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Firstly i do apologize i have no electrical knowledge and would really appreciate your help and guidance. 

I have a 60 Amp breaker in my house and would like to install the Goodwe 4.6Kw Hybrid inverter.

  • If i do this will it be approved by COCT?
  • Cant the electrician just upgrade the breaker to an 80 Amp Breaker?
  • Would you recommend the Goodwe 4.6KW inverter?
  • What is a good price for the Goodwe 4.6KW Hybrid Inverter?

For my battery backup im  looking at adding 3 Pylontech 2.4kwh batteries.

  • Is it best to start of with two 3.5KW batteries or three 2.4KW batteries
  • Can i add 3.5KW batteries to a 2.4KW battery bank later if i want to upgrade?
  • What is a good price for the 2.4KW batteries and or the 3.5KW
  • What is a reasonable lifespan for these batteries

I will also connect 12 x 360W Canadian Solar PolyPERC's. 

  • How many Solar Panels can i connect based on the 4,6 Inverter and the battery bank
  • How does the 360W Canadian Solar PolyPerc panels compare to other makes / sizes taking price and value into consideration
  • What is a good price for Solar Panels?

Taking all the above into account i would like to upgrade the system in 2 years time by adding additional batteries and panels

Your comments will be greatly appreciated. 

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3 hours ago, Lourens78 said:

Cant the electrician just upgrade the breaker to an 80 Amp Breaker?

No, for two reasons.

The breaker is there to protect the cable. Without the breaker, the cable could get hot and set something on fire. If the cable is not rated for 80A, you cannot just upgrade the breaker.

Even if the cable can handle 80A, you have to remember there is usually also a breaker on the other end of the cable, one you don't have easy access to. This one is usually larger than the one on your end, because that adds specificity to the system: The one on your end will trip before the one on that end. If you upgrade it, then you may need to call the municipality each time it trips on the wrong end (plus, they will probably start to look for the reason too).

You have to apply to have the breaker upgraded. CoCT has already indicated they will not upgrade it if your sole reason is that you want to install a larger SSEG.

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9 hours ago, plonkster said:

specificity

Technically this is called "Current Level Discrimination" and is a technique linked to the staging of the Long Time (LT) tripping curves of two serial-connected circuit-breakers. (Quoted from the Schneider Electrical installation guide)

An interesting point is that overload protection of a cable can be implemented either at the source or at the load side but short circuit protection has to be implimented at the source.

@plonksteris spot on.

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10 hours ago, plonkster said:

No, for two reasons.

The breaker is there to protect the cable. Without the breaker, the cable could get hot and set something on fire. If the cable is not rated for 80A, you cannot just upgrade the breaker.

Even if the cable can handle 80A, you have to remember there is usually also a breaker on the other end of the cable, one you don't have easy access to. This one is usually larger than the one on your end, because that adds specificity to the system: The one on your end will trip before the one on that end. If you upgrade it, then you may need to call the municipality each time it trips on the wrong end (plus, they will probably start to look for the reason too).

You have to apply to have the breaker upgraded. CoCT has already indicated they will not upgrade it if your sole reason is that you want to install a larger SSEG.

This makes 100% sense thank you very much.. 

Out of curiosity how do people get it right to install these 5KW inverters if they have 60A breakers? i have not come across any house yet unless it had 3 phase where it has a breaker bigger than 60A.

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9 hours ago, Lourens78 said:

Out of curiosity how do people get it right to install these 5KW inverters if they have 60A breakers? i have not come across any house yet unless it had 3 phase where it has a breaker bigger than 60A.

60A breaker will give you close to 14kw at around 230v.... much more than the 5kw inverter can handle. Your inverter will probably switch off due to overload before you breaker will trip

Edited by stoic
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Thank you for the info so far it is really informative. I will contact the COCT on monday and find out if they will have issues pertaining to the Goodwe 4.6. It does look as if you can get it approved. 

If you have further info on the questions above it will be much appreciated. 

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22 hours ago, Lourens78 said:

Out of curiosity how do people get it right to install these 5KW inverters if they have 60A breakers? i have not come across any house yet unless it had 3 phase where it has a breaker bigger than 60A.

 

13 hours ago, stoic said:

60A breaker will give you close to 14kw at around 230v.... much more than the 5kw inverter can handle. Your inverter will probably switch off due to overload before you breaker will trip

I think he means in he CoCT context of 25% of that 60A breaker. The 25% rule applies to inverters that grid-tie. The 5kw axperts everyone installs is 1) not a hybrid, and 2) not always installed in Cape Town. For a long time CoCT even said outright the Axpert cannot be legally installed. For an equally long time, I personally argued that they don't even comply fully with SANS... but the truth is I simply don't know anymore. Apparently you can install them and declare them off-grid.

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4 hours ago, plonkster said:

I think he means in he CoCT context of 25% of that 60A breaker. The 25% rule applies to inverters that grid-tie. The 5kw axperts everyone installs is 1) not a hybrid, and 2) not always installed in Cape Town. For a long time CoCT even said outright the Axpert cannot be legally installed. For an equally long time, I personally argued that they don't even comply fully with SANS... but the truth is I simply don't know anymore. Apparently you can install them and declare them off-grid

Is the 25% not limited on the feedback side of things?

