20 hours ago, viceroy said:

The diagram raises one more question for me though. In my Inverter DB, I have a main breaker before the inverter. Looks like I should add another main breaker (Sub main Switch) after the EL?

Can that sub main switch be housed in the inverter DB or must it sit in the main DB before the essential loads breakers? If it needs to be housed in the main DB, I'm stuffed as there is no more room

I follow the same pattern on the output of the inverter as you would normally follow for a distribution board. The DB is arranged from left to right. Electricity from the inverter enters from the top left, and it leaves on the bottom right from the various breakers for each circuit. On the very left (first in line) goes a double-pole main switch with overcurrent protection (Hager makes a nice single-space double-pole breaker if space is an issue). Next comes an RCD. And then follows the breakers for the circuits.

On the diagram above the main switch and the RCD is swapped for some reason. Technically it doesn't matter which way round you put them, I just prefer that it mirrors a normal (sub?) distribution board.

There are other tricks you can use if space is limited. You can use an RCBO (a combination overcurrent/RCD). I speak under correction, but I suspect the reason why it shows both a "main switch" and an RCD (or EL if you will) is that RCDs generally don't have overcurrent protection, only residual-current protection. You need both, so whatever you need to get both, that is what you must do.

Thanks for the reply @plonkster, very interesting about the RCBO. I wasn't aware they existed.

I had a bit of an "Aha" moment last night while lying in bed. Rather than have the essential load breakers in the main DB, and have to try make space, I'll just use a larger Inverter DB, most likely a dual 12 way, and move those breakers there.

Keep the top row as is, but move the RCD down to the bottom row with a main breaker as well as breakers for each load.
I like this idea as it removes the individual breakers from the main DB, actually creating space, and I can split each load onto its own breaker, whereas currently I have up to 3 loads per breaker.

Spent some time today in the DB board, the aim being to identify which neutrals went with which circuits for when split them out to the inverter DB board.

Before

* please note the bottom left corner, is a somewhat melted.connector I'll get back to that.

During

* please notice the now taped up connector in the middle of the DB board. This little bastard gave my fingers a tingle, even though the house is disconnected from the grid at the edge of the property, and no alternative power supplies are currently installed.

After

Not much different, but everything is labelled, vacuumed, neutral identified ready to be split, essential load lives ready to be taken to the inverter DB board, and dodgy breakers replaced.

But, that little bastard that I mentioned before...it had power, even though the house was disconnected from the grid, and I don't like that.
The little block it was connected with was melted, so something is amiss. It also passes through the DB board, not connecting to anything except neutral.
I've replaced the melted connector with a beefier one too, and taped up.

I'm going to have it checked out, but for the time being any ideas?

 

Oh, I also got this.

Edited January 11, 20206 yr by viceroy
Added comment.

4 hours ago, viceroy said:

Spent some time today in the DB board

Hi Viceroy, well done on the DB so far, big step to go that far. My board used to look allot like yours but I than decided to fit a bigger board because of the splitting of circuits and normally you end up adding extra cb’s for critical and non essential loads. The old rule of thumb with DB’s is when your done there must be about 30% spare space in the DB. This is not always possible but for a electrician this makes life easy around a DB and changing a thing or two for a COC becomes a pleasure.

You could of also fitted a big DB like a (12 x 3row) that is relative cheap about R450 at AC/DC over the existing DB. That would sort you should you need to add extras  later.

 

 

Thanks for commenting @Gerrie.

I won't go as far as changing out this DB for a bigger one, reason being is I'll be moving the last 3 breakers from the right hand side (Plugs and 2x Lights) to a separate DB board on the other side of the wall which will house all of the essential circuits, while this DB will only house breakers for non-essential circuits. I will also change the MAINS breaker to a double which can disconnect neutral and live together, rather than just disconnecting live as it does now. Not sure how legal it is at the moment, but I suspect it was done when they fitted the second geyser.

Anyway, I'm done with the main DB board for now. Fixed the daisy chain, replaced with a 63A busbar, and most of the breakers are now the same (couldn't fit the busbar with the mixture of Majortech and ABB breakers, so just populated all with what I have.)

Also started moving the PV wiring from the garage side of the house over to where the inverter is installed.

I used heatshrink tubes to Id all the wires. Helped to have a schoolteacher wife 🙂

On 2020/01/12 at 8:09 PM, viceroy said:

I will also change the MAINS breaker to a double which can disconnect neutral and live together, rather than just disconnecting live as it does now. Not sure how legal it is at the moment, but I suspect it was done when they fitted the second geyser.

