Corné

Good day Everyone
Always make sure the + is connected to the + unless the + must be connected to the -. Also understand that the - must be connected to the + and sometimes to the -.*
Kind Regards,

Corné

*The above is intended as a joke. Please seek the assistance of a qualified professional.
Discussion-Paper-Correct-Wiring-of-Double-Pole-DC-Breakers-LVL2-131210-v2.pdf

Good day Everyone
Always make sure the + is connected to the + unless the + must be connected to the -. Also understand that the - must be connected to the + and sometimes to the -.*
Kind Regards,

Corné

*The above is intended as a joke. Please seek the assistance of a qualified professional.
Discussion-Paper-Correct-Wiring-of-Double-Pole-DC-Breakers-LVL2-131210-v2.pdf

I LOVE this video:
 

Good day Everyone
Not exactly light reading but some of you may have a lot of time on hand. Why not read up on something that may interest you. The first link is the press release and the second the excel file with the url links to the e-books.
1) https://group.springernature.com/fr/group/media/press-releases/freely-accessible-textbook-initiative-for-educators-and-students/17858180
2) https://resource-cms.springernature.com/springer-cms/rest/v1/content/17858272/data/v4
Kind regards,

Corné

Yes I have one, I have an Axpert and UFO setup, never had issues other than the Axpert switch over is a little slow but all you get is the lights flicker when it does. But that’s nothing to do with the battery.

Thanks a lot, the Python books are great and just what I've been after.. 

Good day Everyone
Not exactly light reading but some of you may have a lot of time on hand. Why not read up on something that may interest you. The first link is the press release and the second the excel file with the url links to the e-books.
1) https://group.springernature.com/fr/group/media/press-releases/freely-accessible-textbook-initiative-for-educators-and-students/17858180
2) https://resource-cms.springernature.com/springer-cms/rest/v1/content/17858272/data/v4
Kind regards,

Corné

Good day Everyone
A test-report on batteries for what it is worth.
https://www.solarquotes.com.au/blog/battery-test-7th-report/
 
Kind Regards,

Corné

Good day Everyone
A test-report on batteries for what it is worth.
https://www.solarquotes.com.au/blog/battery-test-7th-report/
 
Kind Regards,

Corné

How much? One hour of his time most likely. So no less than R300. In my case I paid 6.2k for the CoC and got the DB rewired for free :-P

We have 8 panels in one string. I've found a lot of earthing info on this site, but can't find a specific answer to this question:
Does one really need to earth each individual panel, or is it OK to earth just one and have the mounting structure effectively earth the rest (aluminium / Renusol rails), or maybe earth even second or third one (in which case you may as well just do each one).
 
Many thanks - for future answer to this and also all the other good info you guys have posted, this is one of the best sites I've found in ages and I find myself checking "new posts" every time I have a free minute

I have to add, for clarity, just because these units don't have the double-relay islanding setup, it does not mean they don't island properly. All Victron inverters have LOM detection (loss of mains), and isolate themselves from the grid. The older multiplus however had only one relay, and the regulations (not in all countries, but in many) require two. The regulations also require belt-and-suspender setups, the two relays are controlled by two separate control units that also monitor each other, ie it implements redundancy.

That was mostly for cost reasons. The steel case is still a pretty decent case, but it is significantly cheaper to manufacture. When the MP-II was introduced there was also a clear difference in price, while the old Multiplus 3kVA always sold around the 20k mark, the MP-II came in around 13.5k at the time... and even now is still below the former price of the aluminium one despite major slippage of the exchange rate.
Not really. It is basically the same design, and both the older Multiplus and the newer Multiplus-II have exactly the same capabilities (except for the built-in anti-islanding stuff of course). The differences are that the older Multiplus had two toroids -- one on either side -- while the newer MP-II has a larger single toroid in the middle. This makes the MP-II's no-load consumption much lower. Other than that, there is no difference between the two. The steel-cased version is merely made from more affordable materials.
Moving on then. Let me first point out the main difference. In the pictures above, you will see the MP-II models have two switches in series, while the Multiplus has just one. That's the built-in anti-islanding I already mentioned. Regulations require that you must have two. So that's the first main difference.
There were a total of 9 hardware revisions (maybe more by the time you read this), but there's basically just two main ones, which can be seen in the two left-most pictures. The one had AC-out-2 wired directly to the input side (the picture in the middle). There was no relay to disconnect it, and the only reason to use AC-out-2 is that you could put your non-essential loads on it and have ESS/power assist work without a grid meter.
Then there is the current revision, which returns to the way the older Multiplus did it: Ac-out-2 is on the inverter output, with a relay that drops it when the grid fails.

