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UPS Back-up, Also A Complement To FTA / FTA Frequency / Cctv Installation A Complement To Fta And Solar Energy (2) (3) (4)
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Re: Solar Energy, A Complement To FTA by dollarnaira: 11:36am On Dec 03, 2022 |
NiyiOmoIyunade:Well done! |
Re: Solar Energy, A Complement To FTA by NiyiOmoIyunade(m): 11:47am On Dec 03, 2022 |
This image you posted - I am struggling to see the relevance to PV protective earthing. As for the NEC expose on youtube, I am fairly sure responses to youtube comments as the authority for best practice will be dimly regarded by home insurance and the code compliance inspector. If you could reference the actual NEC codes you are referring to as support for your position that would be nice - the ones you have paraphrased here are almost exactly the best practice I have been preaching. The codes are not nice to haves but actually mandatory compliance requirements for a facility to pass inspection and qualify for insurance - try claiming insurance when lightning has damaged your property and you are unable to demonstrate code compliance and watch the claim thrown out. Here in Nigeria we do whatever we like, get lucky because we did not suffer an actual hit and call ourselves experts on doing it right. Please read the things I said and see if you have issue with any particular one then we can discuss that very one in detail - to my mind it appears there is some conflation between connecting the designated earth point and chassis of equipment and frames of exposed outdoor objects to protective earth (Earthing) vs connecting the AC neutrals and DC negatives together or to thesame earth point (Grounding) and sadly these terms are also used loosely and interchangeably. There is a limited number of cases where one may setup his PV protective earth and keep it isolated from the main facility earth and the codes cover these as well - these are more exceptions than the norm. Again, let us leave quoting arcane references to code and pick one actual scenario or problem and we can work out the merits of various approaches strictly based on the risk vs protection trade offs the alternative approaches offer. jonescosmo: 1 Like |
Re: Solar Energy, A Complement To FTA by jonescosmo(m): 12:36pm On Dec 03, 2022 |
NiyiOmoIyunade: I think enough is been said on this topic already let's drop it. At least people have gotten the message in relation to many different scenarios and they can decide exactly what to follow. Electrical Codes are there in the open. People should go scroll through most of them that have covered Earthing or Grounding and deduct their methods accordingly. For me whenever I acquire any electrical gadget I always look at the conformities first before installing them and if there are modifications I need to make to my existing installations, I make them. And then I will compare what changed from the prior conformities. Some people might be stuck in the past with a certain information on their minds without knowing that things have changed a bit from what it used to be. Enough on this topic bros. Except someone asks for recommendations or directions. I bow out. We move, 1 Like |
Re: Solar Energy, A Complement To FTA by contease(m): 12:54pm On Dec 03, 2022 |
NiyiOmoIyunade: Seriously, why are both of you doing this to us, you just drive my brains like "it's convayed in a roller coaster" �. But was a nice read from both of you... I see both of you still have alot to contribute to this particular subject matter, for me, one take home is "Do not connect DC negative to any protective earth at all" and now it's clearer. Why dont we have a space on Twitter and have a real talk on all of these please... I know Niyi still has a lot to pour out... But to be honest Niyi, sometimes your choice of words, I know they are the right vocabs and terminologies, but I really get lost reading your articles and then I have had to call you to get them expressed better in words and this is why I think Twitter space will help all of us understand even much more what you have explained in writting. Mr Niyi, please open one, could be late evenings and I sure will be one of your listeners.... Kudos guys! 1 Like |
Re: Solar Energy, A Complement To FTA by AshipaEk0: 12:57pm On Dec 03, 2022 |
Please where can I walk in physically to buy DC ceiling fans? |
