Fuenkli

you can use the long "battery to inverter" cable you received with each battery. It has the same connectors and pinout.

no I did not . Never received a reply to my follow up e-mail (see below). Based on @plonkster's very good summary and risks of the available options I have bridged the neutrals. Dear David, thank you for the reply. According to SANS, bridging neutral/earth is illegal. We had a long discussion on "Power Forum" how to solve this problem (see below). What do you suggest we do? Regards Juerg On 2020/02/08 at 4:21 PM, Fuenkli said: 1. do nothing. What is the risk? In my estimation the risk is low. Your neutral becomes a "hot" conductor (one might say), but if touching it causes enough current to flow to exceed 20mA-30mA, the RCD will still trip. With that said, I must still note that this would not be SANS compliant. SANS requires an islanded system to bond T and N. On 2020/02/08 at 4:21 PM, Fuenkli said: 2. Permanently bond neutral to earth on the back up output. If I remember correctly this is illegal because it creates a second neutral earth bond 3. Connect the inverter in and out neutrals. Probably also illegal because you loose the earth connection when the grid is down or the main switch is switched off. Both these are not allowed by SANS. Bridging the neutrals would probably be the lesser evil, 1) because Goodwe advises that you do this, and 2) apparently it is allowed in Australia. You won't lose the bond when there is a grid outage, but you might if your main breaker trips (which disconnects the neutral) or if you switch it off for any reason. Probably better than nothing, but not perfect. On 2020/02/08 at 4:21 PM, Fuenkli said: 4. Install an external bonding relay. I am not sure how one would do this and how much this would cost. In my view this is the only proper way to do it, and ideally one would want the inverter itself to signal this (like the bonding relay box that's turned on by the internal relay in the Axpert). Only, I don't think the Goodwe has any way to signal such a relay. One potential way is to use a contactor with 2 x N/O and (at least) 1 x N/C contacts. Use the two N/O contacts to switch the grid to the inverter, and the N/C to make a bond on the output. Let the grid pull in the contactor, that is, when there is a grid outage the contactor drops out. The reason for actually switching the grid connection through the contactor is to mechanically interlock this operation: It would be impossible for the bond to be applied if the grid isn't also disconnected. Downsides to this scheme: 1. If the voltage is out of range, but high enough to pull in the contactor, the inverter might switch to islanding mode while the bond remains unapplied. 2. NRS097 mandates a 60 second monitoring window after the grid returns. If the voltage/frequency remains stable in this 60 seconds, the inverter will connect back to the grid. The trouble with this: When the grid returns the bonding is removed, but for another 60 seconds the output will remain floating. Which gets me back to my point that ideally, one would like the inverter itself to signal islanding mode in some manner.

I bought mine at Rubicon

might be a problem if the inverter is on fire .

I agree with @DeepBass9. There has to be a dodgy connection in either the neutral or live wires of the affected circuit. I would first check if there is power after the circuit breaker supplying the lights in questions. If this is ok go and find the neutral wire in the DB for the lights and check it. If live and neutral are ok in the DB you have to follow them throughout the house until you find the point where the interruption is.

I had to do the same. But I guess it will depend on what type of panel clamping hardware you use. Goodwe recommends a maximum resistance of 20kOhm between panel and ground.

that is not good. Either Goodwe has changed the specifications or your inverter is faulty. I would take this up with the installer or directly with Goodwe. David Havenga (Southern Africa Goodwe rep) is usually very helpful. [email protected]

it is in "Basic Setting". After you set the inverter "Mode" and "Battery Model" the next screen lets you define all the required battery charge and discharge parameters including charge current. I am using EZManage at the moment (PV Master stopped working on my phone) but it used to be the same on PV Master the last time I used it. But as I said before maybe the option does not exist if you are not managing the battery with "self define".

if i put my Goodwe ES inverter into "back up" mode the default battery charge power from the grid is around what @Bobsterhas observed. But i can increase it all the way up to 100A with the PV Master or EZManage app. My battery is managed as "self define" maybe this is not possible if you have a communication link between the battery and the inverter.

Yes that is also how I read the specification sheet I think you are right. Although the back up is connected via the relay array to the grid (see attached diagram) it will disconnect if the load is >4.6kVA . I have never managed to trip the back up output during normal grid operation. Maybe there is a Goodwe ES inverter owner here on PF who did, and can confirm if our theory is correct.

I agree. PV in combination with a heat pump is a very good solution. Maybe I misunderstood you regarding your friends. I thought they have heat pumps without PV.

we discussed this a while ago. It looks like that newer Goodwe ES inverters can now pass through power from the grid to the back up output. Have a look here (topic is discussed at the end of the page): https://powerforum.co.za/topic/4272-victron-easysolar-5kva-or-goodwe-5048d-es/

I agree that heat pumps work very well, but they still use electricity . If you have surplus PV power to cover the requirement for most of the year it is ok (might be slightly more expensive than a Solar Geyser for some households). But my view is, that you should NEVER use only dirty Eskom power to heat water in a sunny country like South Africa.

yes it is possible. But if you have maxed out your PV systems legal and technical capabilities and it does not give you free hot water for most of the year then adding a solar hot water system would probably be the best option.

I agree. Provided that all you have to do is to invest in more PV generation capacity. Unfortunately this route is because of the SSEG rules not possible for everybody (including me).