Jaws

I haven't read your tread or have any idea where that box is connected or installed. But last time I check you are not allowed to bond neutral and earth after the point of control on a TN-C-S earthing system.

Wow how did I miss that, my brain was reading 200 kWp. 200 W is hardly sufficent to charge a modern cellphone

I dont know which regualtions COCT is going to apply but I had a quick look at the latest SANS regulations. WIth Cape town being in an area with less 6 flashes/km2/year you can leave the panels floating. Not that I would ever advice it, adding the bonding is such small price for peace of mind. Local regs only refers to 4mm2 for mechincal strenght. IEC 60364-7 specifies 6mm2 minimium for LPS In Switserland 10 mm2 is set a requirement for LPS - so I guess that where someone picked that up from.

Interesting how would that compare to something like this : https://www.builders.co.za/Electrical/Inverters-%26-Solar-Energy/Inverters/Ellies-Power-Inverter-DC-1200w-2000va-24v/p/000000000000395576?gclid=Cj0KCQiAurjgBRCqARIsAD09sg8WCUdL6xGUI7G16kGBjjOmoNQIBROXaxFVjoLrRNDzB6FbOhURlYwaAlytEALw_wcB R6500 for 1200w/2000kva modified sine inverter which is perfect for keeping the WIFI router, TV and a light or two on.

Hi TTT Like I said the Victron kit is very good, and its what I recommended to a contact in Mozambique about 9 years ago in a very remote location. The equipment was purchased and installed badly by themselfs leading to lots of issues. I send them an Axpert, which worked for them as everything just connected to one box (solar panels, batteries and output) whereas with the Victron equipment there was a seperate MPPT, Inverter and battery charger. Am I saying the Axpert is better than the Victron , no not at all. But at 1/3 the price of the Victron kit the Axpert didnt do halve bad either.

Just my useless 5c on the geysers. If you have access to Eskom you will not be saving money by installing gas geysers. Gas geysers works well in remote locations or as a backup. Also electrical geysers can be used to dump excess solar energy into during the day

You will get different responses as people have different experiences. It’s like asking a car forum which car is the best, or the 4x4 community which 4x4 to buy even cellphone brands will stir up emotions. I have been burnt badly with Victron which in my opinion is way overpriced for what you actually get. If you have the money to blow be my guest, they have good equipment but also not the be all. Ill never buy a R30k Iphone X when a R2.4 k Xiaomi does what I need, but the next guy will feel that its Apple or nothing. Voltronic (Axpert , Infinisolar) offer an excellent value proportion and I have installed a few for friends and family and they have all been running for the last 4 years without a single problem. My new favourite is Goodwe, and Pylontec batteries. From what I can see you don’t require a 3 phase system and the fact that you currently do have 3 phase could complicate matters and add unnecessary expenses to your system in the future. For 13 kW or less single phase is the way to go.

Reason Im asking is because Im a registered PR. Eng. But being a registered Pr Eng doesnt mean you can now willy nilly go and sign off any designs. If you look on the ECSA website you will find the Code of Coduct which states in section 3.1 Competency: (b) A registered person may only undertake work which their education, training and experience have rendered them competent to perform and is withing the category of their registration. My experience lays withing the electrical designs for coal fired power generation, water treatment plants, mining and mineral processing. Bascially sectors that will tie you into working for big mulitnational firms. Im busy self studying battery, inverter and solar systems on the side as somehting that I would be able to consult on in my private capacity.

I wonder if ECSA has seen an influx of PR Eng applications since the requirement for Engineers sign-off ?

Further down in the SANS the highlighted bits just confirms everything we have been saying, nice to know with logical reason one can reach the same conclusions as the nice people compiling the IEC standards 712.433.1.101.3 PV sub-array overload protection The rated current or current setting (In) of overload protective devices for PV sub-arrays shall be determined with the following formulae: In > 1,25 × ISC S-ARRAY and In ≤ 2,4 × ISC S-ARRAY. The 1,25 multiplier used here instead of the 1,5 multiplier used for strings is to allow designer flexibility. A multiplier of 1,25 should not be used in areas where heightened irradiance occurs frequently as this would be likely to cause nuisance overload protective device operation. NOTE In case of specific constraints such as side by side mounting of equipment used simultaneously at nominal current and/or high ambient temperature, the choice of current rating of the protective device could be impacted. 712.433.1.101.4 PV array overload protection PV array cable overload protection is only required for PV installations connected to batteries or where other sources of current may feed into the PV array under fault conditions. The rated current (In) of PV array overload protective devices shall be rated as follows: In > 1,25 × ISC S-ARRAY and In ≤ 2,4 × ISC ARRAY The PV array overload protective devices are commonly installed between the battery or batteries and the charge controller as close as possible to the battery or batteries. If these devices are appropriately rated, they provide protection to both the charge controller and the PV array cable, and consequently no further PV array cable overload protection between the PV array and the charge controller is necessary.The 1,25 multiplier used here instead of the 1,5 multiplier used for strings is to allow designer flexibility. A multiplier of 1,25 should not be used in areas where heightened irradiance occurs frequently as this would be likely to cause nuisance overload operation.

