@ Waziri and @Pranil.
Thanks so much for your comments. God bless you.

@kiekie
I have no intention to disparage anybody.
My aim is never to win an argument here. All I desire is just to pass the right information across. Sometimes I think it is a duty. I have friends who have been seriously injured, properties burnt and millions lost before. Part of the root cause is information gaps.

I think we all have a moral obligation to always seek the truth. One holy book says the truth will make us free.

I think I am done with this CB topic.

mrsdaniel:


Nice argument but you both are likely on same page with your comparison above.Your inverter which we didn't get the brand name has 175A whilst his own 5 KVA came packaged with 200A types for reasons you said you dont really know, haha.if 200A will trip and protect his own system from gruesome damage,we really need to save the stress arguing vain most times as breakers have safety trip reasons installed as the op stated too regarding DC usage.most Nigerians generally don't care about all these ratings real life application,we mostly know and nobody wants to order breakers for experiment and it ends up tripping for no reason.y'al both all have a point I think.My 2cents

Neat setup I must say to Makavele.how is the performance of the slim batteries ?
CC:Makavele

It is clear you don't understand my message. This is not vain arguments. The reason why these rating of circuit breakers are put on inverters I do know. I have been in this field for close to three decades. Kiekie is not entirely wrong either.
My inverter did not come with one pre-installed. I have an inverter panel of same brand that came with one. These are two different things and you have to select the right panel for your application.
For your inverter, have you wondered why the manufacturer did not put 500A, 1000A or even 50A in there. Like you said, most Nigerians don't care about these things.
Many inverters do not come with an inverter-battery DC breaker as part of the setup. It is an important part of the jigsaw puzzle. If it is a DIY, one has to determine the right one to put there.
Putting the right one there means avoiding nuisance and unnecessary trips. It also means the CB will do it's job when required.
I can tell you many people depends on threads like these for education and to make the right decision. Putting the right message there goes a long way in helping others.

kiekie1:


Bro, dnt worry about all that theoretical explanations as its not new tho . we see so many DC 250a catridge disconnect in various installation designs for a reason and don't presume they are mistakes or the fuses don't blow up when you mistakenly misplace DC polarity .. I made clear illustrations with Netherlands Cyberpower 5kva 48v design with 200a DCB and can go on & on but I dnt really cherish typing handouts... I once was asked a question by a known company on why most people use DC breakers for DC isolation , dnt you also think AC breakers rated at same amps works on PV combiners too since the sole function isn't to trip when functional but only to prevent further bridging/arcing > fire damage .. Rather than undersizing a load bearer breaker , why not simply use 150/250a DCB and let peace reign on the said 5 or 6kw system designed for heavier surge loads because the sole function which its used for are basically for disconnection/maintenance sake and wrong polarity safety ! I rest my case ... Cheer's

Bro. I am not writing here for typing sake or to prove 'I too know'. You would have noticed I rarely make contributions.
My explanation is not theory. This is pure practical. I have a 175amp DC breaker on my inverter panel which is a 48V DC system. On 24V version, I know the breaker size is 250Amp.
The question is why did the manufacturer decide to put these sizes there? The breakers are not undersized, neither are they oversized. The number one reason is not Isolation. It is also not maintenance.
If you try to find honest answers to this question, I am sure everything will become clear.
I am a learner as long as I live. Cheers

kiekie1:


Namesake free that matter abeg ..Makavele is a practical man not theory .. Most pure sinewave 5kva inverters which isn't upto 4kw power use factory fitted 200a DCB .. Cyberpower is a good example! Bluegate 2kva uses 100a dcb etc .. That power starlight 5kw inverter you see in pics is a major load bearer with high surge capability and it won't make much sense using 125a small DCB for its DC cables as 250a will very much trip on practical wrong polarity mistakes and also carry basic,heavy loads needed as a 5kw or 6kw does without DCB tripping or overheating ! Cheer's

The DC circuit breaker should be sized based on the maximum current the installed inverter-battery cable can safely carry. Oga Pranil has reiterate this point several times.
Breaker and cable requirents for a 5kva/24V inverter is different from the requirements for a 5kva/48V.
I think the correct sequence should be as follows.
1. Determine the maximum current that will flow through the system during charging and inverting. The inverter manual will help with this.
2. Choose a cable with a CSA that will safely carry the maximum current. The more the distance between inverter and battery, the more the cable size. There are other considerations e.g conduit or open air installation etc.
3. Choose a breaker below the cable ampacity rating as determined in 2 above.

quote author=makavele post=69564967]And the final look . . .

Replaced the sockets with 20A switches for input and output disconnect; the 3rd one up is for the automatic water pressure booster.



[/quote]

makavele:
So at is my battery bank stands at: 19680 kWh and panels at 3kWp.

The only issue I am having now is some of my batteries are out of sync.