I don’t know how your wiring will be but I think you will need a extra Earth leakage for your essentials on that essential DB unless it is somehow wired to work all from the one earth leakage.

I had to go for a bigger DB (12x3way) on my installation when I done the splitting, because I ended up installing a lot more.

1. hager change over switch for manual operation

2. Two change over contactors for automatic operation

3. One 2-chanel sonoff switch

4. Extra earth leakage for essentials.

5. About 8 x Extra cb’s to accommodate more circuits and controls

6. To still do indication lights.

7. To still add more surge protection

I should of even installed a bigger sized DB but at the time the 3way seemed big enough, I still have a bit space but is now sitting on about 92% full 🧐

10 hours ago, Gerrie said:

I don’t know how your wiring will be but I think you will need a extra Earth leakage for your essentials on that essential DB unless it is somehow wired to work all from the one earth leakage.

I had to go for a bigger DB (12x3way) on my installation when I done the splitting, because I ended up installing a lot more.

1. hager change over switch for manual operation

2. Two change over contactors for automatic operation

3. One 2-chanel sonoff switch

4. Extra earth leakage for essentials.

5. About 8 x Extra cb’s to accommodate more circuits and controls

6. To still do indication lights.

7. To still add more surge protection

I should of even installed a bigger sized DB but at the time the 3way seemed big enough, I still have a bit space but is now sitting on about 92% full 🧐

Pic of your board?

Edited January 19, 20206 yr by Shockin

56 minutes ago, Shockin said:

Pic of your board?

I went for a flush mount DB and keypad, because this is all in my main bedroom.

 

On ‎2020‎/‎01‎/‎18 at 8:41 PM, Gerrie said:

I don’t know how your wiring will be but I think you will need a extra Earth leakage for your essentials on that essential DB unless it is somehow wired to work all from the one earth leakage.

I'll be using a common earth for both DB boards, only the neutral will be split. --edit. Just reread your comment. I do have an additional earth leakage for the essential loads.

I wired up the essentials DB yesterday, still to be connected to the main DB, and currently I have 28% capacity shared between the boards, so I think I'm good.

I like the flush mount, but for now the essentials DB is surface mounted, saving costs and whatnot.

Project next year is most likely to flushmount, and combine everything into one DB board.

Edited January 20, 20206 yr by viceroy

Surface mount dB adds a lot of space for wires. 

Now that I'm about ready to wire the new DB to the existing main, I have questions for any indicator lights I need to install.

1) Are there any colours that I should stick to? I've been seeing red for grid, and blue for generator in some change over switches. Are yellow and green also acceptable?

2) I'm assuming I connecting the lights to the source, before any breakers in order to show the source is live, and not just the source selected?

You need to label everything anyhow. 

Just go for small led lights. They all tend to be too bright. 

4 hours ago, viceroy said:

1) Are there any colours that I should stick to? I've been seeing red for grid, and blue for generator in some change over switches. Are yellow and green also acceptable?

2) I'm assuming I connecting the lights to the source, before any breakers in order to show the source is live, and not just the source selected?

1. You can use any color as you need to label them anyway.   

2. I don’t think there is a problem connecting them before the source, but according to me its better to have the light on that is supplying the power at that time. If you have both supplies feeding at one time like essential might be on inverter and non-essential on grid than both indicators should be one. Than you also need a warning label indicating Alternative supply on DB.

Still a bunch to do/redo, but a slight miscommunication on Friday afternoon kinda forced me to get my ass into gear.

Got home from fetching the kids from school and found out we had no power. This was a surprise as there was no load shedding scheduled, but through January there have been numerous substation trips, so I figured it was that. In a frantic panic to get the house, or part of the house powered before the wife got home (she's been on my case about finishing this project), I began feeding wires through the wall, connecting things up to the second DB and inverter, and trying to finish up before it got dark.

Needless to say the cause of our outage was a lack of credits in the pre-paid meter.🙈

The end result was an almost working system. In my rush, I'd done something wrong and turning the downstairs lights would trip the EL. Turning on the main geyser would trip the sub-main db board EL. It was dark, I was annoyed, so the lights and the geyser stayed off that night.

Saturday morning, I got up early determined to sort out whatever I'd messed up. I was pretty sure it was Neutral related, but wasn't quite sure what yet. I had two suspicions though. Either one of the circuits was bonded to the wrong neutral bus (Each DB has a separate neutral from the other) or how I was connecting neutral in the main db to the inverter was wrong.

I chose to concentrate on the latter assumption as if I was right, it required the least work to fix. I was wrong and every alternate way I tried of taking neutral to the sub main db resulted in a worse trip scenario.