Re: Solar Energy, A Complement To FTA by odimbannamdi(m): 1:00pm On Dec 03, 2022 |
odimbannamdi: Thanks for your contribution, guys. I sincerely appreciate. So, i have opened up the inverter and discovered that one of the 4 output mosfets is burnt. First and second attached pictures show the damaged mosfet. The mosfet is S60N12R B (in third pic). I reached out to a technician in Arena about it, but he said that particular mosfet is scarce, that i could use mosfet Irf 740 (in fourth pic). He advised that, if i decide to use the Irf 740, i will have to change all 4 output mosfets as well so it doesnt spoil again. Guys, please what do you advise? I do not exactly have the luxury of time to order for the mosfet from Aliexpress
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Re: Solar Energy, A Complement To FTA by TechGeek777: 1:05pm On Dec 03, 2022 |
Please guys is it safe to use 350W Jinko Panel * 4 (i.e 1400W) in 24v system using MakeSkyBlue 60A CC, considering the CC Max allowed Watts @24v is 1440W? |
Re: Solar Energy, A Complement To FTA by odimbannamdi(m): 1:07pm On Dec 03, 2022 |
NiyiOmoIyunade: Thanks for weighing in, Oga Niyi. But, just out of curiousity, aside this incidences of inverters getting damaged, are there other disadvantages or risks of improper earth connection like in the case i stated earlier? Then, are there significant advantages of having a proper earth connection as well? |
Re: Solar Energy, A Complement To FTA by odimbannamdi(m): 1:13pm On Dec 03, 2022 |
TechGeek777: I guess so. I use 2 units of 540w Jinko panels (1080w) on a 12v connection with Powmr (similar to MSB), even though the max PV input power for 12v is 720w. I was so scared that the CC would fry when the sun peaks, but it is still holding up well. I think there is tolerance allowance. And as long as you dont exceed the max VOC, you should be fine. 1 Like |
Re: Solar Energy, A Complement To FTA by TechGeek777: 1:30pm On Dec 03, 2022 |
odimbannamdi: Wow that's impressive, I was initially planning to use 400W jinko, but fear of the CC getting damage as stated by the manufacturer is while I consider 350W. I understand the VOC should not be more than 105v @24v. Jinko 400W VOC is 49.8v @STC. Could it also be safe to use Jinko Half Cut 400W * 4 (1600W) same @24v with Makeskyblue 60A? Also have your Powmr ever produce above 800W? |
Re: Solar Energy, A Complement To FTA by NiyiOmoIyunade(m): 1:34pm On Dec 03, 2022 |
I guess I need to learn to communicate better or say much less or both +100 for not connecting DC negative to earth in any scenario - it can only help in limited cases and always increases the risk of catastrophic failure by a large amount when things go wrong. contease: |
Re: Solar Energy, A Complement To FTA by odimbannamdi(m): 1:49pm On Dec 03, 2022 |
TechGeek777: I am scared of answering the question in your penultimate sentence, make you no find me come house... ...but going by my current set up, I would do so if I were in your shoes. In fact, I actually have 4 units of 540w on my roof, but I have only 2 connected since I am on a 12v connection. When I upgrade to 24v and connect all 4 units, I should be doing x2 of what i am currently doing now, on the same CC. But, let more experienced folks give their advise as well. As to the last question in your last sentence, yes it should. I have observed it do 762w before, so it is very likely to have done 800w and more. I don't always observe it 2 Likes
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Re: Solar Energy, A Complement To FTA by NiyiOmoIyunade(m): 3:18pm On Dec 03, 2022 |
The protective earth is there for safety - it is inert and does no work until a surge hits or a local fault occurs and then it offers a path of least resistance through the system so that the fault or surge can pass through and be sunk into earth without damaging the equipment - With a proper protective earth in place, one can further add SPDs to speed the surge or fault away from the protected system and limit the voltage rise seen by the protected equipment. An example of a local fault is when a live wire touches the chassis of a piece of equipment or other such mistake or fault energises the case - proper protective earth connection will prevent someone coming in contact with the now live chassis from being electrocuted. So yes your equipment and energy generators/processors should all be connected to protective earth at the very