New Micro grid system on BYD batteries going in @ 11.6kWp

[PowerUser]

3 hours ago, Sarel said:

Gladly, they are called bootlaces. 

 

I assume, you will be using them to connect the cables to the CBs. Are they necessary or make any difference at all? Or you just want everything neat?

[Guest Sarel]

Correct assumption yes. Any wire that does not have a lug crimped on will get a bootlace crimped on. This is mostly for my OCD  and because of it....

There is a real benefit to crimping them on wires tho, it prevents strands from fraying and poking outside of where they supposed to go, so less chance of shorts and more reliable connections.

[Guest Sarel]

A bit more on them bootlace ferrules:

When the end of a multi strand wire is placed under a screw terminal, the strands of the wire will fan out as the screw is tightened and in extreme cases of over-tightening, the screw can even sever some of the strands of the wire. This can reduce the quality of the electrical connection and could lead to shorts. Using a bootlace crimp with all the strands captured in the ferrule tube makes for a reliable connection, that is also easier to remove and reinstall without damage to the wire ends. Further, it captures every strand, ensuring proper current carrying, preventing shorts and arcing/heating when properly screwed down.

[BritishRacingGreen]

11 hours ago, Sarel said:

A bit more on them bootlace ferrules:

When the end of a multi strand wire is placed under a screw terminal, the strands of the wire will fan out as the screw is tightened and in extreme cases of over-tightening, the screw can even sever some of the strands of the wire. This can reduce the quality of the electrical connection and could lead to shorts. Using a bootlace crimp with all the strands captured in the ferrule tube makes for a reliable connection, that is also easier to remove and reinstall without damage to the wire ends. Further, it captures every strand, ensuring proper current carrying, preventing shorts and arcing/heating when properly screwed down.

Do not know if it will be recommended for high power , but in control circuits the bootlace crimp is also a quality means  of joining two multistrand inputs on one connection. 

Edited September 2, 2021 by dropkick

[Guest Sarel]

1 minute ago, dropkick said:

Do not know if it will be recommended for high power , but in control circuits the bootlace crimp is also a quality means  of joining two multistrand inputs on one connection. 

Indeed you even get dedicated multi wire bootlaces for twin cables.

[BritishRacingGreen]

6 minutes ago, Sarel said:

Indeed you even get dedicated multi wire bootlaces for twin cables.

Ha, never to old to learn, never knew you get special ferrule for that purpose. Magic!

[Guest Sarel]

And also, for the sake of completeness, you get them uninsulated, I have seen up to 70mm cable versions. Oh scratch that.... 120mm cable version available but have never seen one  Ok ok 150mm version then....  no manual crimping here....

Edited September 2, 2021 by Sarel
Added correction

[PowerUser]

20 hours ago, Sarel said:

Correct assumption yes. Any wire that does not have a lug crimped on will get a bootlace crimped on. This is mostly for my OCD  and because of it....

There is a real benefit to crimping them on wires tho, it prevents strands from fraying and poking outside of where they supposed to go, so less chance of shorts and more reliable connections.

Thanks. Another question - why would you use the round bootlaces for the CBs instead of the ones with flat ends?

[Guest Sarel]

When the bootlaces are unused they are round, just like the wire. Smaller sizes are crimped with a bootlace tool and end up being about square (or 6 sided hexagons depending on the crimping tool dies) after crimping. Larger sizes are normally crimped with a hydraulic or electric tool, they normally end up being hexagon shaped.

[Guest Sarel]

Panel layout design

What Ended up happening to get these panels to fit my roof was the following.

As there was not enough space on my roof from front to back, to do the standard row spacing, I had to get creative. Also the roof slopes 5deg to the south or -5deg from horizontal.

I simulated the inter row spacing for a flat surface and then did a CAD drawing to see at what distance and height the back row had to be.

The first row of panels in front are at roof level and 33deg (38deg from roof angle) and about 1.3m in height at the back from the roof surface. The second row of panels are installed 1.3m behind the back of the front row and the bottom edge of that row start at 1.050m above roof level.Purple line represents Sun angle at 08:30 for June 26. Green lines are the panels.

This way of mounting the panels were the only way I could fit them on the roof space and have a half decent chance at not shading the back row. From 09:00 to 16:00 the panels are unshaded for a solid 7hours of Sun. It worked out to actually be almost 8 hours for the back row being unshaded in reality.

[Guest Sarel]

In a flash, lightning….

The house being as old as it is, have no surge protection or lightning protection at all. It is a metal roofed structure with a steel frame, almost a faraday cage but not quite. The general structure has a high attenuation rate for any RF, quite a bit higher in fact, compared to normal structures. My neighbour lost a tree a few years ago to a direct strike, tree exploded while I happened to look his way. Saw the event in real time. Nothing at my place was damadged tho.

