admiral Posted March 28, 2019 Posted March 28, 2019 On 2019/03/11 at 9:42 PM, 2una said: I have a question i've overlooked if someone might set me straight to the answer please Whether it be Victron or Axpect type inverter on a battery only system(UPS), are we allowed to have this hooked up to make use of the "20ms changeover" or must it always be a manual deal with manual changeover switch? I'd also like to know the answer to this - especially in the City of Cape Town. My tactical solution for right now would be a MultiPlus II with some old UPS batteries, just running from grid power to charge the batteries, and then to supply electricity when we have load shedding. Can I use the inverter to automatically switch over to batteries, or must I walk to the board and flip the change-over switch for the essential loads from grid to inverter? It would be mighty stupid if I can't use the inverter to carry on as if nothing is wrong... Quote
The Bulldog Posted March 28, 2019 Posted March 28, 2019 (edited) Just now, admiral said: I'd also like to know the answer to this - especially in the City of Cape Town. My tactical solution for right now would be a MultiPlus II with some old UPS batteries, just running from grid power to charge the batteries, and then to supply electricity when we have load shedding. Can I use the inverter to automatically switch over to batteries, or must I walk to the board and flip the change-over switch for the essential loads from grid to inverter? It would be mighty stupid if I can't use the inverter to carry on as if nothing is wrong... Unfortunately as things stand at the moment COCT specifically refers to and insists on an EXTERNAL change-over switch. Yes - this is mighty stupid but this is what it is. Don't even bother trying to argue the point with them - done that got the T-Shirt and got nowhere. But in your case there is good news: Since you are not connecting PV or any other generation source you have a simple SANS 10142 compliant UPS. This is not SSEG whether on-grid or off-grid so you do not have to apply to COCT for permission. Your system only needs a COC and COCT is not involved. The very moment you connect a PV panel to your battery you have an SSEG and COCT has you in their sights... Edited March 28, 2019 by The Bulldog Quote
admiral Posted March 28, 2019 Posted March 28, 2019 @The Bulldog - so, let me confirm if I understand this correctly... We can put a Multiplus II in the garage, wire it up the batteries, and connect it to the grid to charge those batteries. For now, let's say it will be plugged into a plug socket of sufficient size. We can take the output of the Multiplus II to the db board, and wire it into a change-over switch (break before make of correct specs). This switch has to be "on grid" when the grid is functioning. In case of load shedding the Multiplus II will start generating electricity because it sees its input is dead. We then wander over to the board, and change the switch over to the inverter. Is that about right? Quote
___ Posted March 28, 2019 Posted March 28, 2019 22 minutes ago, admiral said: We then wander over to the board, and change the switch over to the inverter. When you don't have PV modules connected, you don't need to manually throw the switch. You can let the inverter do the switchover (as it is designed to #%$-well operate). You will still put a changeover in the DB for the sole reason that you might want to bypass it occasionally for maintenance or whatever. In UPS mode the Multi already does what CoCT requires: The battery component is only connected after the grid is disconnected. The moment you connect PV modules, then they put you under an extra large magnifying glass. They don't trust that very same inverter anymore and now you need an external changeover switch. The same SANS-10142 that was okay with your inverter until 5 minutes ago now requires an external changeover switch.... cause we just can't trust other people to do this correctly. Fuenkli 1 Quote
Guest Posted March 28, 2019 Posted March 28, 2019 Just get a CoC with the install, mainly for safety and secondly insurance purposes. Quote
admiral Posted March 28, 2019 Posted March 28, 2019 @plonkster - I think I'll start a CoCT specific thread on this. It makes *zero* sense to me as the inverter is just as much grid-tied without PV as with PV... Quote
Guest Posted March 28, 2019 Posted March 28, 2019 12 minutes ago, admiral said: @plonkster - I think I'll start a CoCT specific thread on this. It makes *zero* sense to me as the inverter is just as much grid-tied without PV as with PV... We have a few already. https://powerforum.co.za/topic/2109-is-your-system-legal-capetonians-have-till-28-feb-2019-to-register-their-systems/ Quote
admiral Posted March 28, 2019 Posted March 28, 2019 @The Terrible Triplett - yeah, I meant a thread specifically for doing a UPS installation in CoCT which is a tactical way to get around load shedding. Quote
Guest Posted March 28, 2019 Posted March 28, 2019 1 minute ago, admiral said: @The Terrible Triplett - yeah, I meant a thread specifically for doing a UPS installation in CoCT which is a tactical way to get around load shedding. Old tekkies as UPS installs have been around for yonks as in all good sparkies know exactly what to do with eyes closed, to give you the CoC. With the MP II that you want to install, it even has "papers", so better than most installs. Quote
