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Is my DB board wired correctly?


fredhen
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Hi everyone,

We recently moved into a new house that we are renting. When we came to look at the house the current tenants had a changeover switch and second DB board installed that they used with a generator during loadshedding. When we moved in the agent informed us that the electricity is currently not working as the previous tenants took their changeover switch and DB board with them and someone will be coming by to fix the wiring in the DB board.

I opened the DB board to look at how I will wire the ET112 & geyser timer that I'm planning to install and saw that the earth leakage doesn't seem to have a live wire connected to it and testing the switch doesn't trip it like expected.

Here's what it looks like:

712372707_DBWiring.thumb.jpg.4420a7fa1d747104d4edf39b3bcf8f3d.jpg

As I don't generally do more than add a geyser timer or the meter I was planning on installing I don't feel that I know enough to be 100% certain that it is done incorrectly, but should the wiring not look something like this:

1605633624_Throughearthleakage.jpeg.883a60acba4f3ca0772fb3f72e6f34ba.jpeg

As I would prefer it being fixed by an electrician I would like to ask my landlord to get someone out to look at it, so I was just hoping that perhaps someone here with a lot more knowledge like @Jaco de Jongh (who I'm getting the meter from) would be able to tell me what's wrong and if I should get the landlord to get someone out to take a look?

I'm not sure if it's needed as it won't change the DB wiring, but it's a small complex of 5 units running on prepaid electricity and this is the DB for my unit that's in my garage.

Kind regards,
Fred Henning

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11 hours ago, fredhen said:

 

1605633624_Throughearthleakage.jpeg.883a60acba4f3ca0772fb3f72e6f34ba.jpeg

I agree with you. Someone bypassed that RCD. Wired like that, it will never work because it needs a live and neutral supply to operate the electromagnetic switch inside. So your site has no residual current protection, in other words no ground fault protection, which could be life threatening.

My guess would be that the RCD was nuisance tripping and someone simply bypassed it. Or perhaps the RCD failed and they were too cheap to replace it (those CBIs are not cheap, around R750 to R800). Also, I believe the main switch (the one to the left there) should be a double pole, but I'm assuming some things about the earthing arrangement (ie I'm assuming this is not the main connection kiosk in a TN-C-S earthing setup).

The 20A double-pole breaker just to the right of the SPD... maybe that was where they fed in the generator power? So there is no interlocking changeover then. That's at least two SANS violations (can feed the grid, possibly relies on council-side TN bond).

Fixing it should not be too difficult. Toss the 20A double-pole. Install new double-pole 60A main breaker and new RCD. Total parts cost about R1600, plus labour Not your problem... landlord's problem. And he should take that from the tenant's deposit...

Edited by plonkster
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Thank you @plonkster I'll contact the landlord and ask him to get someone out. Is it just luck that everything's been OK for the ~6 months we've been here so far?

1 hour ago, plonkster said:

The 20A double-pole breaker just to the right of the SPD... maybe that was where they fed in the generator power?

The element for the roof mounted solar geyser runs off that 20A double-pole breaker. It's getting its live in from one of the 20A breakers hooked up to the busbar which seemed strange, but I guess that way it also runs through the RCD (if it was connected properly).

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14 minutes ago, fredhen said:

Thank you @plonkster I'll contact the landlord and ask him to get someone out. Is it just luck that everything's been OK for the ~6 months we've been here so far?

I'm going to take a guess here and say that if you got shocked, the earth leakage won't have tripped and you would likely wouldn't have been able to make this post...

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2 hours ago, fredhen said:

just luck

You're running without an earth leakage. As long as nobody touches a live conductor (even by accident) you'll be fine. So luck has something to do with it (or the lack of bad luck rather). If you have young kids in the home, I would advise to have this sorted as soon as possible.

What I also didn't mention is the way it is wired allows you to disconnect the neutral but keep the Live connected. That could have rather interesting effects on some LED lamps, they may for example glow dimly even though they are supposed to be off.

2 hours ago, fredhen said:

The element for the roof mounted solar geyser runs off that 20A double-pole breaker. It's getting its live in from one of the 20A breakers

That's an odd way of doing it. You will have to check with an electrician. Usually you only need to isolate the live connector to a water heater, but there must be an isolator (that interrupts both live and neutral) next to it on the roof. But sometimes the rules change. Either way, you can get rid of one of those breakers. The 20A double-pole one has overcurrent protection (green/white lever) so you essentially have two 20A overcurrent protection breakers in series... one of them can go.