There are volumes written about this subject and its very deep, but fascinating. I took from it enough to be able to select some protection for the PV System. Now that I am routing wires from above my roofline into the house, and connecting them to my house wiring, it's time to add the protection as there are now a lot more risk of damage.

National map for SA.

SAWS info based on the Viasala systems data. World averages map here

Lightning protection zones concept. Basically LPZ0a is direct strike and for LPZ3 there is little chance for a direct strike but likely induced V/A and spikes or surges. This from the Dehn Lightning Protection Guide.

We need a dedicated Earth ground spike for the PE connections everywhere. This includes the generator, solar panels and other equipment as well. It serves as the Lightning ground and equipment ground. Apart from the required Neutral Earth bonding done by the Quattro on LOM detected and isolation, we have to provide a dedicated equipotential to all equipment. I selected a class 1 + 2 device for each string, as well as surge protection for the generator.

 

More to follow....

[Guest Sarel]

More on prevention and safety....

It's a rather sizeable investment to protect, bolted onto an even larger investment in the property, and to not allow it all to burn down, let alone your loved ones in there with you. Down that rabbit hole we go. Lightning is just one aspect, fire fighting preparation and prevention and warning are some of the others.

I have 2 different types of fire alarms (smoke detectors), one is not connected to anything and in my kitchen. The other type are battery powered but operate via own alarm siren build in for local alerting, but also connected to Wifi for remote warning capability. This is the detecting and Alerting part of the system. (Sadly by then its almost too late, but we should wake up if sleeping pretty rapidly me thinks.)

Prevention is the most important part. So all connections on all cables are done with crimped lugs on the DC side of things and are fused where needed. All cables are protected from abrasion and installed in trunking where physical contact are prevented wherever possible. Extra this cables are used everywhere to reduce resistance and keep them temps down. All other cables are crimped with Bootlace ferrules as well. We want to eliminate the potential for high resistance connections (heat generation) or sparking. Temperatures will be monitored everywhere to serve as early warning and regular maintenance will be undertaken. Cooling fans cleaned, connection tightness verified etc etc.

Fire fighting, hopefully, will be last. One smoke detector on WiFi is installed inside the equipment room that also houses the BYD Lithium Iron Phosphate Battery. The other is outside that room but close, as a backup. This battery chemistry has a fairly low propensity for bursting out in flames, fortunately. For the Fire fighting duties we have a large CO2 system just outside the door around the corner to the equipment room. This is so that should there be a fire, we have a chance to get to the CO2 bottle.

I also have a nifty (IMHO) small nano particle unit that does not need regular servicing as a backup. This is a Firepal FP50 Portable Fire Extinguisher. Hint, it's the tiny red thing  and it's relatively speaking, not expensive. As the battery bank grows, more CO2 and FP50's will be added.

 

Its not suitable for type A fires tho! But perfect and safe for Electrical fires and electronic equipment. I hate DCP.

Be safe, later....

[Guest Sarel]

Inverters and wiring, oh my….

Time to build and wire the inverter system since all the panels are installed and all exterior wiring done according to code. No exposed wiring anywhere, everything enclosed in steel raceways and thusly UV and weather protected. All panel wires cable tied down so no flapping in the breeze here.

 

Because of this being a Micro grid, there are many switches and lots of wiring for DC, Control and AC. These have to be reticulated in separate trunking and I do not want the various signals to cross paths, thereby preventing interference and EMI/RFI. The inverters generate enough harmonics as it is.

It is difficult mounting all of this on a brick wall as most of the equipment were not designed to be installed like that. A hardwood plywood board was procured and all the basics mounted to that board while it was on a table, making it easy to work with and the equipment can be installed neatly.

 

Placed on top roughly as per the design to see where and how to reticulate wiring.

 

Since I designed a 3d model, we had a good idea for the start of the layout. At least the basics were in place.

DC design layout.

From here we started laying out cables for each of the three types, the DC side being first. Starting with the DC panel feeds, that got planned to where wires were needed. We have 2 DBs with the DC MCBs, Lightning protection and fuses. I elected to have the MCBs first so each array string can be isolated independently, followed by the Class I and II lightning protection and then a 1kV 20A fuse. When you switch off the breaker, you can safely work on any wiring or items downstream. All the safety devices are rated for 1kV as two strings are higher than 500V. One string is 150V and its MCB is rated for 500V.

The two hv strings are then fed to the Fronius string inverter. The 3rd string is at 150V and are fed to the MPPT controller that will charge the battery bank.

 

The battery banks wiring is separate and via a bus bar system as shown in an earlier post. Here I planned for a 48V DC led emergency light wired directly to the DC bus. This is in case the system trips or something goes horribly wrong on the AC side. Much better than trying to bite a flashlight between the teeth in the dark while trying to diagnose a fault or finding the tripped breaker or reset the inverter.

