter as they were receiving repair units where some of the internal components had welded together. P1000 1 Quote Link to comment Share on other sites More sharing options...
BritishRacingGreen Posted June 8, 2022 Share Posted June 8, 2022 (edited) The fact that somethin got welded infers that this inverter got fed without any upstream circuit breaker of accommodating value , which of course is wrong , illegal ,dangerous. However my posted arguments remains valid. If memory serves , is this the guru from the SunSynk company ? Edited June 8, 2022 by BritishRacingGreen Extra info ajvt1001 1 Quote Link to comment Share on other sites More sharing options...
P1000 Posted June 9, 2022 Share Posted June 9, 2022 12 hours ago, BritishRacingGreen said: The fact that somethin got welded infers that this inverter got fed without any upstream circuit breaker of accommodating value , which of course is wrong , illegal ,dangerous. Not necessarily - breakers are slow, they are to protect the cables from catching fire. You can push a lot more current through them than they are rated for for short periods. Fuses are faster, but still the same (ie. a standard fast blow 1A fuse will happily pass through 1.5A indefinitely without blowing, 2A for 1s and 10A for 10ms). Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted June 9, 2022 Share Posted June 9, 2022 13 hours ago, P1000 said: Not necessarily - breakers are slow, they are to protect the cables from catching fire. You can push a lot more current through them than they are rated for for short periods. Fuses are faster, but still the same (ie. a standard fast blow 1A fuse will happily pass through 1.5A indefinitely without blowing, 2A for 1s and 10A for 10ms). Spot on. The thermal side of a circuit breaker needs a long time at about 50% over it's value to trip on heat. Most have a magnetic element as well which will work very fast during short circuits of a few times it's value. Quote Link to comment Share on other sites More sharing options...
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