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2 minutes ago, plonkster said:

That could have rather interesting effects on some LED lamps, they may for example glow dimly even though they are supposed to be off.

So that explains it then. Although what is happening is that the larger LED lamps in the bathroom tends to slowly fade over 2-3 seconds after switching it off. Maybe also explain the amount of GU10's that have had to have been replaced.

7 minutes ago, plonkster said:

You will have to check with an electrician.

Yeah, I think I'll just mention that one as well.

2 hours ago, jykenmynie said:

you would likely wouldn't have been able to make this post...

That's not a scary thought at all.

Thanks again everyone. I was hoping to wait until I have the meter to ask the electrician to also wire that for me, but I'm guessing it's better to just do it as soon as possible. At least then I know everything is OK.

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7 minutes ago, fredhen said:

I was hoping to wait until I have the meter

Remember to get minirail to DIN adapters. The ET112 is DIN-mount and won't fit on the Samite rail without the adapter. It needs about 32mm of space in the DB board.

The ET112 has both live connectors on top (neutral at the bottom), which makes it fairly easy to install. You'd normally install it directly after the RCD, before any of the other breakers. The live wire looping around from the RCD then enters the top left of the ET112, and the top right of the ET112 connects directly to the top of the breakers next to it. You could ask the electrician to leave some space (if you have it). Sometimes you can also consolidate circuits into one, for example if a breaker is not very heavily loaded and the wire is sized correctly for that breaker, you can put two downstream circuits on one breaker (if the breaker is 20A, then both cables connecting to it must be rated for 20A, etc). More than two circuits is usually not a good idea, too much risk of a poor connection where three conductors are combined.

If you have to choose between the geyser timer and the ET112... drop the geyser timer. Those things don't save much money regardless of what the sales person told you. They certainly don't pay back the money you spent on them.

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30 minutes ago, plonkster said:

You're running without an earth leakage. As long as nobody touches a live conductor (even by accident) you'll be fine. So luck has something to do with it (or the lack of bad luck rather). If you have young kids in the home, I would advise to have this sorted as soon as possible.

What you happen if he has for example, like I had, some garden lights with a damaged wire? This kept on tripping my EL until I just disconnected those lights completely. Tested with a megger and the cables are stuffed. Can't fix the wires at the moment as these aren't in conduits and are inside a wall... all these interesting things you only realise after the first winter of purchasing a new house...

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5 minutes ago, jykenmynie said:

some garden lights with a damaged wire?

Well, the RCD would not trip. His house would continue to run (and somewhere in the garden it would be slowly heating some water in the soil where it finds its way back to ground). Then one day you'll be digging in the garden or pulling up a weed and you'll strike/touch the damaged cable. Now you're directly touching a live conductor, and it flows across your heart to your feet and you're dead.

If there was an RCD, it would see this 30mA taking a shortcut to earth and it would have tripped, likely saving your life.

My dog was likely saved by an RCD. He likes chewing stuff... anything new introduced into his environment. One rainy winter's morning in August 2013, some people came to put blow-in insulation in my roof, and they plugged an extension cord into an outdoor socket... mmmh new chewy toy... That was the most pitiful yelping I've heard in my life... but he stopped chewing things that are attached to the house after that (he still chews anything you leave lying around, especially PVC plumbing stuff).

Edited by plonkster
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7 minutes ago, plonkster said:

My dog was likely saved by an RCD. He likes chewing stuff... anything new introduced into his environment. One rainy winter's morning in August 2013, some people came to put blow-in insulation in my roof, and they plugged an extension cord into an outdoor socket... mmmh new chewy toy... That was the most pitiful yelping I've heard in my life... but he stopped chewing things that are attached to the house after that (he still chews anything you leave lying around, especially PVC plumbing stuff).

Oh wow! And accident can happen so easily. I became super paranoid about my electricity after joining this forum and trying to learn a bit about it myself...

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32 minutes ago, plonkster said:

Remember to get minirail to DIN adapters.

That's part of the reason why I opened it up as I saw the ET112 only support DIN rails, so I luckily already asked Jaco to add an adapter for me.

32 minutes ago, plonkster said:

You'd normally install it directly after the RCD, before any of the other breakers.

I'm going off topic now, but it's my thread, so I'll allow it. Will it be a problem if it's not wired that way though? As it's not my place and I'll take it with when moving I'd prefer it if it's at the end of the rail along with the geyser timer. I get that the wiring will be a bit more tricky though.

