Fundamentals Of Electricity
Principles of Electricity, Theory , Calculations
235 topics in this forum
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Howzit guys so I'm in the process to go completely off grid soon now my question is earthing related. does the N/E Still need to be Bonded together if there is an Earth rod installed? and if so if it has to be bonded together still the earth rod? does it need to be connected to the common earth bus bar as well? the idea is to not use Grid Ever again (Eskom Comes and disconnects the line going to my house ) just solar/generator have way too many problems with grid to either die for a few days or to just supply 80 - 110v >.>
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Good day Let me start off by saying I have a workaround for this issue, but surely it must be a glitch? Not that I am at all qualified in the field of PV, so my comments and deductions might be silly to the experts on this forum. In my limited technical understanding the setup of my solar system is as follows. 20x455w panels 2x5kw Deye inverters 5x5kw Greenrich batteries Setup to feed house 100% at all times - so nothing in the house excluded from getting electricity off the inverters. Only when battery and PV can't supply demand if would use Eskom My system is big enough to take me off grid about 85% of the time, which means my batteries are fully charged through the…
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Hi everyone I'm currently in the process of going off grid. I have a few concerns about the earthing and the earth/neutral bond. My panels are earthed directly to a copper earth rod in the ground. 1) Can I still use Eskom's earthing rod going into my DB as this earth is still the best you will get? If not, what must I do? Currently all my ac earths are connected to earth rod in main DB. 2)Can I feed a 6mm wire from main DB earth rod to my inverter? 3) Where and how will I do my permanent earth/neutral bond once the prepaid meter is removed and fuses pulled from mini sub? Oh! Please try and explain in away that a stupid diy guy lime myself can understand.
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Good afternoon. I just bought this Lumo 2.5kW UPS that I was recommended. I wanted to connect it to my DB board but I am wondering if I need to earth the metal case of the UPS when I connect it? Please could some one explain if i need to or not. Thank you!
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I know this sounds stupid but how does any normal house not draw more than 60A at times? I've worked out that in my new home if I run my oven, both geysers and my two ACs together that already 65A. I know this won't happen often but that's just 5 items. That's not everything else that just runs all the time. If I install a 16KW inverter will it allow to draw max between batteries and Eskom?
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I know the reg says AC and DC may not be mixed. Can I route from a DC db through an AC db and then into trunking. The DC wires will be inside a conduit/Sprague pipe. The DC and AC db's are directly next to each other. Thank you
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Excuse me if my terminology is off, I don't have much knowledge about electrical work. Almost 3 years ago I purchased a property which was sectionalised by the developer I bought it from. It is one erf sectionalised into two sections each with it's own home. My section holds the original home and the second section holds a newly developed house. After I had been staying there for a few months the developer completed and sold the second section. They applied for the electricity connection with Eskom but apparently it takes a while so they asked to connect the next door house to the main distribution board located in my house by laying some pipes through the roof …
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Good day All Last night I read the "wiring-unlimited" e-book shared on this forum. Wow! Excellent read. I would, however, like to ask for some clarification. On Page 49 they talk about the different types of distribution networks namely, TN-S, TN-C, TN-C-S, TT and IT. (Where-from the letters?) In any case, what kind of network does South Africa use or does it depend? I, erroneously, always assumed the three wires on overhead transmission lines were Earth, Neutral en Live. I assume they were actually Live Phase1, -2, and -3 and that the Neutral and Earth only come into "being" at the property? What network does my house have if, as far as I can tell, a single,…
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Broken neutral conditions on low voltage 3-phase 4-wire networks present a challenge not just in terms of appliance failures but more importantly exposes the possibility of life-threatening contact incidents. The Earth Leakage Circuit Breaker (ELCB), required under South Africa law, is purposely designed and installed in all household distribution boxes to mitigate for earth fault conditions associated with these appliance failures and possible contact incidents. Due to limitations in the ELCB design, the unit fails to operate under broken neutral conditions and thus renders the system dangerous and unsafe. A new bespoke Broken Neutral Safety Device has been developed to …
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Hello I have built a data acquisition system for my Mecer solar/grid inverter. Everything is working and I am getting data into my repository but I don't really know what I'm looking at as my background is coding, not electricity. Could someone please explain what these figures are that I'm getting back from the system? Some of them are self explanatory but I have included all the data types returned for completeness if someone else comes across this post looking for the same information. Here is an example of a reading coming in every minute: AC Active Power: 0161 AC Output Apparent Power: 0162 AC Output Frequency: 49.9 AC Output Voltage: 232.0 Battery…
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Just wanted to quickly double check this. When earthing my solar rails / panels on the roof, can I run a 4mm solid core copper wire from each rail and then connect that into the rooftop junction box. This junction box on the roof takes the AC power from the roof and runs it into the DB board (via it's own isolator of course)
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I have a sub board in the studio, it keeps tripping (does not stay up) . When i turn the main boards breaker to the sub board Off in the house (main board) the sub board stay up. When i turn it back on in the house the sub board trips. All breakers at the sub board are off. IS this a faulty earth leakage on the sub board?