Would have to order more balancers before it's too late.

And I think I would have to create a dedicated earthing rod brouhaha for the inverter system; because

I am having issues with that annoying un-grounded current flowing through the inverter chassis when I am standing barefoot on the floor.

How do I fix this please?

What a wonderful DIY job. I have seen quite a few DIY and ones done by 'installers'. This one will rank among the very good ones. Board is well arranged. Cables are well crimped, insulated and routed. I can connect with your thought process. I know you must have spent a lot of times thinking things through. It is not easy. Weldone sir!

I have the following suggestions to make. You have already done almost all the hard work so these are probably improvement opportunities.

1. Replace the 20A switches with AC circuit breakers. Circuit breakers are the right component for your inverter input and output. They will serve two purpose. They will serve as disconnect and they will also protect your cables and inverter in the day of trouble. Cost is about the same as 20A switches.

2. Looking at the final picture, I can not see any protection for your inverter cable to battery. If it is there all well and good. If it is not there, there are different methods you can use. You can use a battery disconnect in series with an inline fuse. Alternatively you can use a DC breaker which will serve as both disconnect and protection. I prefer the DC breaker option.

3. For the battery issues, HA02 will do the magic. Oga Niyi has done justice to this one already.

4. Earthing.... earthing issues discussed some pages back. There is no 'one rule fits all' All inverters are not same. One good starting point will be to look at your inverter manual for earthing requirements, then move forward from there.
To avoid writing an epistle I have to stop here.

Weldone sir!

NiyiOmoIyunade:
Nothing much Sir.

While discharging/using the batteries the the 150Ah ones will give up all the useable power in them and be greatly stressed in the process - the 200Ah will still have some power left in it so it should not strain as much.

When charging the 150Ah batteries will be overcharged and stressed/boiled in the process. The 200Ah battery may not get a full charge.

Very soon all the 3 batteries will die. The 150Ah ones will die first from over charge and over discharge while the 200Ah one will die later from sulfation and undercharging.

What an analogy. All die na die. The end result will be to sell the batteries to Kiekie as scrap.

Barezzi:
I use mine with a 2kw hotplate and 2kw electric kettle simultaneously every morning 5 days a week for almost a year now.
This is with other loads of fridge, booster pump and other base loads.

I use a 10kva Gennex Inverter (Axpert clone).

This must be a very good ketekete(horse)
Gennex Inverter (Axpert clone) bookmarked.

NiyiOmoIyunade:
Oga Chris.

You are probably right in the general case. But for this specific Zinox IPowerPlus I have ascertained it easily gets fried if you use an iron or microwave or other resistive load on it. Perhaps one could get by with resistive loads under 500w but certainly a 1.1kw microwave and 1.3kw iron used separately but on a regular basis ruined my first Zinox 5kva within 3 months and the peak load never passed 2.2kw at any time - meanwhile said inverter runs 2 units of 1hp ACs with ease at another location.

After Zinox fixed it under warranty the first time, they warned me strictly to never iron or microwave with it again - same inverter is still firing strong in my Ibadan family house till date.

People that use irons and microwaves on the Axpert type inverters typically stack two or more inverters to share the load.

Very strange. I am surprised a 5kva rated inverter will find it difficult to power a 1.3kw resistive load. I suspect the nameplate rating of the inverter does not match the actual real rating. Well, now we know. Thanks for sharing

makavele:


no wonder the batteries died .

roy solar on top 4 x 200ah battery

hmmm

OMG. Not this thing called Roy again.

efuro:




Try this and thank me later.
It is the lowest I could get.
I rarely use PHCN for ironing, it is of no strain on my microtek inverter.
It intermittently draws 3A-AC/580w Max at start for about a minute or so.

Thanks

Reprobate:


hmmm, who do I believe now??.
earlier, some1 said it doesn't matter...that's its only the runtime that it would reduce..i feel its not healthy for the battery, but need science to back it up.
when fully charged, at 50.4v, my 2kw steam iron draws the fla batt voltage to 48.4v, I want 2 know if there is any harm in continuing with this practise

I advice you get a small iron for inverter use. I once got a 700W iron at Spar some years ago. I have tried looking for the same brand/type everywhere without result. Anybody knows where I can find one?

pranil:


I beg to differ. T[b]he only way of reliably testing of earth connection is using something called earth megger[/b]

https://www.tester.co.uk/megger-det4td2-earth-tester?gclid=CjwKCAjw0ujYBRBDEiwAn7BKtxVskY0Ebjn7_IDanAUeQ2PbLikI69LuLmSiKQYo8X56c5zYl-vlZBoCPHwQAvD_BwE

- If the earth is even connected by 1.5 mm2 wire the light bulb will light up or multimeter will show low voltage. The earth is supplied already from the disco in a good installation by neutral grounding and hence neutral will always show low voltage with earth.

