My answer may be late because am not always on the forum. I hope it still helps.
It may be regarded as a TT installation if PHCN only brings live and neutral wires into a building. The following will address solar PV systems in a TT building. The building will need a TT earthing for protection from fault currents arising within its electrical infrastructure. The building and the solar PV both need earthing for protection from lightning strikes.
TT installations should have a local earthing with sufficiently low electrical resistance to earth to ensure correct operation of the earth fault protection devices. It is not enough to drive an earth electrode into the ground and attach it to the earth bar in the distribution board. It is very important that the TT earthing is correctly designed and installed and combined with RCDs. Its impedance should be tested at least once a year to be less than 100ohms. Professional support with electrical and solar installation, commissioning, inspection and testing, and trouble-shooting is available at ritility.com.
Your ‘electrician’ may be advised to remove the neutral to earth bond at the distribution board if PHCN already does this at the transformer level, and to connect the earth bar to suitable TT earthing of the building. Your solar PV should have its own separate earthing rod. Periodically test TT earthing for sufficient impedance!! An equipotential bond should then be made between the earthing rods, with SPDs, MCBs and AFDDs combined as applicable. A lightning arrester system is also needed.
Finally, if a solar PV hybrid energy system with its own battery storage is to be connected in parallel with PHCN grid, it is good practice to install a safety system that will automattically disconnect the energy system from the grid in even of grid outage. This is to prevent back-feed of power into the grid.
It seems that, in Nigeria, anyone (ati ájá, ati ẹran) can market themselves as installers of electrical, solar electrical, or other dangerous energy systems without the requisite training, tools, experience, or compliance with safety standards. However, just because it works does not mean that it is safe.

NiyiOmoIyunade:
I have a question for the electricity buffs in the house.

A friend is constructing an office complex and his electrical contractor wants to install an RCD/RCCB at the service entrance to protect the whole facility (all personnel and devices downstream of the RCD/RCCB)

In order to 'improve the speed at/certainty with which the RCD/RCCB could respond to a fault and disconnect the supply', he has already jumpered/connected the Neutral and Earth bus bars in the DB with a 16MM cable - this installation is here in Lekki - while I know this practice of linking Neutral and Earth is common practice in North America and even mandated by their electrical code, I am yet to see it done here in Nigeria.

I had raised a similar question previously - what do you think? Should Neutral and Earth ever be linked here in Nigeria (I believe our transformers are star/wye wound and the neutral wire center tapped - dunno if PHCN actually Earths their neutral wire at the transformer)

Does this practice help the performance of an RCD/RCCB in any way?

The office will also have solar power tied in(where I come in ) - I am struggling seriously with wiring the CC Earth terminal to that same Earth bus bar in the DB that already has an AC neutral connected to it.

pranil:

all your problems will be solved once bmv is connected to ccgx

after connecting the BMV

1. set the BMV is the monitor in CCGX - See image --submenu settings - system setup

2. Switch on also has DC system - submenu settings system setup

That way the CCGX used the current from battery and Multi to calculate current taken by loads. Beware though since you are using flexmax the BMV will not report all current produced during day as some of it will be consumed by multi and load.
if you want close monitoring you will have to change CC to Smart/blue solar from victron

Problem solved as suggested, with ve.Direct cable.

A 2014 hack that ports old model BMV600 series to a raspberry pi
https://fab13n.github.io/elorn/software/2014/05/11/raspi-1.html

Victron would do well to point out very clearly on their BMV product pages, the need to purchase a Ve.Direct cable! Or just ship one inside the box of every BMV sold.

Saipro:

It's more than just a matter of cable pin assignments. It's a serial to USB translation at specific baud rate so you'll need extra hardware for that. I'm about to make my own cable so I could give you feedback when successful (or not).

Indeed, a direct connection using the 4-pin audio cable did not do the job. Kindly share your learning as you go.
I might just order a bunch of ve-direct to usb cables, and then connect the CCGX, BMV and other devices together to a powered usb hub.

bigrovar: my search of the archives indicates that you were trying to diy a ve-direct to usb cable back in June. Can you share your learning, please

There are some hacks involving ve-direct cables shared online.
This one replaces the ve.direct RS232/Serial-to-USB cable http://beta.ivc.no/wiki/index.php/Victron_VE_Direct_DIY_Cable
A youtube video with incoherent explanation of a ve-direct diy can be found https://www.youtube.com/watch?v=wkZpI_BRmB4
Another incoherent ve-direct to bluetooth hack, with code can be found https://www.youtube.com/watch?v=wkZpI_BRmB4

pranil:

all your problems will be solved once bmv is connected to ccgx

after connecting the BMV

1. set the BMV is the monitor in CCGX - See image --submenu settings - system setup

2. Switch on also has DC system - submenu settings system setup

pranil, thanks
Presumably, the cable needed should be ve-direct port of CCGX to ve-direct port of the BMV
part ASS030530310 https://www.victronenergy.com/cables/ve.direct.cable
gbp21.47 https://www.amazon.co.uk/Victron-Energy-VE-Direct-cable-10m/dp/B01F9ESJVI/ref=sr_1_2?ie=UTF8&qid=1537184625&sr=8-2&keywords=victron+ve.direct+cable+10m

Can anyone share the pin sequence for the ve-direct cable because I would like to try to hack a 4-pin audio cable that I got from an old PC?