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Hi all, I have quite a strange problem. My house is 100% off grid with no Eskom connection. 8kW Sunsynk inverter, 4 x UP5000 Pylontech batteries and 12 x 550W panels. Often when it starts to rain softly the earth leakage on the DB trips. No other CB trip and no error codes on the inverter. I can switch off all the CBs but the Earth Leakage can't be switched on. After about 10 mins I can switch on the EL, and the problem disappears, even if it carries on raining. Funny thing is it happens at the same time with my neighbour, with a similar installation. Any ideas would be appreciated. Thanks
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From high school science I recall that W = VA. (power = current * voltage) So why is the output of my old UPS rated at 3200 VA or 2000 W?
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I was scanning through solar assistant this morning and saw quite a serious grid frequency deviation yesterday at 15h45 on my system in Cpt. This is a quote from Eskom quality of supply document. "Any power with a frequency of as little as 1% above or below the standard 50hz risks damaging equipment and infrastructure if it persists. Small frequency deviations (i.e. -0.5 Hz on a 50 hz network) will result in automatic loadshedding or other control actions to restore system frequency." That frequency spike was 3.4% below the norm my inverter disconnected from grid for that split second.
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As per usual I'm here to gather some information and thoughts please? After a heavy lightning storm at midnight and several direct strikes in my neighbourhood, my batteries went from 67% to 0% instantly and no led's on - no flashing led's nothing. Inverter reported a F56 dc volt low fault. Installer tested next day and sent both batteries and inverter off - apparently these were all damaged. What I don't understand though is that my db didn't trip - the 'eskom' db - I'm still grid tied. Surely if it was a 'near strike' causing a spike the mains would have tripped? How is my inverter and batteries fried but nothing else damaged or tripped? It was definit…
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Good morning. I have a 5kw Kodak inverter with 12 solar panels 6p2s. The 2 sets are on different parts of the roof. one set of 6 panels is north facing on a tiled roof, second set is west facing on a corrugated metal roof. The reason for having 6 panels facing west is I stay in Cape Town and we have sun until very late in the summer. During summer months we hardly use eskom power. Both sets have individual cables running into the house and have their own breakers on each cable. The set that is on the metallic roof trips the earth leakage when it rains or when we have a lot of moisture in the air. I checked and cant find any place where the wiring i…
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The electrician set up the board in the garage, pool, cottage each with their own EL at their respective boards/boxes without being on any EL on the main board. Main board has EL, but only for the breakers in that board. Is this up to the SANS standards? Curious because if someone hit a buried cable with a spade or whatever then it would only trip on overload.
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Yesterday the street whatsapp group lit up with complaints about very low incoming grid voltage. Like > 190 V low. People were saying that their lights wouldn't work properly, that anything that heated via an element was taking longer. More generally they were worried about damage to their appliances. City Power actually reacted quite quickly and went to inspect the substation feeding our street. They said (and I'm quoting 2nd hand here) that it was only the even numbered properties affected, and that the problem was a bent feeder cable. I wasn't sure about the bit about the bent cable, but the voltage came up to about 215V. Until later that evening when…
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Hi I wonder if anyone can assist , a friend of mines solar system is tripping his earth leakage when the battery discharges to 30% and changes overs to Eskom grid . Could it be a faulty earth leakage , anyone experience this before ? Thank you .
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Good day First off I am not an installer, nor competent on solar in any form or shape - so please excuse any nonsensical remarks or questions. So the background as follows: I have 2 x 5kw Deye inverters, setup as slave and master Both were set before to draw 10W from grid at all times This worked out to be around 30 w of continuous usage if the need for higher consumption from grid was not there The master got damaged and replaced and since then: With the settings as before on 10W for both machines it now continuously draws around 300W, when no Eskom load is needed I have changed this to 0W, 30W, 50W - it mak…
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Hi members, i am in need of some help on a 380v CNC Router, where it goes completely haywire with Grid 380Volt, sometimes spiking to 395Volt. Municipality cannot seem to get it right. the CNC runs fine, when running under half speed. i managed to check the units’ internal transformer and found that it outputs around 241Volt, to the electronics side of the CNC. My question is: wil an Inverter fix this issue, or would i need a Power Transformer/stabiliser, to keep outgoing power stable. TIA
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Hi there. I'm trying to find a good explanation to explain why the installation that i have to research has a TN-S earthing system. I conducted several measurements, and they yielded a Zloop of 58 ohms for the L-PE measurement, 60 ohms for the L-N measurement, and 155 ohms for the L-L measurement. My professor mentioned that this already indicates it is a TN system. Why? To specifically indicate that it is a TN-S earthing system, can you simply demonstrate by stating that from the star point of the transformer, the PE and N have different sections? If there is more information needed to help me, let me know. Thank you in advance.https://ibb.co/R4bFWrH
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Good day, all Hope all can help.. Q(A): I connected my inverter to the main isolator and I have a RCD/earth-leakage on the Load side of the inverter. Do you connect the Inverter to your Main breaker to an RCD/earth-leakage or isolators ? Q(B): So do you bond your earth to the neutral permanently (Before the Load RCD/earth-leakage) or with a Relay/contractor? PS: I know there is lots of post on this. Sorry for the double questions. I was told by my elect that going to the do coc's, I must bond my neutral to earth permanently before the RDC/earth-leakage on the load side as there is a floating neutral, and not use the relay as it doesn't wor…
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