# Interest group forums > Electrical Contracting Industry Forum >  Does a stove need to be on an earth leakage?

## Leecatt

Something that I often come across is a stove that has been removed from the earth leakage in domestic installations.
Many electricians believe that a stove does not need to be protected by an earth leakage and this may not be the case.
Where a stove is supplied via a stove coupler then the need for an earth leakage falls away, however, in the absence of a stove coupler then the stove must be supplied via an earth leakage.
Here is a very interesting article on this subject

http://www.eepublishers.co.za/articl...ppliances.html

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## Dave A

> Where a stove is supplied via a stove coupler then the need for an earth leakage falls away, however, in the absence of a stove coupler then the stove must be supplied via an earth leakage.


My understanding is the stove may also be without earth leakage protection when it's a fixed wire installation and there isn't a socket outlet  :Confused:

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## Leecatt

> My understanding is the stove may also be without earth leakage protection when it's a fixed wire installation and there isn't a socket outlet


Me too Dave. The only reason I researched this was the new requirement for plug socket outlets in SANS. I decided to find out what a 164-1/2/3/4/...plug socket outlet looked like and came across this bit about the stove coupler.
We learn every day hey?

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## ians

This is rather interesting, considering i am yet to see a stove coupler in any stove connection in durban or surrounding areas.

The way i do the inspection report, if there is a socket outlet in the switch disconnector on the wall with a 16 amp fuse, it must be on earth leakage, if the stove is connected via a 45 amp isolator with no socket outlet, no earth leakage is required. If there is no earth leakeage and a socket on the isolator, i take super glue and glue one of those baby cover into the socket, so that you cannot take it out and remove the fuse.

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## Leecatt

> This is rather interesting, considering i am yet to see a stove coupler in any stove connection in durban or surrounding areas.
> 
> The way i do the inspection report, if there is a socket outlet in the switch disconnector on the wall with a 16 amp fuse, it must be on earth leakage, if the stove is connected via a 45 amp isolator with no socket outlet, no earth leakage is required. If there is no earth leakeage and a socket on the isolator, i take super glue and glue one of those baby cover into the socket, so that you cannot take it out and remove the fuse.


I think that there are stove couplers in places like company canteens.
The standards are not very flexible in this area and i will remember this in future.
With regards to fuses in socket outlets I would remove that I think. Despite the reference to the "original standards applicable during erection", it is more often than not that the fuse wire is replaced with fencing wire.

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## ians

Never seen one, not in company canteens, commercial centres, industrial enviroments, nowhere.

Dave have your guys in working in Durban ever seen a stove coupler installed, while carrying out inspection reports in KZN?

I have heard they are big in the Cape.

The scary thing is that people in KZN take their stoves when they move, unles sit is a built in HOB or undercounter unit.

Apparently many years ago a 2 year old child electricuted to death in a house in Westville, the previous owner disconnected the stove and left the wires, live, sticking out the sprag, new owners moved in child went into the kitchen. The house was inspected and passed, but the owner disconnected the stove when he moved out.

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## Dave A

> Dave have your guys in working in Durban ever seen a stove coupler installed, while carrying out inspection reports in KZN?


Yep - we've seen a few. I'm not sure I could extract stats on numbers, though. Apparently it's ridiculous how much it forces the stove away from the wall...

I've got a sneaking suspicion it's supposed to be positioned at the side of the space allocated to the free standing stove instead of the middle of the space. It'll certainly make a big difference - but I guess old habits die hard.

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## Sparks

Far as I know the isolators with socket outlets are no longer available. I actually hunted far and wide for fuses so that I could install one,which I had removed elsewhere, at my folks place. The socket outlet is used every day and is very conveniently situated. Having 40A available in the kitchen is great for large appliances. As for the stove causing nuisance tripping, well, since installing the isolator with socket outlet, more than 10 years ago, the stove has not tripped the ELCB once. The socket outlet is obviously rated higher than 16A. The unit has a seperate isolating switch for the socket outlet as well as the "cooker". Both are switched off at night.

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## Katenda

The latest stoves do not have fuses and if it is fed from a 45 amp Circuit Breaker the person using the stove when a fault occur will get a massive surprise! Maybe that is why most guys place it on E/L?

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## JFK

Seriously!!! The reason so-called _'competent'_ electricians remove a stove from the Earthleakage is to prevent it from tripping. The REASON why it trips IS because there IS current leaking on the stove which CAN electrocute someone!!! This means the stove is UNSAFE and a HAZARD!!! This is NOT nuisance tripping issue but an ACTUAL electrical PROBLEM!!!

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## kosmonooit

Having just tried to memorise SANS 10142, I can confirm

6.7.5.5 The following do not need earth leakage protection:

.. 

d) a stove coupler that complies with SANS 60309-1/IEC 60309-1 and of
dimensions as given in SANS 337 (see 6.15.1.2.5). Amdt 5


What exactly this makes in terms of nullifying the need for protection I cant say.