Saipro:

Works seemlessly with Fronius and a somewhat bumpy ride with SMA. Hoping to get a Primo or Symo someday. An ethusiast's dream.

A Primo works well for 1- systems. Be aware of the 1:1 rule for sizing the battery bank.

Awaiting a donor EV from which to harvest a Li-ion battery bank, at a more affordable price than buying Victron's. Another option may be BYD pre-packed with BMS or the raw CALB LiFePO4 cells to combine with Victron BMS.

I have a brand new unopened in box, Fronius Primo 4.6 in stock.

Thanks for the feedback. I hope no-one noticed the wrong times reported in my post above. 2:80pm indeed, not. It was 10:00am, 1:40pm and 2:08pm. Anyways....

The bmv712smart does a very good job of keeping track of the battery bank voltage and SOC. It is only necessary in the current system because of the presence of the Outback Flexmax FM80. The rascal is the MultiPlus, which needs to be physically switched off anytime PHCN resumes, and then restarted, before its SOC% adjusts to the reality of solar charging by the OFM80. I suspect that this may be due to the settings. I do not presently have ESS or any of the virtual assistants engaged: Just OFM80 connected to DC in, PHCN or genset changeover to AC in, the critical house loads are on AC1 out, and the non-essential loads on AC2 out.

The MultiPlus also does not assign any figures to the DC power display, although I have 3 computer DC fans and a 12v LED light connected directly to the busbars. Can anyone help resolve this? I can manually calculate the DC loads, but I would like to see it on the CCGX display.

However, I do not presently have a Ve.Direct cable... I will be ordering some Victron and Fronius products shortly. If anyone else is interested, please let me know so that I can bulk-buy and pass on the savings. Lagos 10-day delivery will be gbp4.75/kg while 21-day delivery will be gbp11/kg

Thanks for welcoming me.

I want to share a recent experience of using Outback Flexmax FM80 within the Victron ecosystem.
Issue: Victron CCGX (using the Multiplus as the default battery monitor) is confused by solar charging of battery bank by a non-Victron charge controller.

10:00am PHCN is off. OFM80 is charging the battery bank. Even in bright sunlight, with the OFM80 charging the battery bank upwards, the CCGX is reporting depletion of the battery bank SOC%. CCGX reports correctly that battery voltage is changing in line with the reports of the OFM80 and the BMV712Smart, but the CCGX SOC % is not correct.
1:40am PHCN resumes, and Multiplus switches to Float. OFM80 and BMV712 and CCGX reports similar voltage. But CCGX continues to show depleting SOC% levels even with both solar charging and PHCN charging going into the inverter, and battery voltage is going up!
2:80pm Eventually, the MultiPlus is switched off and restarted. After a brief pause, the SOC jumps from 55% Bulk to 85% Absorption. Within next 10 minutes, it jumps from 86% Absorption to 100% Float.
Recommendation
1. a Ve.Direct cable between the BMV712Smart and the CCGX that enables the BMV to be the reference battery monitor instead of the MultiPlus.
2. Alternatively, a contactor which stops and restarts the MultiPlus after a few minutes in order to enable the SOC algorithm within the MultiPlus to catch up. This would however mess with the UPS function of the MultiPlus, and adds complexity.


current system: 3.18kWp Solar Array = 9x270w Trinasolar Mono & 3x250w Solarworld AG Poly; Victron Multiplus 5kVa; Outback Flexmax FM80; Quanta Amaron 200AH@48v; 7.5kVa Kipor diesel genset; Gas cooker; Energy efficient appliances; Passive cooling & heating of buildings.

Hello fellow DIYers and solar pros..
I have been reading this topic for a while. Took 4 weeks of reading from the original GeorgeD1 post, through the many postings of kiekie1-the-dealer, Niyi-longname-the-guru, chris-dr-solar, makavele-the-inventive, and other esteemed contributors.

I am grateful for the community, and will contribute to this topic, mainly in areas of safety or control of solar and electrical installations because of my training as a qualified electrical contractor, and enthusiasm for sustainable technologies and smart home automation.

Remi