MuKi

Thanks, I see this does not have a aux contact to feed back to inverter via an aux contact? As per part b of appendix 4. But if you guys have managed to get it approved with this, then will go this route. thanks for your assistance.

Hi There everyone, I hope someone has a definitive answer for this question. Is there an off the shelf product which complies to the requirement of COCT appendix 4 for an suitable interlock changeover switch? I can’t seem to find any off the shelf that complies with everything. I have emailed COCT but they have said they do not have a list of approved change overs. If a off the shelf switch does not exist? How do you comply with COCT regulations or how do you get it approved?

Would also recommend to make sure that the breaker and wires are sized correctly. And circuits are identified properly. i.e. if you switch a light circuit off that only lights and not plugs go off, I had both these problems when COC was done on my new place. If COC done recently, then you should be good to go.

In this scenario i feel it would logical to have an changeover switch as the inverter would be able to backfeed into the grid as it does not know the difference. The setups I have seen all have the grid connected to the inverter and the output of the inverter connected to load, so no chance of the inverter feeding back onto the grid.

Which items are you looking for

Do you perhaps have a link to this extension?

Electro Mechanica.

I'm not sure I understand this diagram, please amuse my ignorance. Case 1: grid is on, changeover connecting grid to backup DB. Inverter doenst then feed anything. Case 2: grid is on, changeover connecting inverter to backup DB. Inverter feeds backup db. Then if grid goes down, anti-islanding kicks in and inverter shuts down. So sub-db without supply. I fail to see how the changeover in that location, with anti-islanding enabled, allows for the sub-db to be fed with the grid down? Wouldnt this be the case for a grid tied non hybrid inverter? A hybrid inverter is allowed to island itself?

Hey everyone, I have started the long process of reading through the relevant regulations for a grid tie (Hybrid and non-hybrid) setup based on the COCT regulations, but have some questions which i'm hoping someone can help with. 1. All inverters for new installations must be compliant to the new sans NRS097-2-1 2017. The list published by COCT has both 2010 and 2017 compliant units, any inverter for new installations (post Dec 2018) would require NRS097-2-1 2017 certification? Otherwise it would be rejected by COCT? Anyone know how hard it would be to have additional units certified by COCT? So even if its 2010 version compliant, you would not be able to register it on a new application? 2. Grid tied hybrid needs to be connected via a changeover switch, suitably rated. A specific changeover switch with break before make is required. Whether automatic or manual. This would imply that there will always be a slight dip during the changeover? Minimum requirement of 20ms. Do you know of a switch which actually satisfies all the requirements? 3. Grid tie non hybrid No transfer switch required? but unit must shut off during loss of grid, i.e. shouldnt be able to island itself? Addition of batteries makes it Grid tie hybrid and requirements of 2 above takes over? 4. What is a suitably rated reverse power flow blocking relay? In the case of running a grid-tie with a prepaid meter, there is a requirement of reverse power flow blocking? What would a suitable blocking relay be? Or is this a function built into the 2017 compliant inverter? 5. NERSA Approval While COCT state they are not requiring approval for less than 1MVA from NERSA, it still makes provision for incase NERSA does make this a requirement in the future. How likely would this be? 6. Off grid setups Does not require COCT approval, but they need to be informed? and a COC to proof electrically separate from grid connection. Lastly, has anyone successfully had a grid tie SSEG approved by COCT? What are the approximate timelines / response time to expect from the city? Thanks in advance for help!