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## DieterT

So in saying all this in this discussion about removing stoves and lights from earth leakage protection, who of you actually do the earth resistance test and continuity of bonding before doing this?
Just remember that the earth leakage is not the primary form of protection, its an added protection.

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## Didditmiself

Precisely! The only reason anybody would decide to remove an earth leakage CB is because of it being a nuisance. :Confused:  If it trips, then better to look for the fault.

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## DieterT

> Precisely! The only reason anybody would decide to remove an earth leakage CB is because of it being a nuisance. If it trips, then better to look for the fault.


Or in the case of an new installation one would design the installation as such to only have socket outlets under earth leakage protection (also other devices which could require E/L protection), also only after satisfying oneself that the earth resistance of the earth continuity conductor is within the required earth resistance limit in accordance to the protective device. Therefor also avoiding nuisance tripping of the earth leakage, but still offering the primary form of protection on all electrical devices and continuity of all conductive surfaces which could become live in the case of malfunction of electrical devices or wiring.

I prefer to have everything under E/L, but that is my preference and not the industry requirement and with saying that it will not just be one earth leakage. I would install a separate earth leakage for my plugs and at each sub board it's own (swimming pool/garage/ etc.) I cannot enforce my own preferences onto my client, it is a "nice to have" and extra form of protection which is not required. With larger developments this would for sure make the cost difference an enormous amount. Normally one can see especially with larger developments who the the inexperienced electricians are due to the fact that everything is wired underneath earth leakage, because having everything under E/L means then the sparky can get aways with doing a poor job...

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## JFK

Forget what SANS says for a minute, and let's break this down... The stove trips the earth leakage; electrician removes the stove circuit from the earth leakage; earth leakage doesn't trip any more; problem solved, right? Can any proper qualified electrician honestly tell me that he'll go home and NOT worry WHY the stove caused the E/L to trip in the 1st place, plus now he's just removed an essential SAFETY device from the stove circuit?

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## kosmonooit

As long at the external conductive surfaces are earthed on a stove, isn't that the major safety base covered? just asking ...

Also still wondering why you don't have a stove on EL if that specific plug/socket is used as per the regs? Why would that change anything to do with safety as far as EL / Residual Current is concerned?

Can't see any point in putting lights on EL, but if it makes one or the client feel safer, then why not, but using multiple units per sub circuit might make this less trouble.

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## AndyD

> As long at the external conductive surfaces are earthed on a stove, isn't that the major safety base covered? just asking ...


People getting electric shocks is an extremely serious matter because a few milliamps traveling though some poor soul can cause their death. Electrical installations have a belt and braces approach to stopping people getting shocked. For someone to get shocked under normal circumstances requires that there's two serious faults happening simultaneously and either of these faults must, according to the regs, be repaired immediately upon being discovered. 

Firstly we have the earth wiring which should prevent the chassis of any item or appliance from becoming at a voltage that can give someone a shock (touch voltage). There's a few problems with this, corrosion, poor connections and terminations, trailing cable damage and even missing connections often make the earthing inadequate or even ineffective. Add to this the fact that when it's tested by an electrician the tester being used actually passes a few miliamps through it during the test; even the best tester will only use a few Amps whereas under fault condition the earth wiring may need to carry hundreds or even thousands of Amps momentarily and invariably that's when any weaknesses show themselves. As soon as a single earth is missing or inadequate, the surrounding equipotential zone that was providing user safety then becomes your worst enemy.

Under normal conditions a missing or inadequate earth won't cause injury, it does however mean that if there's another fault on the same circuit it can be lethal.  

Secondly we have insulation. This is the medium that separates the current carrying parts of the circuit from the other parts of the installation that can be touched by a user. It ensures that current stays withing the circuit and doesn't 'leak' out and find it's way to earth through unauthorized paths. Failure of the insulation and the potentially dangerous condition it can cause would be detected firstly by the earth leakage breaker which would usually trip when around 25(ish) miliamps is leaking. If there's a complete failure of the insulation then a much larger current will flow which will cause the normal circuit breaker that's supplying that particular circuit to trip. This only protects the circuit wiring from overload, it won't protect someone who gets a massive shock, they'll be long dead by the time a 10 or 20A circuit breaker has disconnected by tripping. Insulation faults are also deemed by the regs to require immediate remedy.

As with the earth fault, an insulation fault on its own won't cause injury or give a shock because the earth is preventing the faulty item developing a 'touch voltage'.

So no single fault will cause a shock but ignoring an insulation fault puts all the eggs in one basket leaving the earth as the only protection. Not acceptable. A circuit tripping an earth leakage breaker and being removed from the earth leakage protection...not acceptable.

Don't treat the symptoms, treat the actual cause. Find the damn fault and fix it.  






> Also still wondering why you don't have a stove on EL if that specific plug/socket is used as per the regs? Why would that change anything to do with safety as far as EL / Residual Current is concerned?
> 
> Can't see any point in putting lights on EL, but if it makes one or the client feel safer, then why not, but using multiple units per sub circuit might make this less trouble.