 

Now time to plan for AC.

We have the main incomer from the Utility grid via the main house DB to this sub panel DB. We also then have the return back to feed the house. The house is wired as all essential loads so only one Quattro output are used. Concurrent maintainability is paramount to me. In case of failure, upgrades or maintenance, I want o be able to isolate the complete system or part of it to be able to work on the system without disrupting my ability to power the house. Therefore I can bypass the Quattro and isolate it by using a changeover switch, effectively linking the incomer to the house feed.

Generator.

I do have a generator with surge protection, RCD and changeover switch on the second AC input on the Quattro. I can use this to feed the house directly instead of the Quattro inverter if need be and still isolate the inverters for maintenance if the need arises. Normally the generator will feed the Quattro inverter to assist battery charging in case of extended periods of no or low Solar generation, or to carry loads. This is designed with my concurrent maintainability and no load interruption strategy in mind.

The rest of the AC routing is between the Fronius string inverter output and the Quattro output thus forming my Micro grid. This output are fed to the house for normal operation.

 

Control.

I do have one device, the Ubiquiti network switch requiring a mains input to function. To help with this I added a few plug outlets on this board as well. This can then also be used to power a few mains items and as 2 usb chargers were included, even a phone and tablet can be charged from here. Any type of commonly available plug style supported here. These outlets are on their own 10A MCB.

 

The Cerbo GX device is key to managing the Micro grid and individual components. There are a fair number of ethernet and other control cables to be wired including the touch display module. All this was planned for and routed as well.

To follow, more on the build and wiring later.

 

[BritishRacingGreen]

On 2021/09/06 at 6:59 PM, Sarel said:

More on prevention and safety....

It's a rather sizeable investment to protect, bolted onto an even larger investment in the property, and to not allow it all to burn down, let alone your loved ones in there with you. Down that rabbit hole we go. Lightning is just one aspect, fire fighting preparation and prevention and warning are some of the others.

I have 2 different types of fire alarms (smoke detectors), one is not connected to anything and in my kitchen. The other type are battery powered but operate via own alarm siren build in for local alerting, but also connected to Wifi for remote warning capability. This is the detecting and Alerting part of the system. (Sadly by then its almost too late, but we should wake up if sleeping pretty rapidly me thinks.)

Prevention is the most important part. So all connections on all cables are done with crimped lugs on the DC side of things and are fused where needed. All cables are protected from abrasion and installed in trunking where physical contact are prevented wherever possible. Extra this cables are used everywhere to reduce resistance and keep them temps down. All other cables are crimped with Bootlace ferrules as well. We want to eliminate the potential for high resistance connections (heat generation) or sparking. Temperatures will be monitored everywhere to serve as early warning and regular maintenance will be undertaken. Cooling fans cleaned, connection tightness verified etc etc.

Fire fighting, hopefully, will be last. One smoke detector on WiFi is installed inside the equipment room that also houses the BYD Lithium Iron Phosphate Battery. The other is outside that room but close, as a backup. This battery chemistry has a fairly low propensity for bursting out in flames, fortunately. For the Fire fighting duties we have a large CO2 system just outside the door around the corner to the equipment room. This is so that should there be a fire, we have a chance to get to the CO2 bottle.

I also have a nifty (IMHO) small nano particle unit that does not need regular servicing as a backup. This is a Firepal FP50 Portable Fire Extinguisher. Hint, it's the tiny red thing  and it's relatively speaking, not expensive. As the battery bank grows, more CO2 and FP50's will be added.

 

Its not suitable for type A fires tho! But perfect and safe for Electrical fires and electronic equipment. I hate DCP.

Be safe, later....

I'll give you this , Mr Sarel , you seem to leave very little to the imagination regarding research and rollout. Well done. Good to follow you.

[Guest Sarel]

Thank you. I know it seems like a chameleon on a smarties box  but my brain just works that way.  Some people will say I am a very bad dinner guest, will talk their ears off about a subject nobody is interested in.... 

[Guest Sarel]

 I went with this for emergency backup at the equipment, also allowing cellphone charging. I also have a 48V DC Led driven directly from the battery bank for emergency light.

[Guest Sarel]

Making progress on wiring the system.

Routing wires out of sight behind the board. This protects my control and low voltage signals from interference. The Network is hardwired to ensure reliable network comms with all the harmonics generated by the Inverters.

Edited September 8, 2021 by Sarel
added routing

[Guest Sarel]

Progress made….

Some explanation required to points raised in here earlier. This is a brain dump for what I was thinking and considering while planning and building this system. It’s my attempt at documenting why the choices was made. A bit of overload on details, yes. Like I mentioned, buckle up buttercup

Some pictures on the progress.