Going to take a stab at this, also under correction from the blue experts. I understand the the multi-plus as more of an off-grid inverter/UPS, while the Multigrid and MultiPlusII are designed to manage a mini-grid in the absence of utility power. I'm guessing the MultiPlusII is the more modern version, complying to more recent standards, having current sensors on the utility AC inputs, to control possible feedback to the utility. In any event the advertising says the MultiplusII combines the functions of the Multigrid and the Multiplus, and it is suited to a variety of setups, whether it's combined with PV inverters or MPPT's, either AC coupling or DC coupling.
I see they changed from an aluminium body to a steel body, which may or may not affect longevity depending on the installation environment.

I will take a stab at this...
PMP482305000 is the multiplus II 48V/3kW/35Amp charger/32 Amp rated transfer switch "1st edition".
PMP482305010 is the multiplus II 48V/3kW/35Amp charger/32 Amp rated transfer switch new revised "2nd edition" 
... I think the differences have more to do with meeting the long list of varying grid codes in Victron's markets than one model/revision being better/worse at their core function as inverter/charger. So from what I can tell for instance the UK grid code has new(er) requirements that the original muliplus likely no longer meet and they had to make actual hardware changes to make the MPii compliant. I think much of this is around the requirements to adequately disconnect when the grid fails (anti-islanding requirements).
I doubt there will be any difference between the hardware revisions as far as "lowering eskom bill" type scenarios. But the multigrid (even the 12/3000) and multiplus ii both appear on the COCT list of approved equipment, the normal multiplus does not - so from a legal grid-tie scenario the multi-grid and multiplus ii will likely be a safer choice than the multiplus.
(looking at the spec sheets there are some smaller "cosmetic" differences like bat/temp sense between the two versions)
As far as the diagrams go.... 1st one has 6 triangles, second one has 5, and third one has 4.... 😉. I say this in jest and is waaayyyy above my knowledge level but am pretty sure the "triangles" will point to how they are setup internally in terms of relays/switches, which should make more sense when you look at what input/output you might want to have connected to which other input/output while the gird is connected and when it's not.
The clever okes will hopefully pop in with corrections and more useful info... 

Hi Everyone
I came across this document explaining tripping curves in a language I could, more or less, understand.
Corné
Understanding Trip Curves.pdf

See my bus-bar solution, with BMV shunt and Fuses.  Uses a Gewiss box (GW44208) and a base-plate split into two sections.

Good morning everyone
I have questions purely for the sake of interest. Lets say the whole municipality is load shed:
1) How is the power switched on and off? Is there like a main MAIN circuit breaker that someone goes and switch on and off?
2) Does someone physically have to go and drive somewhere to throw the switch or is it done electronically/remotely?
3) And lastly, how does the circuit breaker (if such a thing is even used) switch such a large load? Wouldn't it arc leading to "strange" voltages similar to power dips when a kettle or AC is switched on (inrush current?)?
Thank you in advance for entertaining my silly questions?

Good Afternoon

At last a topic I can maybe assist with... South African legislation (Occupational Health and Safety Act, Act 85 of 1993 and Asbestos regulations) makes provision for two types of situations. The one is called "demolition work". Demolition work is where exposure to asbestos is possible but excludes asbestos cement products. If you have asbestos in raw format, used as lagging on steam pipes for example, you will need to get the services of a registered asbestos contractor. Refer to the asbestos demolition work guideline document below.

Asbestos cement products is less dangerous since the asbestos fibers is contained or held onto by the cement. In this instance you do not need the services of a registered asbestos contractor. You only need to follow work procedures that will prevent the creation of dust. For example, no cutting with power tools, especially abrasive cutting methods. No drilling at high speed, slow drilling is fine. No dry scrubbing, wet scrubbing is fine. No high-pressure water washing.

