Scarlock

Thanks for the explanation! It makes much more sense now and it looks like it is just "easier" for my electrician to just insist on a separate DB by "bending the truth" a bit... unfortunately for him I don't take kindly to bovine excrement... Time to rewire the main DB 😁

Hello, I am doing the final planning for a solar backup system and have been told that all my AC breakers cannot be housed in the same physical DB, as it would contravene the SANS codes. I was told that "you cannot have more than one source of power" in a single DB, but this makes no sense because you have to have multiple "sources" for a selector or changeover. As I do not have a copy of the SANS I cannot verify what is and is not actually allowed in my DB. I have attached a quick system diagram, and would like to know if it is possible to legally house all my AC breakers in one large DB box, and if so what rules I need to follow. Any insight would be great.WD01-1.pdf Thanks

Hello everyone, I am putting together a home off-grid style system (first time doing so), and have had endless "issues" with trying to have a professional install a system in any reasonable length of time or price. I seem to think I have a reasonable understanding of electrical theory, and enough common sense to write this post instead of simply trying things Russian style and hope they don't blow up. When asking technical question of professional installers who should know these things, I end up with blank stares which doesn't exactly instill a sense of confidence in me. At this point I want to know exactly what the correct configuration is supposed to be, and simply have my normal electrician inspect and sign off the build. Primarily I am having a hard time trying to find the simplest, yet safe way to setup the Earth/Neutral bonding so that I do not get a residual charge build up when Eishkom is loadshedding, which then causes the earth leakage to trip as soon as the mains in power is restored. The system is not yet installed, but I have had to deal with other systems that have this problem and don't want that headache at home. I am specifically trying to avoid using an earth bonding relay if possible, and at this point in time I have read so many conflicting opinions, that I am now thoroughly confused 😛 I do know (if it is even accurate) that the primary municipal earth/neutral bond is at the transformer, and that you are not allowed to rely on this bond for your house, and that a separate earth spike needs to be bonded in your main DB to ground your system. I do not know where and how the primary earth/neutral bond is done in the main DB. The system is as follows: 1x Victron MultiPlus-II 48/5000 1x Victron SmartSolar MPPT 150/60 1x Victron Cerbo GX 1x Victron Lynx Distributor 2x Hubble AM2 Batteries 6x CA605W Panels Preliminary DB Configuration: Main DB + Sub DB Main DB a. Direct Utility supply on Mains breaker -> Earth Leakage -> Inverter breaker. (possibly oven & Geyser as well) b. All other house circuits fed from off-grid Sub DB Sub DB 2 Pole, 3 position Selector -> Utility side supply bonds neutral bar to Main DB neutral bar & live to Main breaker out. 2 Pole, 3 position Selector -> Off-grid side supply bonds neutral bar to inverter neutral out & live to inverter live out. 2 x Lights breaker (before earth leakage) Earth Leakage -> All other house circuits. Question 1: I am assuming the main DB earth leakage is still required because it is powering the inverter AC input which needs protection. Question 2: Is the selector configuration correct, or am I missing something on how the neutrals are connected in either position. Question 3: Where do I bond the damn earth connections? I can simply bond the Sub DB earth to the Main DB earth in a permanent connection? This is where I fall short trying to figure out where, or if I need to bond earth/neutral to prevent residual charge build up. I do not know if the inverter has an auto/permanent earth/neutral bond, or if a fixed earth/neutral bond will cause a problem when the utility power is down or when it returns. Answer: Victron have an internal relay that bonds the inverter output neutral to the chassis earth when the AC input relays are opened. No external bonding needed, but chassis earth MUST be connected correctly. Any insight would be appreciated, so that I can avoid endless call out fee's trying to reconfigure the system over and over again. Thanks ~Scarlock