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48 minutes ago, stoic said:

Is the 25% not limited on the feedback side of things?

Man... I would say let sleeping dogs dogs lie. The official reason for the 25% limit is that they want to limit the "pick up". When an embedded generator trips, whatever it was powering needs to be picked up by the grid. When some anomaly on the grid (low voltage event for example) causes the entire neighbourhood's embedded generators to disconnect, the grid has to pick up all of that. So they are not at all concerned about how much is being fed in, they are concerned about the spike that results of all those feeders go away.

So while one would think you can build a system that generates 10kW, but you carefully control it so no more than 3.5kw goes into the grid... that would not be allowed, because that has a potential pick-up of 10kw... not just 3.5.

Now one would also think that if you put a 5kVA hybrid inverter (eg a Multiplus-II) on the grid, with 3.5kW of PV modules... that inverter can supply the difference from the batteries, so it could potentially push as much as 4kW from the combined DC sources, and therefore the pickup for that combo is in actual fact 4kw (and not just 3.5). But CoCT looks only at the PV modules (the PV module is the generator, not the inverter)... and so you can get it approved if the PV array or the inverter is small enough... disregarding the battery component completely.

🙂

 

Edited by plonkster
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2 hours ago, Pietpower said:

If you have an off-grid system and it trips then there will be no draw from the grid. Is there a situation that could cause multiple off grid inverters to drop the batteries and pv and remain powered on to draw from the grid?

Indeed. If we take the common-as-weeds Axpert systems that switch on low battery, then one could say that Axpert's do "trip". Trip, in this context, is when the system transfers the load back onto the grid. Axperts do transfer their loads back onto the grid, and they do so in a pattern (after dark, or on a rainy day), and this would cause some pick-up. This pickup is however spread over a much longer period and does not contribute to the same kind of event that you'd get witih a grid-tied setup that trips. So I maintain that applying grid-tied limits to such off-grid setups does not make sense, but 1) there are no alternative rules, and 2) the guys who do the sign off follow the rules, they are not allowed to add their interpretation into it.

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2 hours ago, Pietpower said:

How does the 360W Canadian Solar PolyPerc panels compare to other makes / sizes taking price and value into consideration
Canadian solar and JA solar was the two recommended to me.
You need to take the mounting system and roof layout into account when comparing sizes and prices

I must say the people on this forum is genuinely helpful. 

I have a tile roof and is 100% north facing i have about 40sqm i can use of the  (4 x 13 tile roof) 

2 hours ago, Pietpower said:

For me more but smaller panels worked out cheaper

Why did you choose smaller panels and not bigger for the full array or with let's say 15 panels (160w) or will 8 (300w) panels also work, my understanding you can connect up to 19 solar panels to the Goodwe. My thinking is longer term. i.e adding additional panels.

What is the pro's and cons around this decision?

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39 minutes ago, Pietpower said:

This type of load increase has always been part of the city engineers design problems.  Evenings when many use showers and ovens to make food.  The english who all switch on kettles for a cup of tea after sports games (or something like that)

Agreed. I mention it merely for fairness (so people cannot say I did not consider this characteristic). 🙂

 

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On 2020/02/21 at 7:45 PM, Lourens78 said:

Firstly i do apologize i have no electrical knowledge and would really appreciate your help and guidance. 

I have a 60 Amp breaker in my house and would like to install the Goodwe 4.6Kw Hybrid inverter.

  • If i do this will it be approved by COCT?

The 4.6 KW ES is on the list of approved inverters.

  • Cant the electrician just upgrade the breaker to an 80 Amp Breaker?
  • Would you recommend the Goodwe 4.6KW inverter?

Yes. With some caveats.
1) The Victron gear offers greater expansion in the future
2) Goodwe has 4 operation modes which are fairly generalised. By nature I like to fiddle and tweak. That's not always a good thing, because you can foul things up. But if you like tweakability then, again, maybe look at Victron.

  • What is a good price for the Goodwe 4.6KW Hybrid Inverter?

...

Taking all the above into account i would like to upgrade the system in 2 years time by adding additional batteries and panels

Is the idea to go completely off grid? That's expensive. You need enough battery to contend with a period of sustained gloomy weather, enough solar panels to get them charged up in good time, and an inverter that can handle that. Plus probably a generator as a last resort.

use the first two years for learning what your property draws and when, and how long your system can run the essential circuits. Also use the various apps to identify high loads on the property and decide what to do about them. Consider going to gas for cooking and solar or heat pump for water heating as they are two of the biggest loads in your house. 

A point I always make. Get a COC (or amendment to your existing COC) from a competent person and make sure your insurers get a copy and know that you have a solar system. Otherwise if the worst comes to the worst they will send out a loss adjuster who will very quickly notice that there are wiring changes that they weren't told about or is not described on your COC and so you have misdeclared the risk to them and so the policy is voided.