___ Posted March 28, 2019 Posted March 28, 2019 18 minutes ago, admiral said: - I think I'll start a CoCT specific thread on this. It makes *zero* sense to me as the inverter is just as much grid-tied without PV as with PV... Well, no. Let's be fair. When the inverter is running the ESS assistant, then it is grid-tied. When it doesn't have this assistant installed, it behaves like a UPS. You could of course argue that the inverter has the CAPABILITY (it is a mere software setting), but such an argument would also apply to UPSes (sans PV). In fact, that is how peak-shaving systems installed in areas with TOU tarriffs (time of use) work. They tie a battery with the grid and offset the peak. No PV modules in sight. You could also argue that if I run it without the ESS assistant (what Victron historically called a Hub-2 setup), then technically it complies: The grid is disconnected before the battery component is engaged. But CoCT wants this component to be an external thing for some reason. Lots of people have questioned the sense in all of this. Quote
The Bulldog Posted March 28, 2019 Posted March 28, 2019 9 minutes ago, admiral said: @plonkster - I think I'll start a CoCT specific thread on this. It makes *zero* sense to me as the inverter is just as much grid-tied without PV as with PV... Yes you are quite right - this very fact is right in front of me as my current application uses the Multiplus (not even the NRS-097 one) as UPS and COCT is happy. Yet the very same system I applied for with PV connected to the battery was a no-go. It forced me to add a grid-tie inverter that is on COCT's list for no reason whatsoever (from any form of safety or technical viewpoint anyway). BTW, there was indeed an attempt to make life difficult for the UPS users in a PV installation: The original NRS-097:2017 had a paragraph specifically insisting that any UPS used in PV installation had to be NRS-097 certified. In the current release this has been removed with a note that UPS requirements are specified elsewhere (i.e. SANS). No doubt some clever oke realized that there is no such thing as a NRS-097 certified UPS in existence. This illustrates nicely the "potshot" approach of creating regulations... Quote
admiral Posted March 28, 2019 Posted March 28, 2019 @plonkster I am just happy to hear I can install a Multiplus II in UPS fashion - legally. And then get the SSEG stuff sorted out for adding panels. Nice way to start using some bits and be more resilient. Quote
SilverNodashi Posted March 28, 2019 Posted March 28, 2019 2 hours ago, admiral said: I'd also like to know the answer to this - especially in the City of Cape Town. My tactical solution for right now would be a MultiPlus II with some old UPS batteries, just running from grid power to charge the batteries, and then to supply electricity when we have load shedding. Can I use the inverter to automatically switch over to batteries, or must I walk to the board and flip the change-over switch for the essential loads from grid to inverter? It would be mighty stupid if I can't use the inverter to carry on as if nothing is wrong... I want to clarify something, as I see some confusion. Any inverter with built-in charger has a change-over switch to switch over from primary to secondary source. i.e. from Eskom to Batteries / Solar to batteries / Solar to Eskom / etc. In many cases this happens within 10 ms, so you won't miss the Rugby match when Eskom decides to cut your electricity. It will change over to batteries automatically. The changeover that @The Bulldog and @plonkster refers to is installed additionally in order to make it compliant. This is a manual change over switch which will basically either feed your house from the inverter, or from Eskom (Or a generator if you have another one). This is also handy if your inverter needs repairs, batteries need replacement, etc. Quote
The Bulldog Posted March 28, 2019 Posted March 28, 2019 2 minutes ago, SilverNodashi said: I want to clarify something, as I see some confusion. Any inverter with built-in charger has a change-over switch to switch over from primary to secondary source. i.e. from Eskom to Batteries / Solar to batteries / Solar to Eskom / etc. In many cases this happens within 10 ms, so you won't miss the Rugby match when Eskom decides to cut your electricity. It will change over to batteries automatically. The changeover that @The Bulldog and @plonkster refers to is installed additionally in order to make it compliant. This is a manual change over switch which will basically either feed your house from the inverter, or from Eskom (Or a generator if you have another one). This is also handy if your inverter needs repairs, batteries need replacement, etc. There is a little more to this story - the SSEG requirements document specifies just how this external switch operates with respect to your changeover. Effectively it prevents you from just leaving it in the "inverter" position while you use the internal mechanism of the inverter - regardless of if it is NRS-097 compliant or not. This does not apply if you are using a UPS. I have learned that COCT, for the moment anyway, really applies what they have related to documentation to the single letter and are extremely reluctant to "interpret" or acknowledge equivalence. I sincerely hope this will change to a more enlightened approach soon. Fuenkli 1 Quote
Guest Posted March 28, 2019 Posted March 28, 2019 13 minutes ago, The Bulldog said: I sincerely hope this will change to a more enlightened approach soon. It will. Just be patient. And I would also bet that your setup will be approved. I say this because I believe they are getting it from all sides, internally and externally, and no-one is pulling back. So we just need to be patient, keep the pressure on. As I sit with this problem I sit and wonder what if one was to sue the person and his / her boss personally who forces me to incur more costs, just for it to change, because they wanted to play official and not be a servant of the public, and use their brains. Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.