32 minutes ago, plonkster said:

Those things don't save much money regardless of what the sales person told you.

I generally agree with that. The only reason why I got it was that the early morning and late evening showers didn't have enough warm water from sun alone in the winter, so I've only got it just so that it warms up enough in the mornings before the sun takes care of the rest during the day and then top up when the sun goes down.

I've luckily got a long DB board with another 6 slots open at the end and as the timer takes 2 I'm think the meter should fit.

16 minutes ago, jykenmynie said:

I became super paranoid about my electricity after joining this forum and trying to learn a bit about it myself...

Same here. And wow. It's an understatement if I say that I'm pretty stressed out about this now.

Edited by fredhen
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3 hours ago, fredhen said:

I'm going off topic now, but it's my thread, so I'll allow it. Will it be a problem if it's not wired that way though? As it's not my place and I'll take it with when moving I'd prefer it if it's at the end of the rail along with the geyser timer. I get that the wiring will be a bit more tricky though.

It's probably fine to have it at the end. You'll just have a long 6mm wire going all the way across the top to the left-terminal of the ET112, and then you'll have another 6mm red cable coming back from the right-side top terminal of the ET112 to the top of the busbars on the breakers (not that far this time, right to the left of the ET112). Then on the neutral side, according to the ET112 manual, you're supposed to put a fused connection to the neutral busbar, but you can leave the fuse it with the proviso that this must also be 6mm cable then. Reason for using this oversized cable on the neutral side (even though it only carries the current of the ET112 itself, which is mere MILLIAMPS), is that the cable must always be sized for the upstream breaker, which in this case is the main 63A incoming breaker.

It wasn't clear to me that there is space on the right, I was working this entire time under the assumption that (like most people) you don't have enough space to even fit an opinion nevermind a breaker... 🙂

Also, I deliberately put the ET112 after the RCD in this scenario because 1) it does not really matter if you put it before or after, and 2) that allows you to tie the neutral of the ET112 to the neutral busbar post-RCD, which is just so much easier.

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2 hours ago, plonkster said:

6mm wire

Is 6mm fine? I was under the impression that I'll need to use 16mm or at least 10mm.

2 hours ago, plonkster said:

you're supposed to put a fused connection to the neutral busbar, but you can leave the fuse it with the proviso that this must also be 6mm cable then.

I was actually going to start a thread about the fuse being required according to the documentation on Victron's site, but got so preoccupied with this db wiring that I forgot about it. Thank you for answering that!

I was pleasantly surprised when I walked in and saw the row blanks on the board considering the amount of breakers already in there.

2 hours ago, plonkster said:

it does not really matter if you put it before or after

Even if there is something like a oven or geyser in front of it and not connecting through it. I'm guessing it'll pick everything up then and not just what is flowing through it? (It's not relevant now as everything is going through the RCD, but just thinking about it for future)

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9 hours ago, fredhen said:

Even if there is something like a oven or geyser in front of it and not connecting through it

All items before the output of the meter will not be part of you measurement. 

So if you just want to measure some items and exclude other like the stove to see your consumption before you spec and install your system then that is fine. 
When you install the system you will want to move the meter to measure everything. The difference between that measurement and your inverter output is what those excluded items use, and this can then be seen in the graphs. (if you are going with a Multiplus II for instance you could put all the excluded items on the output 2 and it will be included in the Multi's measurement, but that is then also limited to what that output is rated for)

So keeping in mind that you might want to change to position of your meter in future, it might be easier to install it where Plonkster suggested (or not)

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10 hours ago, fredhen said:

Is 6mm fine? I was under the impression that I'll need to use 16mm or at least 10mm.

You're right, for the full 60 you'll need 10mm^2. 6 is going to be a little short.

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Thanks for the help on this everyone.

Had an electrician over this afternoon who quickly wired the RCD correctly and found an issue on one of the plug circuits that would have caused the RCD to trip, quickly tested some plugs and found one where the cover's screw was making contact causing it to short, fixed that and now I can start to relax.

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Wow, that 'quick fix' by the previous owner could have gotten someone killed.