Contrary to popular believe, it is often better (less overall health risk) to retain the asbestos cement roof, for example, as is and keep it well maintained - regularly painted - than to have it removed.

South African legislation is generally pretty strict with regards to asbestos (it has been banned) while it is still used in the USA and Canada for example.

The following article could be of interest.

https://www.timeslive.co.za/news/south-africa/2017-06-20-how-safe-are-gautengs-asbestos-schools/

How old is the building?
Asbestos guidelines.pdf Asbestos-Demolition-Work-Guideline.-2016.pdf Asbestos Regulations.pdf

Good Afternoon

At last a topic I can maybe assist with... South African legislation (Occupational Health and Safety Act, Act 85 of 1993 and Asbestos regulations) makes provision for two types of situations. The one is called "demolition work". Demolition work is where exposure to asbestos is possible but excludes asbestos cement products. If you have asbestos in raw format, used as lagging on steam pipes for example, you will need to get the services of a registered asbestos contractor. Refer to the asbestos demolition work guideline document below.

Asbestos cement products is less dangerous since the asbestos fibers is contained or held onto by the cement. In this instance you do not need the services of a registered asbestos contractor. You only need to follow work procedures that will prevent the creation of dust. For example, no cutting with power tools, especially abrasive cutting methods. No drilling at high speed, slow drilling is fine. No dry scrubbing, wet scrubbing is fine. No high-pressure water washing.

Contrary to popular believe, it is often better (less overall health risk) to retain the asbestos cement roof, for example, as is and keep it well maintained - regularly painted - than to have it removed.

South African legislation is generally pretty strict with regards to asbestos (it has been banned) while it is still used in the USA and Canada for example.

The following article could be of interest.

https://www.timeslive.co.za/news/south-africa/2017-06-20-how-safe-are-gautengs-asbestos-schools/

How old is the building?
Asbestos guidelines.pdf Asbestos-Demolition-Work-Guideline.-2016.pdf Asbestos Regulations.pdf

Ok. Here is the proof !!  

Pictures or its not real!? 😉

An induction plate is cold to the touch even when it is on. What it does is induce eddy currents in the utensil placed on top of it, causing that to heat. A bit like this cool tool.
It only works with metal containers and better with some than with others. It does not use much less power, but because the heat is generated in the utensil (rather than below it) you avoid the transfer loss. So it comes out slightly ahead of a flat plate element in the efficiency stakes.
I still find that people grossly overestimate the amount of electricity they actually use for cooking. The average household that cooks a pot of vegetables, rice and meat (as is typical in South Africa) three or four times a week will end up using less than  10% of overall use in the month for cooking. If your cooking is around 10% more efficient, that means a saving of 1% on the total bill . If you go with gas instead, it costs about 10% more (assuming my previous estimate of roughly half the efficiency to be accurate). Unless you measure carefully the difference is almost negligible.
How many times have you heard people tell you that gas is so efficient, they've been using a single 9kg bottle of LPG for 6 months now? Well, as we know, energy is neither created nor destroyed, and with 115kWh in that bottle, the electricity bill would have been about the same, and possibly quite a bit less (due to efficiency). But since nobody (or few-bodies) does a before and after test, everyone just marvels at how awesome the gas stove top is 🙂

Thanks all for your replies. @Clint what you are saying makes a lot of sense. What I have perceived as being a delay may have only been the one zone pressurizing as the other one is depressurizing.

@Corné,
I have more or less the setup of what you are looking for.
When my previous pump failed (the splines wore out, so motor is spinning, but pump stood still), i upgraded to a bigger pump - so i can open two circuits simultaneously - and installed one of the red pressure tanks, with a pressure measurement meters with built-in actuator. When pressure builds up to 5 bar, the pump switches off. When is drops to 2.5 bar-ish, the pump switches on. There is some heavy duty 3ph switchgear in the grey box against the wall that has a clear thud when it switches.
So now all i do is manually open and close the 24V valves, as i do not have a Hunter Control unit yet!