I quickly checked SANS SANS 60364-7-712 ( This is totally out of my field Im here to learn) And on page 29: 712.430.3.103 Requirement for string overcurrent protection String overcurrent protection shall be used if: ((Ns –1) × ISC_MAX ) > IMOD_MAX_OCPR where: Ns is the total number of parallel connected strings protected by the nearest overcurrent protective device. When circuit-breakers with overcurrent protection elements are used, they may also provide the disconnecting means required in 712.536.2.101 to 712.536.2.103. Which basically says that if you have a single string ie Ns = 1 then 1-1 = 0 > Imod_MAX_OCPR you dont not require overcurrent protection. Now my poor brain can relax as up to now having fuses on a single array made no sense to me ***** PERSONALLY I WILL ALWAYS ADVOCATE INSTALLATING FUSES EVEN ON A SINGLE ARRAY****** but strickly speaking I cannot see why a COC can not be issued if you dont have fuses on a single array. - This is why I love the internet other peoples questions forced me to do a bit a digging and learning a bit along the way -

Thank you I will watch it tonight

Thank you for the response Jaco. 1. Something in the Inverter happens and the PV+ touches the 220 VAC. 2. A trunking cover damaging the insulation of the PV + as well as the insulation 220 V live wire causing them to short out. 4. Or a clever electrician thinks the Red and Black PV wires should be connected to 220 VAC Ok from the above scenarios in a single string setup the fuses are actually there to protect the PV panel from other sources of energy as its own production of energy is not sufficient to cause any damage. 3.While producing 4kw the insulation on the PV wires breaks down due to UV damage and touches the normal earth wire. I need to think about this a bit more but the first thing in my mind is that if the + or - wire of a PV string comes in contact with earth nothing should happen as in the case of IT earth system - Even if I touch it I should not get an electric shock as I’m not completing a circuit for current to flow. Hi Chris-R Im not advocating not to use fuses at all. The question was posed how to size solar PV fuses. I had a quick look at SANS/IEC 60269-6 and they states 1.35x In. My thinking was for a single string PV array as the only source of energy the fuses will not really add much in the form of protection. They need to be there I totally agree I was just trying to understand why they are there and not they are there "vir sommer maar net" Thanks Coulomb - Yes that’s why I was always referring to single string arrays - when you have parallel strings the mode of protection actually becomes easier to achieve with the higher fault levels contributed by the other strings.

found an old post with some pics https://powerforum.co.za/topic/863-running-out-of-db-space/?tab=comments#comment-14504

Hi Chris Im coming from a totally different background , and joined the forum to get a better understanding of solar systems and the protection thereof. Due to PV panels having a Isc (short circuit current rating) only slightly higher than the In (nominal current rating) in a single string scenario I don’t see how the fuse will blow. Maximum current flow is during a short circuit event and then with the resultant Isc being so low compared to grid or battery supply systems the fuse in theory will never blow. In my mind short circuiting a solar panel won’t blow up anything, unlike other sources of generation like generator of batteries with high Isc . So why then have fuses on single string PV panels if it’s practically impossible to a protection device that will be able to discriminate between In and Isc ?

Chris is spot on with his advice. Just to state the obvious but is recommended that both the positive and negative conductors must be fused. Nice guide : http://www.cooperindustries.com/content/dam/public/bussmann/Electrical/Resources/technical-literature/bus-ele-an-10191-pv-app-guide.pdf You wount find a better fuse to use in your setup than the current ones you have. The next size down after the 15 A is a 4 A. http://www.cooperindustries.com/content/dam/public/bussmann/Electrical/Resources/product-datasheets-b/bus-ele-ds-1172-14x65mm-pv-fuses.pdf There is a time current curve on that datasheet as well . If you look at it you will see that with only one string a short circuit will not blow the 15 A fuse . On the TCC the 15 A line never crosses 8.7 A. But you have strings in parallel, and all the other parallel string with contribute to the fault current. Let assume 4 parallel strings 8.7 x 4 = 35 A will blow that 15 A fuse after about 15 seconds. But its even worse as the Isc rating is for perfect conditions, so a short circuit in the early mornings or afternoons or even in cloudy weather and the fuse will take a longer time to blow. So much for fast blow

I would rip out the box on the left and that truncking . Then get a nice big surface mount DB with at least two rows. Moun the new DB over the old flush mount DB. And a new Earth leakage . The top row will be an double pole overload / isolator, then earth leakage then the circuit breaker for the loads not connected to the inverter and the grid feed to the inverter. Second row will start with a change over switch then another earth leakge and then all the circuit breakers for the loads on the inverter.

My experience is a bit different. I have done a few CCTV installs with LCD screens, and after a few years they all have some burn in. I even have the Waze speed circle burned into my Samsung S5 OLED screen from when i was driving 3 hours a day. Just for interest both "LCD" and "LED" screen uses LCD panels for the pixels, when flatscreens came out the LCD panel was backlit by a flurenct tube, this was later changed to LCD panels with LED backlights that uses less power as you stated. True LED screens are now called OLED , where each pixel is an LED. But most screens uses pixel shifitng to prevent burn-in . I have a 10 year old plasma with now burn-in at all.

I’m pretty sure you will be able to sort this out by yourself. It’s not rocket science. let me know if you want to borrow an energy meter for a week or two

That isolator is perfectly rated for nightime use.

They are not designed to save a battery they are utilized so save all your other battteries. In other words they tell you that you have a bad apple in your basket so that you can remove it before it spoils all the other apples as well.

Please pm Me your contact details

You can download the ACDC price list from their website Sent from my iPhone using Tapatalk

I had a similar problem, took off the existing DB cover and installed a surface mount DB over it Sent from my iPhone using Tapatalk

Should have said grid tie inverters will not turn on if not connected to a grid supply that is within the specified values, and with turn on I mean take the solar Input and inverted it into AC power Sent from my iPhone using Tapatalk