 I just thought I would share this (slightly) related story here.  In 2013 I had a blown fuse in my Toyota Tazz, which I had bought new in 2003. This was the first time since it was bought that I had needed to open the fuse box. I then discovered that the fuse for the cabin fan had melted/merged into the surrounding plastic of the fuse box (but surprisingly this was not the one that had blown). Upon closer inspection I saw that it was a higher rated fuse than that which was supposed to have been fitted there.  I replaced it with a fuse of the correct rating, and tested the fan. It promptly blew the fuse when the fan exceeded setting 1. I tried it again and blew another fuse. I had a hunch that it was probably the 'quick fix' work of the person that had fitted the alarm just after I bought it 10 years ago. I never had it fixed, I just fitted the correct fuse and knew not to put the fan on 2, haha.  Luckily the car was stolen a couple of months later, so it became someone else's problem!

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4 hours ago, fredhen said:

Thanks for the help on this everyone.

Had an electrician over this afternoon who quickly wired the RCD correctly and found an issue on one of the plug circuits that would have caused the RCD to trip, quickly tested some plugs and found one where the cover's screw was making contact causing it to short, fixed that and now I can start to relax.

Was one of the screws inside the plug turned through the live wire? Did the plug have a plastic cover plate?

This is incredible...

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14 hours ago, jykenmynie said:

Was one of the screws inside the plug turned through the live wire? Did the plug have a plastic cover plate?

I'm not 100% sure, but I actually believe that was the case. He did show it to me, but it was dark and I was just anxious to get everything working again :)
Yes, the plugs have plastic cover plates.

On 2020/07/21 at 7:01 AM, Louisvdw said:

All items before the output of the meter will not be part of you measurement. 

I've had a look at it again and everything is after the RCD, so with the RCD now actually working I can simply wire it like @plonkster mentioned.

 

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18 hours ago, jykenmynie said:

Was one of the screws inside the plug turned through the live wire?

Pretty typical issue. Whatever sharp screw is handy is used to mount the plastic plate to the box. Drywall screws for example... and then sometimes that shart point will pierce one of the conductors causing an earth fault. Now if it pierces a live conductor, then usually the breaker trips, or if it is a small leak and the RCD trips, then the problem usually goes away if you turn off the breaker to that circuit. So that kind of fault can be found through a process of elimination by the home owner.

BUT... if it pierces a neutral, then the earth leakage trips, and you have NO easy way to find it. You have to isolate the lives and the neutrals in the DB board until you find the one that trips the RCD. An inexperienced DIY homeowner/handyman might conclude that there is something wrong with the RCD... and bypass it.

I have my own love/hate relationship with RCDs and modern appliances. Specifically, every $*@#% modern appliance now has a surge arrestor and/or EMI filter, and those things pass current to the earth wire. Small amounts. It is known as the standing loss, and most IT people know about it (too many computers on a circuit, and the RCD starts tripping). So this is how things are in my house right now re standing loss:

leakage.jpeg.2859b1ce197e7e1c0bb3ce99ca0364db.jpeg

Now the rules state that 1) you must have a 30mA RCD on plugs, 2) it MUST trip on 30mA residual current , 3) it MAY trip from 15mA onwards. As you can see... sort of surfing on the edge there. But it gets worse. When the inverter's bonding relay opens/closes, I get:

leakage2.jpeg.a03e99961702b3780c690c6aa3a318d5.jpeg

Now I have a very expensive RCD installed that is transient resistant, so it does not trip at this level... but if I add one more appliance (the laser printer we bought to home school the kids during COVID19)... it starts tripping every time the power comes back after load shedding.

So now I have to split my essentials into two groups with their own RCDs, so I can get the standing leakage down below 10mA again.

 

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23 minutes ago, plonkster said:

You have to isolate the lives and the neutrals in the DB board until you find the one that trips the RCD.

I believe this was the case here as the electrician disconnected the neutrals from the busbar to find the one causing a leak between with the earth. After that he managed to easily find the live and determine the breaker that it's connected to and confirmed it as being the cause by switching everything except that one on and keeping the neutral disconnected from the busbar.
Then the plug tester came out to determine which plugs are linked to it, but when I walked into the house I could hear the small inverter for the home office still running off battery power, so they tested the plugs in that area and found 3 that are on the breaker and opened them up to find the one causing the problem.

 

30 minutes ago, plonkster said:

it starts tripping every time the power comes back after load shedding.

 

31 minutes ago, plonkster said:

So now I have to split my essentials into two groups with their own RCDs

That must be a pain.

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12 hours ago, Ric Cup said:

If you have a double pole SPN 60A mains.

Does your geyser need to go through a 20A double pole SPN Breaker...?

And should that be connected to the earth leakage?

Kind regards

Geyser must be protected by Earth leakage.  Geyser and water pipes must also me earth bonded

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