4th phase to follow 

[FrederikSchack]

On 2021/09/01 at 1:25 PM, Sarel said:

Correct assumption yes. Any wire that does not have a lug crimped on will get a bootlace crimped on. This is mostly for my OCD  and because of it....

There is a real benefit to crimping them on wires tho, it prevents strands from fraying and poking outside of where they supposed to go, so less chance of shorts and more reliable connections.

When I lived in Denmark we always used single stranded wires and we basically have plug and play wall outlets, we just plug in the wires and are good to go, very efficient  Now here in Uruguay, I can only find multi stranded wire, it's a pain.

[FrederikSchack]

On 2021/07/22 at 7:06 AM, Sarel said:

First some background, then I will dig into why and how: After having being an independent consultant to Eskom (Escam) for 10 years till end 2014, I do have some insights into that place. I will leave that there. Since the recent announcement by DeRuyter that the Coal fired Plant will get less and less maintenance (also look at the LHS and RHS graph from Escam data below) its clear we have collectively, a very big issue on our hands.

 

 

Then on top of all, there are those with connections that aim to have the Utility driven into the ground for their own financial gain. You may wonder how that is possible you ask? Well now if the dilapidated Coal fired Plant, and the new Medupi and Kusile Plant are not reliable or efficient, Escam must get power elsewhere, more places to bribe and corrupt. Look for this no further than the Powerships tender or any of the investors behind the new Green energy Plants. Or the latest round of coal procurement contracts at more than double past contract prices, makes you wonder.....

This brings me to my Solar PV system and the reasons behind that. I refuse to subsidise the Idiocy at Nersa and Escam. Talk about “gaan haal die bobejaan after die berg ne” I am stopping now to further fund the, in my opinion, blatant bribery and corruption. On to my system.  But first some more background.

 

Look at the access to the grid map here:

Now think about all the illegal connections to the grid and non payments (plain corruption and criminal theft) and all the new connections being made daily, both illegal and legal and its impact on your pocket, as we are funding all those illegal connections. I am gatvol for this. Not to even say anything about our own power (utility) independence. If your are dependant for heat in wintertime on Government, imagine how fooked you will be when they cannot deliver power, or worse, deliberately kill your smart meter’s ability to lo load new units….. Just think back a few years when during the holiday period, we could not buy prepaid units at all for a few days, it ended up in Parliment, for what that was worth. Lots of people will do anything to prevent that and do whatever asked, or just plain riot, burn and pillage. Look at our recent experience and that was not even a big event, only the ExPress going to jail.

 

See South Africa on here, our grid breakdown(not currently improving):

Our grid is 34% as Connected but working about half the time and 58% as works most of the time

 

More to follow

….

Sorry for taking this a bit off topic. I think it´s not only SA or Escam that is degenerating, it´s all of the world and the more centralized it gets, the more degenerate it gets.

Just look at the top posts. WHO has a former top communist geurilla and human rights/information suppressor (Tedros), BIS has a mexican control freak (Castens), WEF has a fascist(Schwab) and now they are cronying up togehter. We have a nerd (Bill) who has way more influence on vaccines and conflicting interests, than those who actually know something about vaccines. 

But that´s a rabbit hole.

[Guest Sarel]

On PV wiring and isolation….

For my PC system, I am using Noarc DC 1000V breakers. This is certified for both Isolation and as a circuit breaker (replacing fuses) for DC. Coupled with this there is a Class 1+2 Surge and lightning protector. After that there is a fuse to protect the downstream wiring and equipment, but only in the + side. One thing I dislike is using fuses for disconnecting the PV side. Isolators are designed for that purpose, not fuses.

The DC breaker protects from any mishaps upstream. The code is actually bassacwards in my opinion, in that there is “no required fuses at the panels” to protect downstream cable shorts. Two of my 3 strings will have 700V and the 3rd one 150V. This is high voltages and the energy from a spark or short will be something to behold.

[Guest Sarel]

My identical twin visited again today  3rd phase on the left 

 

and made some mo progress today. What a pain to get the correct house wire  delay upon delay after orders….

Mo Cerbo GX display to be mounted

mo later

[Guest Sarel]

Warning, Danger.  

The +- markings on the Noark DC breakers are wrong. Do NOT follow the making to wire them. The red arrow points to the correct flow indicating how the switch connections are done internally. The wiring colours used in this picture is indeed correct.

[branderplank]

11 minutes ago, Sarel said:

Warning, Danger.  

The +- markings on the Noark DC breakers are wrong. Do NOT follow the making to wire them. The red arrow points to the correct flow indicating how the switch connections are done internally. The wiring colours used in this picture is indeed correct.

Seems like there was a bit of discussion on the wiring of DC CB's in the past:

 

[Guest Sarel]

Indeed, and I am aware of that. These are the 4 pole variants, as you can see and in this case a wiring error will cause a dead short.