Fuenkli

I would go with a hybrid GTI. Yes battery storage at the moment is more expensive than Eskom, but this will soon change. In addition there is another trend taking place in the industrialized world and I think will also come to SA. The power producers/distributers are offering the customers very attractive feed in tariffs whenever they are short of power. This is usually the case in the early morning and late afternoon peak consumption period. To be able to take advantage of this opportunity you need batteries. (Or an electric car 😁).

Thanks Jaco for mentioning this. In my installation the AC and DC wires run in the same trunking. To change this would be a huge project. When you say "should" does this mean that it is not a legal requirement but only a guidline?

Is it ok/safe/legal to connect the inverter back up (UPS) neutral on a Goodwe ES inverter to the grid neutral? Basically in line with the Aussie (MEN) requirement (see attachment). The advantage of this is that only one neutral wire between inverter and DB board is required.

please be aware that if you have a single phase 60A Eskom power supply this inverter is exceeding the maximum kW allowed by most municipalities.

you can not harvest watts (power). You can only harvest watt hours (energy).

I agree, Grid tied without export is the way to go. The only problem (even with batteries) is how to use as much of the available PV output as possible. As far as I know there is still no automatic smart power diverter/management system available for GTI's set to zero export. The result of this is, that a lot of available PV is wasted.

I agree. It is just to prove the point Silver made. The Sparky saved a few Rand. I guess it is legal but a huge inconvenience for the house owner.

I agree. My house is brand new (moved in 2 years ago). The Bosch induction Hob alone keeps tripping the 20A CB it is on. I have a big problem with my wife because she thinks it is all because of the PV system .

yes it is the solid square neutral bar. I will do what you do and enlarge one hole to accept the 16mm2 cable. Strange that they fit neutral bars like this.

I have a single phase Eskom power supply with a 60A main switch. What is the minimum wire size inside the DB board from the main switch to the RCD's and bus bar's? I thought it should be at least 16mm2 but the neutral bus bar holes are only big enough for a 10mm2 cable.

We found the short between neutral and ground. What a mission! We followed Plonkster's advice to go from light fitting to light fitting disconnecting the neutrals until we found this (see attached picture). The wire holding clamp put to much pressure on the neutral wire and connected it with the ground wire. I think this is a design problem of the fitting. It should not be possible to put so much pressure on the wires. I learned a lot about neutral earth fault finding. Thanks for all the input.

the short between neutral and earth is inside the house. We disconnected the house from the grid and there is still a dead short. We are presently checking every light connection of the lights which are on even without a neutral connection to the DB. Hopefully we will be able to narrow the fault down further.

yes this is what we did. Also measured the resistance between neutral and ground (with the DB board completely isolated from neutral) and we have a total short. I agree we have to sort this out. Told the sparky to keep on looking. Will use some of your suggestions.

I have a Neutral Earth fault in my house I can not find. The fault was only identified when we moved all the lights onto the RCD protected UPS section off the DB (before they were wired without an RCD which I guess is the local standard to safe cost). I have narrowed down the section of the house where the problem is (some lights still on even with all neutrals disconnected). Because the wiring of this section of the house is almost inaccessible (very low roof space) we are about to give up. What would be the risk of leaving it as it is and just separate the UPS section of the DB board into an RCD protected section for the plugs and one without for the lights?

in my case it was not possible because the cable from the muni box to my house is only rated for 60A.

does this also apply to a grid tied system without power export?

I thought you only pay the daily charge if you want to sell electricity to the CoCT.

The surge protector in my DB Board has an LED light. If I fit another one in the UPS section of the DB Board would that qualify as a power indicator/pilot warning light?

true, but a city has to be careful not to disillusion/abandon the part of the population it desperately needs to become/remain a world class city. People will vote with their feet and simply leave town accelerating the downward spiral. We have to find a win win situation. I think technology will be the answer. Locally produced and stored electricity will become much cheaper in the future leading to huge distribution and maintenance cost savings for the city. In the future successful cities and countries will no longer rely on income from selling electricity and water. This will be the responsibility of the private sector. The income of the city/country should only come from taxes.

fortunately this is not a problem with a GTI. The power just comes from the grid instead of from the inverter. Did some data research after reading Plonkster's reply. What I found out is that the inverter's SOC calculation is always a bit to optimistic (ok this is only based on measuring the voltage of the batteries because I do not have a BMV). So if I reduce the Battery capacity setting to lets say 350Ah instead of 400Ah maybe the SOC calculation will be more accurate and the error condition will not occur anymore.

thanks Plonkster for the reply. Makes sense what you say. I will just ignore the error message. I hope the shut downs and restarts will not stress the inverter.

my inverter (Goodwe GW5048D-ES) sometimes (+- once a week) shuts down and restarts reporting the error "SOC delta over range. Please check the battery capacity setting and charge voltage setting". It always happens in the morning when the batteries start charging. Goodwe customer support told me that if my battery capacity and charge voltages have been set correctly there is nothing to worry about it and I can ignore the message. The settings are as follows: battery capacity: 400Ah bulk current: 50A (this is the inverter limit although the batteries could take 200A according to the spec sheet) absorb voltage: 57.1V (56.8 measured on batteries) tail current: 4A (1%) tail current time < 4A before going to float: 20 minutes float voltage: 54.6: (54.2 measured on batteries) what do you think causes this error message? What can I do to prevent this from happening? Maybe I can ask the Goodwe engineers what parameters the code uses to determine the fault condition.

thank you pilotfish for the information.

We are busy separating the DB board into a normal and back up (UPS) section. What are the legal requirements regarding labelling to indicate that the back up (UPS) section will still be live in case of a power failure or if the main switch is switched off? Is it also required to have a visual (light) indicator to show that this section of the DB Board is still live?

what do you regard as a safe maximum discharge rate? The highest battery discharge current I have is 100A on a 400Ah bank. This kind of load usually occurs for only very short periods of time (<1 minute) and only a few times a week. Do you think this is safe or should I change my system to reduce the maximum load on the batteries? The batteries are Lead Carbon VRLA AGM's.