Edited by Bobster
snippage
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  • 2 weeks later...
On 2020/02/24 at 10:50 AM, Bobster said:

Is the idea to go completely off grid? That's expensive. You need enough battery to contend with a period of sustained gloomy weather, enough solar panels to get them charged up in good time, and an inverter that can handle that. Plus probably a generator as a last resort

Agree, off grid is very expensive. I am trying to get as much off the grid as possible. So for now i am busy with adding 12 x 370w Canadian solar Panels and two 3.5kw Pylontech batteries with a Goodwe 4.6 Inverter.  

 

On 2020/02/24 at 10:50 AM, Bobster said:

use the first two years for learning what your property draws and when, and how long your system can run the essential circuits. Also use the various apps to identify high loads on the property and decide what to do about them. 

I think this will be a massive learning for me, either way its not going to be a loss as it will cover all the essentials in my house. 

 

On 2020/02/24 at 10:50 AM, Bobster said:

onsider going to gas for cooking and solar or heat pump for water heating as they are two of the biggest loads in your house. 

Yes, i think this is very important. Use low energy appliances and if not if you can overtime replace them. I started off by replacing electric hob with gas hob, i replaced b class fridges with A++. I replaced my geyser with a solar geyser. 

 

On 2020/02/24 at 10:50 AM, Bobster said:

A point I always make. Get a COC (or amendment to your existing COC) from a competent person and make sure your insurers get a copy and know that you have a solar system. Otherwise if the worst comes to the worst they will send out a loss adjuster who will very quickly notice that there are wiring changes that they weren't told about or is not described on your COC and so you have misdeclared the risk to them and so the policy is voided.

This was the starting point! First find a reputable company that can install and certify your system if they cannot do it and provide you with the necessary certifications when completed then i would not have started. 

 

 

 

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1 minute ago, Lourens78 said:
On 2020/02/24 at 10:50 AM, Bobster said:

A point I always make. Get a COC (or amendment to your existing COC) from a competent person and make sure your insurers get a copy and know that you have a solar system. Otherwise if the worst comes to the worst they will send out a loss adjuster who will very quickly notice that there are wiring changes that they weren't told about or is not described on your COC and so you have misdeclared the risk to them and so the policy is voided.

This was the starting point! First find a reputable company that can install and certify your system if they cannot do it and provide you with the necessary certifications when completed then i would not have started. 

Yes, but I'm saying that you should keep your insurer informed. It shouldn't affect your premium unless you specifically insure some internal components, but it is wise to be in a position where the risk is accurately described. Probably a valid COC signed by a competent person will prevail in the end, but a claim may be held up.
 

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6 minutes ago, Lourens78 said:
On 2020/02/24 at 10:50 AM, Bobster said:

use the first two years for learning what your property draws and when, and how long your system can run the essential circuits. Also use the various apps to identify high loads on the property and decide what to do about them. 

I think this will be a massive learning for me, either way its not going to be a loss as it will cover all the essentials in my house. 

You will get monitoring tools with the Goodwe, and you will very quickly get a good picture of what is happening when. And you will very quickly see the impact of any changes that you make. 

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  • 4 weeks later...

Random Question on the Goodwe 4.6kw ES. It has a dual MPPT rated at 11/11 Amps so basically 11 Amps a string right for a max wattage of 6500W and 580Volts. Does this mean that each string must not exceed 11 Amps?

If so then this basically limits you to connecting the panels in Series, or am I missing something?

 

Regards

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10 hours ago, Jaco de Jongh said:

That is correct. One single string per mppt

Right. It is one of the quirks of the Goodwe that is often missed/forgotten. To get the full wattage out of it, you must push the voltage up, because it's limited to 11A on the PV side, and that's pretty much what most 300W panels make when you put them in really sharp sunlight... 🙂

 

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17 hours ago, Mo_s said:

Random Question on the Goodwe 4.6kw ES. It has a dual MPPT rated at 11/11 Amps so basically 11 Amps a string right for a max wattage of 6500W and 580Volts. Does this mean that each string must not exceed 11 Amps?

If so then this basically limits you to connecting the panels in Series, or am I missing something?

 

Regards

Stupid question:

The maximum DC input votage is 580V and

The minimum Startup voltage is 150V

Is that PER String, or in TOTAL accross both strings. 

I.E, if you have a string of 4 panels (North) delivering 160V (40x4) and another string of 4 Panels (West) delivering 120V (40x3) will those be enough to startup the the inverter or is it to touch and go as it so close to the minimum startup voltage?

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1 hour ago, daniemare said:

Is that PER String,

Yes, per string

1 hour ago, daniemare said:

I.E, if you have a string of 4 panels (North) delivering 160V (40x4) and another string of 4 Panels (West) delivering 120V (40x3) will those be enough to startup the the inverter or is it to touch and go as it so close to the minimum startup voltage?

This is to close for comfort, in this case i would rather put all 7 on one MPPT and add some panels later. 

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