The option under NRS097 grid code settings: Reconnect power rate: 100% per 600 seconds.
What does it mean?
It takes +-65sec for the inverter to sync with the grid after it came back on.
I'm looking to extend the waiting period to 5 minutes before it reconnects with the grid.
Or must I rather install this: https://surgeprotection.co.za/products/12-01036-tripconnect-1p
Feedback would be appreciated.
It is my opinion that Victron has not implemented NRS completely. It should allow us to specify a “utility provided” reconnect time / delay which we are not able to do.
I am also extending the time until reconnection. I have not seen an option to do this with Victron equipment. I am using for that a monitoring relay https://www.benderinc.com/products/mess-und-ueberwachungsrelais/linetraxx-vme420 and a contactor at the AC input of Multiplus 2. This is completely separate from the Victron equipment.
Before the power becomes stable after one of the brownouts, power from some suppliers is repeatedly coming back and switched off again. There are also voltage spikes that destroy electrical equipment when the power is restored. Companies like Sollatek provide monitoring relays with loads up to 100 A that can introduce a reconnection delay until the grid has hopefully become stable again. https://www.sollatek.com/product-category/single-phase/
My interpretation would be that they are expecting the inverter power to be ramped up slowly over the 10 minute period. So an inverter should take about 2 minutes to allow the grid to settle and synchronise, then the power should be ramped from 0% to 100% over the remaining 8 minutes. This will allow the grid authority to control and stabilise it's generation.
Makes sense if that is the case.
Relays are being damaged left right and center when the power comes back on or worse, the transformer in the street develops a problem when load-shedding is over and gets overloaded, repeatedly.
Ideally, following on on what @Rainer and @Warwick Bruce Chapman said, the inverter should stay far away from the grid when load-shedding is over, to at least slow down repairs, or worse, damage to Victron inverters.
Once power returns, keep the grid away from the system for x amount of minutes, user adjustable. After the time has elapsed, then only connect and sync to the grid again. Would not stop drama on the main DB, but it would protect Victron inverters and the critical loads connected to them.
It is disastrous when one's unit gets damaged and then has to wait a while for repairs/warranty replacement.
From: NRS097-2-1 (2017)
1. Emphasis here is on the word "may" in 4.2.4.2.1.
2. 4.2.4.2.2. specifies 60s to 600s (10 mins) but it does not require reconnection within those parameters. (Again, the use of "may").
3. 4.2.4.2.1 Also "requires" that there be an "option of changing this to a utility provided setting". This is absent from the Victron implementation.
4. by implementing a configurable reconnect delay on n seconds (where n can be > 600), the firmware would be more compliant with NRS097-2-1.
If such a change will trigger re-certification, then I propose ahead of a future re-certification event, this change be queued until then.