A good way to check if the Neutral is earthed at home is to switch off NEPA at the entry point ( including neutral) and then measure the inverter output neutral to earth you will be surprised to note that most inverters will show balanced voltage with respect to earth say 110 V ( P to E) and ( 110 N to E)

The higher end inverters have a sperate grounding relay which actuates the main relay ( Victron) or auxiliary contact ( SMA. even newer Ipower models) earth to neutral short on the failure of the grid



That kind of earth is enough to reliably trip a ELCB ( earth Leakage) circuit breaker but may not be strong enough to sink a lightning surge ( or switching surge

typically earth resistance measured ( when isolated from earth bar) should be less than 5 OHMS ( IEEE) , 10 Ohms ( India) 25 ohms ( USA)

In layman's terms during lightning strike, the earth can carry several kiloamperes of current and a high resistance path may raise the circuit potential above 1.5 KV where the normal equipment may fail or people can get shocked

Also there are two values to be concerned with earth Touch potential and step potential. Both concern with human safety. A weak earth can raise a potential along the earth point potentially shocking people on failure of insulation of the equipment



M[i]y advice is to sink one more rod if you are not sure and connect directly to your earth bar with a solid connection without a break -

Typically if the property has large generator e.g. 20 KVA and above you can easily trace and use the generator earth rod as most generator companies will sink a Rod close to the generator and connect to neutral and generator body
[/i]

@Oga Pranil. Thanks a lot for your useful insight. I have benefited a lot from your contributions.

I am not an expert in this particular section of Electrical eng., so I stand to be corrected.

Grounding/Bonding is a critical part of RE installation which many people often neglect. I am not an installer but I have seen quite many installations. In most cases, grounding/Bonding is non-existent. In very few cases where it is available, it is not properly done. The grounding cable is usually too small and the terminations are always horrible.

As far as I remember, introducing another ground rod is not fault proof if not properly done. Most home installations In Nigeria have their neutral to ground bond done at the distribution board in the house and connected to a grounding electrode which is buried. If another ground rod is introduced anywhere in the building then it is recommended to connect the two earth/ground rod together to force them to be at the same potential all the time. In many cases, this is not practical as it is dificult to locate where the first earth rod is buried. If this is not done, then the very step potential we are trying to run away from could cause severe fault current to loop between the two earth points and connected equipment and cause damage.

Concerning grounding, I think each inverter should be taken on its own merit. I know that some transformer based inverter(premium brands) have their AC side electrically isolated from the DC side. Some do not. Many transformerless inverters do not have this feature. Some inverters have ground switching features.The grounding requirements for each type will be slightly different. For sure, the manual of a good brand will clearly state the requirements.

This subject of grounding may appear small and trivial but it is very huge.

Having said all these, I think extra ground/small ground/poor ground is far better than No ground.

Again, I stand to be corrected.

pranil:




Although to be fair I am using two ROY charge controllers in my current setup and they are doing their job wonderfully.

....

Keeping the generator starter batteries charged with 20 Watt panels

What did I buy ROY -- Their colours matched my generator body so easy for me to know which CC is charging the gen

And their USB output is also wonderful - I run a Small LED LAMP on them and the Garner is happy charging his phone . What more can you ask for 9000 NGN

I am rolling on the floor....

On a more serious note I suggest that wonderful people on this forum start compiling the rules/commandments of RE installation in Nigeria. It has been over 400 amazing pages of discussion spanning over 9 years

Saipro:


For most "Roy" installations I've seen, installers would use a horrible pair of 4 - 6mm (one for +ve, the other -ve) to run double digit amps over 20 - 50 metres, amongst other blunders. These cables would even have poorly connected joints. Very poor system design can often be blamed. I do agree culprit Roy has poor charging algorithms, no voltage correction and worst of all, no temperature compensation.

bigrovar:

Roy is bad no point calling a spade a gardening tool.

Saipro:
Seen a lot of discussion on the Roy Solar PWM CC over the past two pages. Is the grouse with the brand or with use of the PWM CC (the lines are blurred during the course of discussions)?

My point: for smaller systems (translated as being under 1kW of PV array) with short distance between the array and CC, PWM might be the cost effective way to go (considering Nigeria's climate).

I have 2 PWM CC in my itinerary (Xantrex C60 and Midnite Kid), of which one is in use at the moment for powering my DC security lights and their performance is nothing if not ideal.

Of course, these statements rely heavily on the VoC of the panels and nominal voltage of the system being optimally matched.

I think if used within their boundaries, the premium brand PWM CC will do a good job.
Comparing xantrex, midnite with roy may be like comparing a Mercedes-Benz with keke.

I am considering adding one more rule to my solar rule book. Thou shall not touch anything called 'roy'.