 I'd suggest nowadays we should actually be using domestic DB's with dual e/leakage protection as a minimum with one E/L for the sockets and one for the remainder of the installation. There's no reason not to, the cost has reduced to such a point where it's no longer an issue and using two E/L breakers gives a safer installation without the annoyance of the entire power going off every time there's tripping. We should in fact be using RCBO's giving earth leakage protection on every single circuit individually but whilst they've been the norm overseas link1 link2 link3 link4 for the last few years they don't even sell them in any of the major SA wholesalers yet  :Frown: .

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## Didditmiself

Andy, what are RCBO's? Maybe someone else mentioned it but I missed it.

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## AndyD

An RCBO is similar to a normal circuit breaker but it also provides 30mA earth leakage protection as well as the standard overload protection on a circuit by circuit basis.

The average domestic installation has a single earth leakage breaker that protects the entire installation which introduces a few problems. For example a single earth leakage fault on only one of the circuits causes the entire installation to trip in most cases which certainly isn't ideal. Also many electronic appliances have an acceptable amount of background earth leakage during their normal operation. This background leakage can accumulate to a substantial amount if there's several PC's, TV's and fluorescent lights or LED drivers being supplied and it can cause annoyance tripping of the earth leakage breaker even though there's not actually a fault present.

Using RCBO's means that every individual circuit has it's own 30mA earth leakage protection so if there's an earth leakage fault on any one circuit, only that circuit trips.

This is a single pole RCBO, it only interrupts the live of the circuit, the neutral connection you can see is just for reference. 



The problem with just interrupting the neutral with an earth leakage fault is that whilst the circuit will become dead the fault won't actually be cleared if it's N-E leakage. That's why it's better to use the type below which is 2-pole, it disconnects the live and the neutral together if there's a fault. (It's actually an SP+N type circuit breaker because it only provides overload protection monitoring on the live wire, not the neutral.)

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CLIVE-TRIANGLE (27-Aug-15), Didditmiself (26-Aug-15)

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## Justloadit

I arrived recently from an overseas trip, and took note of the DB in the apartment I used. Interestingly, in this 2 bedroom apartment, two toilet, and lounge,  there was 8 RCBO's separating lights in rooms, plugs in rooms, appliances.  Each circuit breaker was numbered, and a table on the door indicated exactly what each circuit breaker was protecting. Any laymen by identifying the tripped breaker number would immediately be able to identify the fault location.

On second thought, I should have taken a picture when I looked.

I thionk we got a long way to go to follow this route. In my mind this is the way it should be done.

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## AndyD

That's pretty much the way we label as well. We number each circuit breaker and we provide a card in the door of the DB which states the current and curve of the breaker and exactly what each one is protecting. We keep a pdf copy of every legend card we make so we can easily provide a replacement if the original grows legs. Also we label the individual sockets, isolators and light switches with the number of the circuit breaker that supplies them. 

The worst labeling I come across is usually in domestic premises, there seems to be a trend of just calling each circuit breaker either 'plugs' or 'lights' which isn't much use when there's numerous socket and light circuits. Also the adhesive labels should be outlawed, they always come adrift over time. All labeling should be traffolyte in my opinion.

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## kosmonooit

The requirements for labelling are quite clear in the regs, each circuit should be identified but it really depends on the effort & care that the installer is prepared to put in. Most of the time I see those stickers you get on sheets that just say "Plugs" "Lights" as you say but I agree indexing them to  circuit descriptions, a sheet in the back of the db cover is a good idea, or even printed longer labels on the cover. For other labelling I use a Brother printer, it produces a durable label, perhaps in commercial installations when one has the means and the time to engrave labels, that would preferable.

What I do see often is the popular bad habit is gluing cut plastic sheet to cover gaps between circuit breakers, that definitely does not stand the test of time and falls of in a few years.

"Best Practices" ... seems lacking in the industry. And lets no go to what one sees in ceilings  :Embarrassment:

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AndyD (27-Aug-15)

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## Justloadit

Nice way Andy.

My current house has no door, but a crappy cover over the circuit breakers. The 2 screws holding the cover have stripped the thread from the DB side, so everything stands scew and at an angle. Over the years I have labelled a few of the circuit breakers, such as the geysers, out buildings and pool pump. Fortunately it is in the garage, so no one sees it. But darn what a crappy way of doing things.

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AndyD (27-Aug-15)

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## ians

Just a note, a brand new stove plate out the box can trip an earth due to moisture. Stoves connected to earth leakage units are an expensive waste of time. Make sure earth is up to standard and you can go home and sleep without worrying.

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AndyD (27-Aug-15)

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## ians

Having light circuits on earth leakage is another silly idea. Earth leakage trips, now you have to try find a torch or phone etc. The new south Africa load shedding has resolved this issue to an extent. How ever introduced a new pile of problems generator connections, inverters and solar power.

