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I'm all official!


Elbow

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Yay.  All official!

Thank you to @Rautenk, @Mike@Carl, @Jaco de Jongh, and tons of advice from the ou manne of the forum and lots of others besides.

What an interesting project - I learned a lot in the process and so far not a single shock!

On a day when we face Stage 6 shedding I feel like very clever to have  this system in the house!

Thanks,
@Elbow / Steve

 

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59 minutes ago, Wilfred said:

Congratulations, I guess the process will speed up for all the other applications now that Eskom is into the deep end. Not that it is enough to safe them.

Well it took me a long time to get through all the process on my side - draw the diagrams and get the signoff etc - CoCT was reasonably prompt with their side.

I wonder really if they are able to properly review all the information provided - but I did my best with @Rautenk to build a safe and compliant system.

 

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I got my permission letter to install yesterday. I'm decommissioning it next month because I'm moving. It took 6.5 months to get the permission letter... when it is that slow, and there is load shedding... you kinda have to accept people will go the route of "forgiveness is easier than permission" 🙂

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40 minutes ago, plonkster said:

I got my permission letter to install yesterday. I'm decommissioning it next month because I'm moving. It took 6.5 months to get the permission letter... when it is that slow, and there is load shedding... you kinda have to accept people will go the route of "forgiveness is easier than permission" 🙂

Jeeze...

Back to square one then...

Hope your new place has a nice large north facing roof at just the right angle 🙂

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5 minutes ago, The Bulldog said:

Hope your new place has a nice large north facing roof at just the right angle 🙂

It has a North facing roof. My wife likes the house for other reasons (of course), but when I got there I first looked for a North facing roof (and noted the presence of a shadow-throwing chimney and the location of the pool heating mats... out of the way by the looks of it). Then I went hunting for the distribution board and noted that it apparently has extra space in it (which is remarkable for 1970s houses in Heldervue). Might have happened when the AirBnBs in the back were added a few years ago. Finally, I decided the inverter and batteries goes in the laundry room this time... and bought a good secondhand server case for that purpose. Mean while the wife is buying things to get the AirBnBs up and running... so now there is no space for my car in the garage 🙂

I hate moving, but there remains an element of excitement to it!

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13 hours ago, Ironman said:

Hey @Elbow

...we are on this forum for details details details, not mutual back slapping. Please tell us a bit about your system, the diagrams and documentation needed, and the process. Others want to learn and follow the same path. 
... and congrats.

 

Hi @Ironman,

You will find various photos etc if you look back through my posts.  I've been a pain on Powerforum I'm sure but the ou manne and others have been fantastic with advice and referring me to good guys to help me - most of whom are on this forum.

My system has a "Renesola Replus" hybrid inverter.  These were being cleared out a few years ago at a great price.  Its a Voltronic Infinisolar OEM.  It is on the CoCT magic list of approved devices though it does not meet the latest standard so I needed to get my approval complete before the end of 2019.

Its rated 3kVA but that really only becomes a limitation when the power is out.  When the power is present the inverter really connects the grid and essentials together and then the DC/AC inverter feeds both.  Practically that means that even on the essentials side you can exceed 3kVA.  (Obviously if the grid disappears in that state the inverter will trip so its to be avoided).

I have 9 Canadian Solar 350W panels - I could probably have used 10 but my inverter maximum voltage is 500v and I didn't want to take a chance. So 9 means 3150kW.  COCT rules would have allowed me 3500. In practice I think 10 of these would have been fine.

I have 2 2.4kWh Pylontech US2000B batteries.  I used 80A fuses in both + and - and also fitted a Victron battery monitor.  I probably didn't need a battery monitor since the batteries are smart but its handy at a glance to see the charge state etc.

My inverter has a "grid" connection and an "essentials" connection.  The essentials goes to a sub-board and all my lights, my computer dedicated circuit and some plugs around the house are connected to that.  On the grid side are the high load stuff.

I elected not to feed in to the grid.  So to get that right I fitted a Carlo Gavazzi ET112 meter and a modbus card in the inverter.  The inverter reads the nett power flow from the meter and uses that to try to balance what it feeds in so that it doesn't feed back into the grid.  After buying the ET112 I discovered it was not compatible with my inverter's modbus card - I'm stubborn and a programmer so I wrote a program that runs on a Raspberry Pi and converts the format so that the inverter is happy.

Paperwork wise in Cape Town: It starts with a form and a basic diagram of what you intend to do.  You then get a permission to install letter (I did have to hassle them to get it).

You then do the install, and you may "test".

Once done you will need to have a COC for the electrical work, and there are requirements to be able to isolate, to mark main switches, and etc.  In that process I had to improve my ground for the house.  We also established that my supply from the council is out of spec - heavy load in the house and the voltage at the point of connection sags to something like 195V.  Council came and stuck a meter on the supply and didn't do anything to load it down and shrugged and said its OK and that was the end of that.

You also need a Professional Engineer to sign off that the required automatic isolation works properly - the requirement that the inverter disconnects from the grid if the grid goes off.  He also checks grounding, isolation points, labelling and etc.  @Rautenk did that testing for me - with careful testing which is a bit tricky in the case of a hybrid.

Then you need to do a "single line diagram" which is a sort of circuit diagram of the house electrics.  Karel gave me an example and pointed me at something called profiCAD and I did the diagram.  Took some time but was quite fun.

Lastly, you sign a new supply contract and send all this stuff off the the council who I suppose study it carefully (?) and issue the permission to commission the system.  And you are all official.  Whether that's a good thing remains to be seen!

I did discover that my inverter doesn't ground neutral when disconnected from the grid and supplying from solar or batteries.  So in that case neutral floats at 115 volts or so relative to ground. We've had lots of disussions here about that, especially because my inverter uses a switching inverter and not a transformer creating a question about whether its OK to connect the output neutral to ground.  But mine, at least, seems perfectly happy.  Apparently the inverter is approved, but I didn't think that was safe so I fitted a contactor that links neutral and ground if the grid drops out.

In June I got 315kWh from the panels - so about R800 worth at the higher Cape Town rate.  425kWh in October - R1100 maybe?

 In the summer I don't have enough daytime usage to use up the available energy, and I don't have enough batteries to save it all for overnight - so sometime I'll buy another Pylontech.

On a sunny day with lots of demand in the house I saw as much as 22.6kWh from the panels (October 25th).

I guess I spend R65k and of course many hours.  It was a fun project so I'll pay myself R0.  So on that basis I guess it pays itself off after 6 years.

 



 

 

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50 minutes ago, Elbow said:

You will find various photos etc if you look back through my posts.  I've been a pain on Powerforum I'm sure but the ou manne and others have been fantastic with advice and referring me to good guys to help me - most of whom are on this forum.

Yeah, I was thinking to myself that criticism was a bit much. Well, it was probably not meant that way but it came across that way. For me this thread about how long it takes people to actually get the paper work done... was immensely informative. As I said... I too got my permission after 6.5 months, just in time for not needing it anymore.

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