They are not really interested in God. All they want is the 'solution'. They don't care where it comes from. If it comes from church, so be it. If it comes anywhere else, so be it.

godspeed:


Thanks boss

The battery is still new, bought it two weeks ago

On option 2, I don't even use the battery in the afternoon at all as I'm always at work. I only need the battery to work for like four hours when I return home in the evening.

Pic of the controller

Roy solar ke! You better remove that CC if you want to sleep well. I advice you contact the reputable suppliers here for good replacement. If possible, start your DIY from there.

mcTrinity:


looks like I'll make the panels 20# or 24# since I'm looking at about 18A for each string with the Magnum MS4348

Don't forget, the recommended max PV input on the PT100 is 6600W.
Theoretically, that should be about 20 pieces of 330W panels.
If you can hit that ceiling with weather situation in Naija all year round is another point of discussion.

Personally I will not be comfortable with 24 panels on one PT100 CC. At this point, you might have to start thinking of another CC.

mcTrinity:


thanks...

that's what we (myself and client) are trying to achieve; to charge without PHCN. Already gotten 16# of Canadian 330w panel with PT-100. About to acquire 12# of 12v/200Ah battery.

trying to confirm if at worst weather situation, the Magnum will be cable of charging the 3 strings.
looks like I'll make the panels 20# or 24# since I'm looking at about 18A for each string with the Magnum MS4348

I have an almost exactly similar setup.
I have 16 340W Canadian solar panels in a 4X4 configuration.
Pt100 charge controller
48V, 630AH Trojan batteries.
MS4348 Inverter
Magnum Panel and other accessories.

The solar panels are well capable of charging the batteries. CC wakes up as early as 7am. Even on cloudy days, batteries are on float by 1pm. PHCN supply is terrible in my area. I never bothered to connect it to the inverter. AC input breaker is permanently switched off on the Magnum Panel. Inverter charging on the remote is left disabled.

I encourage you to go for it. This system will give you peace of mind. Mine is a DIY.

mcTrinity:


Thanks very much Big bros...

tried browsing it and I'm seeing different things. saw 55ADC in one of their catalog. Also saw 60ADC in MS4048 manual

Thanks...

MS4124PE - 105A DC /24V System @25degreeC
MS4348PE - 55A DC /48V System @ 25degreeC
PT100 - 100A /Charge controller

I use MS4348. I never charge with PHCN though.

Must the name end with 'son'

mcTrinity:
Good evening house,

I'm trying to improvise a PV combiner box using 4 circuit breakers and breaker box.

Attached is a sketch of how the connection will look like.

The PV combiner box is for 16# of 325w panels (4X4 configuration)

The circuit breakers located in the breaker box will be rated 16A (DC) or 32A (AC)

Correction is strictly welcomed...

Thanks

I have 16, 340W Canadian solar panels on a PT100 in a 4S4P configuration.
I have never hit the high Voc range starting at 187V. The most I have seen is 172V.
4X4 configuration will definitely work. My CC wakes up very early in the morning - Sometimes before 7am. It works on cloudy days and sometimes rain.
For PT100, 4X4 is a good way to go.

mcTrinity:
Good evening house,

I'm trying to improvise a PV combiner box using 4 circuit breakers and breaker box.

Attached is a sketch of how the connection will look like.

The PV combiner box is for 16# of 325w panels (4X4 configuration)

The circuit breakers located in the breaker box will be rated 16A (DC) or 32A (AC)

Correction is strictly welcomed...

Thanks

I have 16, 340W Canadian solar panels on a PT100 in a 4S4P configuration.
I have never hit the high Voc range starting at 187V. The most I have seen is 172V.
4X4 configuration will definitely work. My CC wakes up very early in the morning - Sometimes before 7am. It works on cloudy days and sometimes rain.
For PT100, 4X4 is a good way to go.

Monlo:



Dont mind my english which is on purpose "i cant fit shouting" hahahahahahah

That line" I might consider arranging boys to make his gen disappear" got my ribs cracking lolz.Funny u

If the Gen is a 500kva noise-minator. 20 boys no fit lift am.
Consider praying the Gen to death.

dapsyra:


15,000 cycles

15000/365 = 41+yrs
Is this not cheaper in the long run?

davodyguy:
takes minimum of 7 days and max 60 days, depending on the merchant.

They deliver via Nipost and sort out clearing themselves. All you do is to collect from Nipost close to you

Thanks a lot

Awesome thread. This thread has inspired me to embark on my DIY solar project. Many thanks to everybody who contributes/educates people here.

For people who order things regularly on aliexpress, how long does it take to receive the ordered items in Nigeria?
Is there any issue with customs?
Which freight company do the suppliers normally use?
Is it better to use a logistics company to ship from China?

Answer to these questions will be very much appreciated as I need to get some items for my upcoming solar project.