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## AndyD

> ........What I do see often is the popular bad habit is gluing cut plastic sheet to cover gaps between circuit breakers, that definitely does not stand the test of time and falls of in a few years.
> 
> "Best Practices" ... seems lacking in the industry. And lets no go to what one sees in ceilings


 I don't think it's possible to compensate for shoddy workmanship with legislation. You can make as many rules and regs as you like, if a tradesman has no care and pride in their work you're always going to end up with a shoddy job outcome.




> Nice way Andy.
> 
> My current house has no door, but a crappy cover over the circuit breakers. The 2 screws holding the cover have stripped the thread from the DB side, so everything stands scew and at an angle. Over the years I have labelled a few of the circuit breakers, such as the geysers, out buildings and pool pump. Fortunately it is in the garage, so no one sees it. But darn what a crappy way of doing things.


 Some labels is always better than no labels but it should have been fully labelled when it was installed and also if the property has ever changed hands the labelling would need to be complete for the CoC to be issued.

Domestic DB's are notorious for stripped screws, they just have about two turns of thread in a piece of 0.9mm plate. We usually use a clinchnut tool (sometimes called rivnut) to put proper thread inserts in, it looks a bit like a pop riveter and it inserts a proper threaded bush that will never strip. You get a nice small portable version like this which will work up to an 8mm thread and it won't break the bank. We have also use a fancy hydraulic one in the workshop that can insert up to 12mm threads.

 




> Having light circuits on earth leakage is another silly idea. Earth leakage trips, now you have to try find a torch or phone etc. The new south Africa load shedding has resolved this issue to an extent. How ever introduced a new pile of problems generator connections, inverters and solar power.


 I think if a light circuit is on an RCBO it will only trip if there's a good and proper leakage fault on that actual circuit in which case it's a good thing to have it trip even if it is an inconvenience. You're right though if there's a single upfront earth leakage breaker for the entire installation it is a right royal pain if there's a tripping problem somewhere else that's causing the lights to go off as well.

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Dave A (27-Aug-15), Justloadit (28-Aug-15)

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## Justloadit

> Having light circuits on earth leakage is another silly idea. Earth leakage trips, now you have to try find a torch or phone etc.


One concern I have about the lights not being on a ELB, is when the glass part of an E28 screw globe comes unstuck from the base, and when you turn breaks off. Now one needs to get a long nose pliers to dig and catch the metal base to unscrew. I am always concerned that the wall switch, actually switches off the Live circuit. When this happens I do switch off the main switch for safety, but what about other people? I suppose with the new LED and CFL versions this may not happen.

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## AndyD

I think lighting, especially in domestic installations should be considered high shock risk. Light fittings are often replaced as fashion accessories by DIY'ers so poor terminations and missing CPC's are likely as well as DIY relocations where the entire fitting gets moved and the cabling extended. Light fittings have notoriously poor cable strain relief and it's not uncommon to see the screw in lamp holders connected the wrong way around where the body of the lamp cap (threaded part) is live and the center pin is neutral. Also as Justloadit says many people rely on the single pole light switch for safe isolation....which it isn't. There's numerous other reasons I'd consider them high risk including the fact that many cheaper electrical testers can't give a reliable voltage reading if the circuit is live and supplied by a dimmer.

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## ians

When the lamp breaks, you shouldnt be messing with a long nose pliers in it unless you have isolated the system.

We cant start fitting earth units to everything because people negligent. Then we might as well enforce a law that machine in factories should all be on earth leakage.

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## ians

This why it is so important that a real electrician carries out the work and a qualified tester does the testing properly.

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## Justloadit

Agreed Ian, however one can not ignore being safety conscientious when dealing with people who have no clue what electricity is, and because they can not see it, they do not understand the dangers and risk involved.

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## AndyD

I'm also a firm believer you can't compile regs around trying to combat against user stupidity or abuse, but, I'm also not against improving the safety and user friendliness of an installation by installing RCBO's on every circuit, including lighting, stoves and geysers if they're a sensible option and reasonably priced.

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## Dave A

A past partner in my electrical contracting company had a theory that one of the reasons light circuits could be off earth leakage was that if you happened to get a shock while changing a light bulb, you're virtually guaranteed to break connection with the source of the shock.




> I'm also a firm believer you can't compile regs around trying to combat against user stupidity or abuse, but, I'm also not against improving the safety and user friendliness of an installation by installing RCBO's on every circuit, including lighting, stoves and geysers if they're a sensible option and reasonably priced.


Hard to argue with great common sense - so I'm not even going to try  :Smile:

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## Justloadit

> A past partner in my electrical contracting company had a theory that one of the reasons light circuits could be off earth leakage was that if you happened to get a shock while changing a light bulb, you're virtually guaranteed to break connection with the source of the shock.
> 
> 
> Hard to argue with great common sense - so I'm not even going to try


It all depends on how high you are on a ladder.

A friend of mine, who manufacturers large transformers, a few years back was helping someone with his electric fence, and in the process shocked himself, fell  off the ladder and landed on his head. Unfortunately he is now paralyzed and sits in a wheel chair.