Turned out I had connected the downstairs lights and geyser to the wrong neutrals...took a while to trace, but all is now working 100% as expected. I also worked out that the strange wire going through the DB without connecting to anything other than neutral (see previous post where I asked about it) is related to the geyser. Apparently, or so I've been told, it's something to with Eskom turning off your geyser when they like.

Anyway, still to do:

1 ) blanking plate for main DB.
2 ) trunking between battery and inverter.
3 ) end cap for trunking at inverter.
4 ) warning labels, and proper db board labels coming soon
5 ) finish ICC Pi install, and not just sat on battery box.
6 ) surge arrester for PV.
7 ) replace PV cutoff switch (only large enough for 6mm cable, so for now I've had to limit PV charging to less than 40A)
8 ) install indicator lights in db board.
9 ) anything I've forgotten to mention here

And finally some progress pics.

5 hours ago, viceroy said:

I also worked out that the strange wire going through the DB without connecting to anything other than neutral (see previous post where I asked about it) is related to the geyser. Apparently, or so I've been told, it's something to with Eskom turning off your geyser when they like.

Yup, the ripple switch has 4 terminals. Two powers the device itself, and the other two switches the power to the geyser. They are not fed via the same breaker. The idea is that I can turn the geyser off at the breaker, but the ripple switch remains on and can receive signals from the grid.

If you don't do it this way, and the ripple is sent while you have things turned off, you will miss the signal, the wife will have a cold shower, and your life will suck.

In my house the ripple switch was wired wrong. Did not have a separate supply line. Then came the solar geyser in 2011, and shortly after a timer, and around that time I bypassed the ripple switch as it caused too much trouble.

 

Where does one add these indicator lights, are they required by SANS or are they a nice to have?

Are they 220 or 12volt LED's?

23 hours ago, FixAMess said:

Where does one add these indicator lights, are they required by SANS or are they a nice to have?

Are they 220 or 12volt LED's?

I think they are a nice to have, and not required by SANS.

They are 220V.

@viceroy you have done a lot of work yourself and it really looks neat and tidy. Well done.

Thank you @Wilfred.

This has been a constant learning experience for me, and something I'm enjoying doing.

On 2020/01/09 at 1:29 PM, viceroy said:

Yes, but the fuse is only on positive. I just replicated what the solar installer did previously.

Please excuse the messy cables. All will be shortened and tidied once I have the trunking in place.

@viceroy Did you ever get a comprehensive answer regarding your single Fuse on the positive battery cable? (between the battery and inverter)

I have installed a 100Amp DC fuse in a single disconnect holder on the positive cable, but No Fuse on the negative wire in my system.

Rather than just getting a "yes you do" or "no you don't", I'd rather understand the principal behind it.

The more I ask the more different answers I am getting!

1 hour ago, John G said:

@viceroy Did you ever get a comprehensive answer regarding your single Fuse on the positive battery cable?

About the most comprehensive answer I got was along the lines of:

The negative has the same potential as the positive, and even with the positive disconnected, its possible to have current flow through the negative (in a problem situation), so better to fuse both than just the one.

While I haven't done it just yet, I am going to install my second fuse onto the negative cable. Rather safe than sorry.

Thanks @viceroy for the feedback. That makes more sense than a lot of the other explanations I have heard. I am meeting an installer over the weekend who specializes in industrial solar installs, see what his take is on this and let you know.

 

On 2020/02/04 at 1:23 PM, viceroy said:

The negative has the same potential as the positive, and even with the positive disconnected, its possible to have current flow through the negative (in a problem situation), so better to fuse both than just the one.

Ground faults. In floating systems (where neither side is tied to the chasis or to earth), the first ground fault goes unnoticed, and the second one causes a fault current and needs to be protected. Since battery systems are typically left floating, that would apply here.

To make this a bit more practical, think of the typical automotive layout. Negative is securely tied to the chassis of the vehicle. Any fault (aka short circuit or high current flow) from a higher potential can be protected against by fusing the positive wire. So only one fuse needed.

Now imagine the same vehicle, but without the negative ground, and imagine a ground fault where a positive wire touches the chassis. This goes unnoticed, because the circuit is not complete, but should a second fault develop on the negative side, the circuit would be complete and a large fault current will flow unless there is a fuse to protect against this.

Because neither side is explicitly tied to the chassis, both sides are fused to protect against such faults.

If you design the system so that a ground fault is unlikely, for example by placing the fuse close to the battery or even on it, I maintain that double-fusing is not needed.

Load current (or if you like fault current) originates from a battery terminal and returns to the other battery terminal.

Any single break in this circuit will prevent current flow.