least or else they are unprotected from an incoming surge or local fault. There are 3 major external ingress points for surges to hit a facility 1) From the mains incoming line - the service wires carrying power from the national grid to local street transformers are like huge antennas for lightning, although these are usually connected to protective earth at various points in the network and the transformer, large enough transients can pass through and damage appliances in a facility - best option is a good protective earth in place and SPDs on the mains incomer as well 2) Nearby hits and induced surge in cables and metal objects in the facility - all exposed outdoor metal (generators, antennae, dstv dish, solar panels, comms and power cables etc) can pickup induced surges when lightning strikes nearby - this is why it is recommended to connect them all to protective earth so that the surge can sink safely 3) Direct hit to building or exposed objects - this is a force majeure item so expect total obliteration and give thanks if you escaped with your life - there is really no protection against a direct hit. However a mitigant to direct hits are early streamer devices mounted atop the facility - these will pickup surges while still at the early stages and send them to the protective earth So if you have panels with your inverter then your risk increases as the panels can pickup static electricity or some surge transients and pass them through your system - a common failure mode for poorly earthed or unearthed systems in overnight rain accompanied by lightning strikes and the homeowner wakes up to a dead inverter - this damage easily avoided with a proper earth connection in place. You also do not want your equipment to electrocute someone or cause a fire where a few rods sunk in the earth would have saved the day. For your inverter that burnt a FET I cannot say what the root cause was - looks more likely to be overload - most line surges damage the input stage. odimbannamdi: 2 Likes |
Re: Solar Energy, A Complement To FTA by Ajanidokun: 3:27pm On Dec 03, 2022 |
Good day, Please recommend a very good 100amps lead acid battery. |
Re: Solar Energy, A Complement To FTA by Jefferyzz(m): 3:51pm On Dec 03, 2022 |
Yes. Connect it in 2p2s. Ie connect 2 pairs in parallel n connect the pairs in series. If d panel nah 500w say 50v 10a. U'll av 100v 20a flowing through ur wire. Make sure u check ur panel max series fuse. N use the rated fuse for d penels Incase there is a short. So ur panels can b safe. TechGeek777: 1 Like |
Re: Solar Energy, A Complement To FTA by Jefferyzz(m): 3:53pm On Dec 03, 2022 |
I remember this cracked panels, I was scared to buy den. odimbannamdi: |
Re: Solar Energy, A Complement To FTA by Prince3(m): 4:13pm On Dec 03, 2022 |
NiyiOmoIyunade: Honestly am enjoying education argument am actually learning a great lot from both of them, even though they contradicting each other |
Re: Solar Energy, A Complement To FTA by TechGeek777: 4:19pm On Dec 03, 2022 |
odimbannamdi: Thanks |
Re: Solar Energy, A Complement To FTA by TechGeek777: 4:40pm On Dec 03, 2022 |
Jefferyzz: Noted with thanks, since 380W won't cause damage that's what am going for. It has Isc of 10.77a, Max series fuse rating of 20A, with 2p2s that will be (10.77 * 2 = 21.54A). Do you think 30A fuse will be too much or should I stick with manufacturer recommendation of 20A fuse? |
Re: Solar Energy, A Complement To FTA by FEGEITOK: 4:52pm On Dec 03, 2022 |
I wanted to ask, but I guess this is the right time. Should those electricians who like to cut off the earth wires of electrical equipment be executed for malpractice? That was harsh, I meant to say should they be charged with malpractice? 1 Like |
Re: Solar Energy, A Complement To FTA by Polaris1: 4:58pm On Dec 03, 2022 |
FEGEITOK:I'll chip in - One good (or bad) cut deserves another Should those electricians who like to cut off the earth wires of electrical equipment be castrated for malpractice? |
Re: Solar Energy, A Complement To FTA by NiyiOmoIyunade(m): 5:05pm On Dec 03, 2022 |