If this had been a a typical installation with an earth leakage, then there would have been no shock and no disastrous accident

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## AndyD

Working at heights is another reason lighting should be considered high risk. It's true that any shock would possibly be a high resistance one via footwear, the step ladders and down the earth through the flooring, there's not usually much else in the vicinity that would be part of the equipotential zone unless you're unlucky enough to be holding the earthed body of the fitting whilst contacting the elevated voltage..

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## Dave A

Even if on earth leakage, you'll still get enough of a jolt to have some people falling off their ladder, folks  :Stick Out Tongue: 

The solution to that hazard would be to insist on SELV or PELV only.

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## ians

The power shouldnt be on while working on a light fitting or any electrical for that matter. That is why we have circuit isolation/ lock out. A cowboy working on a live circuit shouldnt justify a standard adjustment, ie earth leakage just for a fool. The cowboys ahould be be charged for negligence if he doesnt die from his shocking experience 😏

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## Justloadit

Ians I hear you, but let me cite an example here.

Divorced mother with a 13 or 15 year old son, living in an apartment, and the lounge light pops. She asks her son to replace the globe. So he switches the light switch off, and climbs on a chair/table to replace the E28 globe. As he turns it, the glass breaks off from the base. He needs to change the globe because it is dark. Trusting that the electrician wired the place correctly, he would attempt to remove the base......... or does the divorced mother call in an electrician at R500 to replace the globe?

Does not make sense.

A lay person is under the impression that qualified artisans worked on the apartment when it was constructed, as should be the case.

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## ians

Ok...so the council should put the entire grid on earth leakage, but why. Anyone walked around squatter camps. Extension cords hanging from poles. More people die from illegal connections than people changing light bulbs. In fact exposed wiring at street light poles and CDU's which are accessible to toddlers never mind a 13 year old are very common sight.

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## ians

As it is common knowledge not to walk in the right hand of a freeway, so is the fact that electricity is dangerous. Thats why we have a law which makes the main switch accessible, less than 2.2 m and it isolates "both" live and neutral.

For the record how many people have died from electrocution changing a light bulb?

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## Justloadit

> For the record how many people have died from electrocution changing a light bulb?


Just shows you how well the ELB is  :Smile: 

Jokes aside, the illegal connections are what they are illegal, and if some one gets electrocuted, they do not blame the sparky for it or the municipality/ESKOM

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## ians

As with the example using the 15 year old, how does a 5 year old know the difference between a loose illegal wire left exposed on the ground and certified one.

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## Justloadit

Responsibility lays with the parent/property owner.
If the said property is constructed under legal specifications, one would assume that the hired artisan is actually qualified in the respective trade, and not pretending to be when accepting payment an issuing certificates.
On the other hand, a shack, to start off with does not fall under any building regulations, and any electrical connection made would fall outside the COC as it could never be a legal structure in the first place.

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## phillyza

Our oven is tripping the earth leakage. This doesn't happen immediately, but only after a while, while the oven is warming up. Yesterday I did a test and switch off all other circuit breakers except the mains, earth leakage and the oven. Just to eliminate other influences. Switched on the oven to 180 degrees. After a few minutes, it tripped earth leakage. Reset the breaker and after few minutes, tripped again. It reached the temperature, I put in muffins in the oven, baked it for 30 minutes, and it didn't trip again. 

I had an electrician out at our place and explained to him what happens and he suggested (without testing anything) just to buy a new oven. He indicated that it can be the switch or the thermostat or the element and we can replace one by one but we might still have the problem and its just easier to replace the oven. 

No I need a second opinion as the 2x tripping while warming up don't really justify getting a new oven, unless I'm wrong? I understand the problem is that somewhere in the circuit there is current leaking and can cause electrical shock, but can't this be traced to the exact component causing the problem?

Your assistance would appreciated.

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## Lionels

It sound to me that the element is what is causing the tripping of the earth leakage.
Depending on what type of oven it is, it could be either the bake or the grill element, but it is normally the bake element on the bottom of the oven.

With the element expanding and contracting through usage, the element shroud gets hairline cracks it it and moisture enters the element, when heating up the trapped moisture causes an earth fault, but after a while, because the element gets hot the and the crack opens up, because of expansion, the moisture can escape, thus the tripping problem stops.

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AndyD (06-Dec-16), ians (05-Dec-16), phillyza (07-Dec-16)

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## DieterT

What Lionels said.

That electrician you got sounds to be very lazy.
There is a thing we call fault finding. It's tripping so lets go and find out the origin of the problem.
Look if your oven is broken, old and looks the part to be replaced, then by all means do so. I would look firstly at the elements, those who tend to get a bit of moisture / splatter from baking & cooking. Do insulation tests on them and move on from there. It could even be the supply cable to the oven that is the problem.

We had a client which complained that as soon as they used the iron the earth leakage would trip.
So they replaced the iron. About 4 irons later, each more expensive than the last, they asked that we come to separate the circuits on the house cause with original installation they wired everything underneath earth leakage. So creating a essential side and non-essential side, everything still under earth leakage, the iron tripped a earth leakage again. Luckily not the rest of the house, fridge/freezer etc. cause of the separation.

So we went to do fault finding and eventually after making sure nothing is plugged in and having done an insulation resistance test, found there was a problem on the circuit. We then disconnected all the plug sockets and found that the one where the iron was plugged into had moisture in the back, possibly damp rising (and the rest of the sockets on the same outside wall) Luckily the wire supplying the circuit was fine.
So yes, you might change the oven, but the problem could also be with the rest of the circuit feeding the oven. Good place to start, the elements and then work your way back to the origin of the supply.

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AndyD (06-Dec-16), phillyza (07-Dec-16)

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## AndyD

> ...Yesterday I did a test and switch off all other circuit breakers except the mains, earth leakage and the oven. Just to eliminate other influences.


 This wouldn't eliminate all other influences unless the circuit breakers are double pole (SP+N). 





> I had an electrician out at our place and explained to him what happens and he suggested (without testing anything) just to buy a new oven. He indicated that it can be the switch or the thermostat or the element and we can replace one by one but we might still have the problem and its just easier to replace the oven.


 Not sure why he wouldn't do some tests to localise the fault and prove the supply circuit is okay. He's not done his job so I hope he didn't charge you.

Yes, the fault could lie with any of the components mentioned but it's highly unlikely. The most likely candidate by far is the actual element but some basic testing would be the way to go before blindly replacing parts or the entire oven without knowing for sure where the fault is.




> No I need a second opinion as the 2x tripping while warming up don't really justify getting a new oven, unless I'm wrong? I understand the problem is that somewhere in the circuit there is current leaking and can cause electrical shock, but can't this be traced to the exact component causing the problem?
> 
> Your assistance would appreciated.


 Yes it can be traced by any competent sparky who isn't in such a rush or so lazy he doesn't want to run some tests.

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phillyza (07-Dec-16)

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## Ndzondie

Do i need to connect my stove from protected neutral or from unprotected and why?

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## Sparks

The stove circuit is not required by law to have a protected supply. Provided you have a good earth connection it is safe to disconnect it from the earth leakage. I would however suggest you rather determine which element is faulty and just replace that one yourself. Because the fault is in all likelihood a hairline crack as already explained you can determine which one is faulty by process of elimination. Switching them on one by one. If your oven has preheat it will switch on more than one element so do not use that setting.

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## hislordship

Here is an interesting situation for you.
My oven bake element started tripping earlier this year. Bake element. I got the replacement and fitted it. Worked for a while and started tripping again. But only randomly. Not every time. Plus when it trips it will work immediately again and only trip later.

I thought it must be the top bake/grill combination one this time.
Did some testing by disconnecting and running them etc. Turns out it is the bake one again, hardly used.

But during my testing I tried running the oven off an extension cable from my garage DB (3 phase E/L 30mA) and it never tripped.
House DB was the old Heinemann 3 phase 20mA sensitivity type.

There was also one week here where the whole neighbourhood was on low voltage (220v down to 200v over the normal 240v to 230v range, fault was eventually found to be Brightwater Commons when the whole area blacked out one night). During this time the oven didn't trip the house E/L once.

So knowing the E/L was old I changed it yesterday to a new 3 phase 30mA one. More for safety than for the oven issue (it wasn't always disconnecting all phases when it tripped).
Oven still tripping the house board last night. Got the extension out and back to garage DB and it was fine.
Tested voltage at oven terminals on house board. 240v.
On different phase from garage board the voltage over the extension dropped to 220v at oven terminals.

So this morning some more tests.
Removed oven earth and tested earth to oven chassis voltage when hot. 115v. Touched earth wire to oven chassis and trip.

I tried a hard wiring to the garage board with a temp cable.
Finally the garage board tripped!

It seems the element will work fine as long as the voltage goes no higher than 220v!
But it is definitely faulty so must be changed AGAIN this year.

Just posting this for your interest because it is such a strange turn of events.

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## AndyD

> ............But during my testing I tried running the oven off an extension cable from my garage DB (3 phase E/L 30mA) and it never tripped.
> House DB was the old Heinemann 3 phase 20mA sensitivity type.


Is the house DB the main DB? Is the 3-phase earth leakage breaker the 'main breaker'?





> So this morning some more tests.
> Removed oven earth and tested earth to oven chassis voltage when hot. 115v. Touched earth wire to oven chassis and trip.


If you've got a known tripping fault on an appliance why would you disconnect the earth wire then put power on it and attempt to do live tests? This is dangerous. On top of that the tests you were doing are not relevant and their results are likely to be misleading. Firstly with a stove or oven there's highly likely to be parallel paths to earth, secondly the voltage you measured would be highly likely to vary wildly depending on the input resistance of the particular voltmeter you're using.