They should be guillotined - my current location the electrician was paid for 4mm2 wire for all AC and heater lines, enough to cover both Live and Neutral and Earth wires, he switched the Earth wires to 1.5mm2 because 'he felt 4mm2 was overkill'. I fired him immediately I discovered the breach and got him to pull out the 1.5mm2 and deliver the 4mm2 he was paid for. Yes 4mm2 earth wire per AC is overkill but na code be that (to match the main conductors), na wetin I want be that and na wetin I pay for be that. A recent job, the client had AC neutral wire looped to some lighting points, reco to separate the wires and the electrician goes to use the existing 2.5mm2 for the lights and 1.5mm2 for the AC 'because he only saw 1.5mm2 to buy' I quietly texted the client to better go find a proper electrician else I would just hands off support. Electricians really do the most and it is so difficult to find a half decent one. Most do not even have a basic multimeter for any informed troubleshooting. FEGEITOK: 1 Like |
Re: Solar Energy, A Complement To FTA by FEGEITOK: 5:14pm On Dec 03, 2022 |
NiyiOmoIyunade: They installed my A/C and cut off the earth wires. My brand new Daikin A/C. Correcting it first thing on Monday. Thanks a million |
Re: Solar Energy, A Complement To FTA by GloriousGbola: 5:18pm On Dec 03, 2022 |
FEGEITOK: I'm not sure many of our artisans are actually registered. |
Re: Solar Energy, A Complement To FTA by Obnoxious2001(m): 5:28pm On Dec 03, 2022 |
NiyiOmoIyunade: Oga niyi how do I start studying this electrical codes. Am a student (marine engineering) am aiming at focusing on marine electrical /electronics systems. |
Re: Solar Energy, A Complement To FTA by NiyiOmoIyunade(m): 5:42pm On Dec 03, 2022 |
We are actually not so far apart - Oga J believes he will get more safety from an isolated PV earth - I believe he is better off creating an equipotential bond across all buried earth electrodes both because he gets a much bigger fault sink with the combined earth electrodes and also because he would eliminate the risk of step/fall potential killing people walking between two isolated earth rods and also surge induced voltage gradients between the rods creating a fault condition/loop that could damage the very equipment he was trying to protect. Electrical code looks at all the possible fault and failure modes and selects the approach that guarantees the most favorable outcomes for personnel and secondarily equipment in the most likely to occur fault and failure scenarios - in simple English a lot of modelling and assumptions and educated guess work goes into making the codes up so they are not infallible nor do they cover all possibilities, only the likely or feasible scenarios. In practice an isolated PV protective earth would be reasonably effective both because the solar panels did not take a too massive hit and also because the sunken rods are sufficient to sink whatever faults hit them. If a larger fault than the isolated earth rods could sink happens then the risk I mentioned that the codes are trying to guard against crystallises. As you see so many ifs and possibilities - in practice luck and time and chance play a big role so a totally unearthed building could go for years unscathed and someone who did it 100% right or 80% right could still suffer catastrophic damage. The luck of the draw plays a major role in the outcomes we get. Prince3: 1 Like |
Re: Solar Energy, A Complement To FTA by Jefferyzz(m): 5:48pm On Dec 03, 2022 |
Yh. Stick to the manufacturer max fuse TechGeek777: |
Re: Solar Energy, A Complement To FTA by coldcandy: 7:20pm On Dec 03, 2022 |
TechGeek777: You will need two of the 20A fuse. One for each series connection 1 Like |
Re: Solar Energy, A Complement To FTA by odimbannamdi(m): 9:57pm On Dec 03, 2022 |
NiyiOmoIyunade: Thank you very much for this insightful and details response, Oga Niyi. |
Re: Solar Energy, A Complement To FTA by TechGeek777: 10:18pm On Dec 03, 2022 |
Jefferyzz:Noted thanks |
Re: Solar Energy, A Complement To FTA by TechGeek777: 10:19pm On Dec 03, 2022 |
coldcandy: Noted thanks |
Re: Solar Energy, A Complement To FTA by fhranchez(m): 11:15pm On Dec 03, 2022 |
Hello solar gurus, sorry to disrupt your earthing argument. I have another argument myself that ensued between me and a installer this evening. I was lamenting about the 40% drop of amps from my panels this dry season to him and suspected the culprit to be dust & heat combined. To my surprise, he insisted that dust was a minor factor reducing my panel output. He diagnosed my failing battery as the major factor for the amps drop. So please, is there any way a weak battery can result to lesser output from my panels? 1 Like |
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