If you suspect you've got a faulty element why don't you just disconnect and IR test the element with a mega tester at 500v? You can't accurately localise a fault by using the earth leakage breaker instead of the correct test equipment, you're just going to run yourself around in circles...... I can state with a high degree of certainty that if there's an earth leakage fault on an element it won't make any difference to the likelihood of the earth leakage breaker tripping if the supply voltage is 220v or if it's 240v.

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Dave A (18-Dec-17)

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## Sparks

IR test is the only way to say as Andy said, but not just the oven element. The oven itself could have a wire causing it, it could also be one of the stove plates, depending on the switches as there is a common neutral throughout the appliance.

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## hislordship

I posted my findings not for the benefit of being told how to do or not do something.
I may not be a registered electrician, but my knowledge of electricity and wiring standards is far better than what I have seen done.
I have 24 years of experience with electricity, so I know my TT from my TN-C-S (and missing neutral issues), my single phase from my three phase, my cable sizing etc. Heck, I told City Power about the voltage issue I described a week before the actual fault showed up. I told them to check their transformers etc for the cause.


In answer to the questions:

The house and the garage DBs are independent of each other. Wiring runs as follows (large property):

METER DB FEED TO MAIN DB (NEXT TO METER DB AT THE SIDE OF HOUSE)

MAIN DB [NO E/L] FEEDS
(1) SWIMMING POOL DB
(2) HOUSE DB
(3) GARAGE DB
(4) BURGLAR ALARM FLOODLIGHT SYSTEM [ONLY SINGLE PHASE BOARD]
[1-4 ABOVE ARE E/L BOARDS]

(1) FEEDS ADDITIONAL WORKSHOP D/B
(2) FEEDS ENTERTAINMENT ROOM DB AND BOREHOLE DB
(3) FEEDS STAFF ROOM DB


My use of removing the earth was to confirm 100% that the element is faulty which it has, *and also to try to find why it would trip at certain voltages and not others.*
I don't possess an insulation tester, as mentioned I am not an electrician as occupation.

The stove doesn't trip when using any of the plates, the warmer drawer or when using the grill option (top of oven, dual element).
Only the normal bake oven trips the power. So it must be either the new bottom bake element or the smaller of the two on the top element (around 20 years old).

As stated, the element doesn't trip consistently, so difficult to run it to see which on trips. Hence disconnecting the earth wire. This showed up the leakage to the chassis. On disconnecting the bottom element, the leakage disappeared. 
PROBLEM SOLVED (also eliminates the top element as there was now NO leakage with it still connected).

I forgot to mention, on switching the oven on (without earth), the leakage shows up immediately, but at a much lower voltage (8v or so). it gradually rises as the element heats (obvious). BUT touching the earth to the chassis causes no trip 90% of the time, even when reading 115v chassis to earth. I tried touching it back 10 times, and only once did it trip. Did this mostly out of curiousity.

Yes removing the earth is not recommended, but I can tell you that the appliance was still on earth leakage, and also that no on else was allowed near the thing, even pets. I am very careful, excessively so. There was no risk to me at any point. No touching the chassis, no touching any of the wires directly.


*Regardless of what you think, I can guarantee you the element NEVER trips at 220v or below. Any voltages above that and it will start tripping. If you don't believe me, you are welcome to the element to conduct tests.* Collect from me in Randburg.

Why I posted this in the first place? To let everyone know that such an odd situation can arise. Not to find the problem. I've done that.
Also not to be sermonised on my methodology.
Remember, I didn't correct your incorrect use of *it's (abbreviation of it is) vs its (possessive) and there's (there is) when you mean there are, i.e. as a plural*.

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## AndyD

> .....Why I posted this in the first place? To let everyone know that such an odd situation can arise. Not to find the problem. I've done that.
> Also not to be sermonised on my methodology.


I'm afraid we're going to have to agree to disagree on several points here and I can understand why you might see it that you're a victim of sermonising or your competence is being questioned but that isn't my objective. 

The problem I had was that you've posted your fault finding endeavours as a fait accomplis and as something of a tutorial or reference for future readers on a public forum. The tests you've done are inconclusive but far more importantly, the minute you disconnected the earth wire and made the appliance live, they crossed the line and bacame dangerous. On a personal level I can't and never will be able to walk on by and not offer what I'd hope is a balanced reply to highlight hazardous practices and deter future casual visitors to the forum from believing that this may be acceptable practice and from doing the same.




> *My use of removing the earth was to confirm 100% that the element is faulty* which it has, *and also to try to find why it would trip at certain voltages and not others.*
> I don't possess an insulation tester, as mentioned I am not an electrician as occupation.
> 
> The stove doesn't trip when using any of the plates, the warmer drawer or when using the grill option (top of oven, dual element).
> Only the normal bake oven trips the power. So it must be either the new bottom bake element or the smaller of the two on the top element (around 20 years old).
> 
> As stated, the element doesn't trip consistently, *so difficult to run it to see which on trips. Hence disconnecting the earth wire.* This showed up the leakage to the chassis. On disconnecting the bottom element, the leakage disappeared. 
> PROBLEM SOLVED (also eliminates the top element as there was now NO leakage with it still connected).
> 
> ...


In this post I've quoted you've spent the majority of it justifying a method of testing that is blatently dangerous and should never be done under any circumstances. *There is no justification*. '_Careful_' isn't enough  ....even someone who is trained and has the appropriate experience and equipment to work live would still identify and assess the risks for every stage of every job and then have a pre planned strategy for effectively managing them.

You've also reinforced a common misconception when you imply above that working live isn't so bad because there was still an earth leakage breaker to protect you. If you understood how an earth leakage circuit breaker works you'd know how dangerous that assumption is. It's not the first time I've seen statements like that so I'm going to give you some facts;


The electrical supply is 50 Hz which means there's 50 complete cycles per second.Each cycle has full voltage twice, once in the positive and once in the negative hence the voltage is at its full value 100 times per second (every 10 milliseconds).An earth leakage circuit breaker is considered fully functional if it trips in 200 milliseconds for a 30mA fault.An earth leakage circuit breaker is considered fully functional if it trips in 40 milliseconds for a 150mA fault.An earth leakage circuit breaker is considered fully functional if it trips in 40 milliseconds for any leakage fault greater than 150mA. 
Earth leakage circuit breakers are great for detecting potentially dangerous faults and disconnecting the circuit *before* someone gets a shock by tripping.
If you're the only path to earth because you've disconnected the earth wire and you've made direct contact with something that's live then a massive fault current can flow through you for 40 miliseconds meaning you get a full voltage shock 4 times before the earth leakage disconnects....and that's assuming it's working correctly. There's a very high likelihood of serious injury or death. Earth leakage breakers are only considered as *supplementary* protection (not primary protection) in the electrical regs for good reason.


*Working on live circuits or appliances is unacceptably risky even for experienced electricians, disconnecting the earth wire first and then working live is even worse, downright reckless in fact.
Please don't do it, ever.*

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## Festi

Good day

I have a strange stove EL problem. When using a certain plate on the stove, we tend to set it to max and turn it down once the cooking temp is reached.
From time to time when 'switching down', it trips the EL. Max is '9', this trip happens even if the switch is set to 8.

A good few years ago I had the same issue in another house, when I had an electrician out he said the stove earth did not need to go through the EL and made the changes. As far as I knew at the time, the stove was still earthed, just not through the EL.

Am I sitting in the same situation?

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## Festi

Just a bit more info - when the switch is on '9', the switch clicks, and clicks again when setting to '8'.

Problem does seem to be more prevalent when any other plate is also on. although not always the case.

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## AndyD

Is it the spiral type or the solid heating plates?

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## Festi

Morning Andy

Solid plates. switches turn like a volume control - click to start, smooth up to 8, then click onto 9. It's when turning from 9 down that the ELS trips. so from the MAX click.

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## AndyD

It's a bit odd, I thought the stoves with spiral plates had the type of temperature controller you describe and the stoves with solid plates click between every different setting. Also, don't the solid plate controls only have 5 or 6 temperature settings?

Can you attach a photo please?

Maybe one of the domestic sparkies can give you better info than me, it's not the kind of thing I usually work on so I'm not so familiar with it.

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## Festi

Thanks Andy

I did speak to Sparky, he suggested there could be a fault with the plate/s. I do not suspect the EL, this was replaced already, was very finicky when we had bad weather. After speaking to another electrician about this issue he suggested I get the EL changed then, the brand was a very fong kong type.

The stove we have is an AEG hob, all 4 plates work the same way - 0 clicks and then smooth up to 8, clicking to 9 (max) and then clicking when turning back to 8 and lower.

Switch are located on the oven.

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## AndyD

There's a good chance from the fault you describe that one or more of the plates has a fault that's causing the earth leakage to trip. Problem is that to prove it you need the right test equipment which is outside the budget of most DIY'ers so you're going to have to get a sparky in to do the testing unless you just want to chance that a replacement plate might fix the problem.

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## Sparks

> It's a bit odd, I thought the stoves with spiral plates had the type of temperature controller you describe and the stoves with solid plates click between every different setting. Also, don't the solid plate controls only have 5 or 6 temperature settings?
> 
> Can you attach a photo please?
> 
> Maybe one of the domestic sparkies can give you better info than me, it's not the kind of thing I usually work on so I'm not so familiar with it.


I agree Andy. Enegy regulators are usually used on spiral plates which is why my 1st thought was that the switch is perhaps arcing causing the intermittent tripping. I have given a list of possible faults which can all be tested for with an insulation tester. One cannot pinpoint the cause without actually testing the stove.

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## Festi

Thanks for the thoughts guys. My suspicions are that it is the 1 plate arcing. ( the heat controller ). The tripping only happens when this plate is on, and when turning it down from MAX.

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## Sparks

Be sure to get the correct switch. I suspect that the wrong type of switch has been used.

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