Earth Leakage Breaker (RCD) Tripping

[Houses4Rent]

Question: My electrician said:

"It is optional to have the lights and/or geyser on ELU but also not a must. This is normally left at the discretion of the tenant/owner."

Is that correct and not regulated at all?

[Dave A]

It is optional to have the lights and/or geyser on ELU but also not a must.

Correct, with some conditions attached.

For example, if there is a ceiling fan on the light circuit, the fan must either have an isolator within arms reach, or the light circuit must be on earth leakage. (See 6.16.1.4 of SANS 10142-1)

When it comes to fixed appliances (including geysers & luminaires) in zone 1 or zone 2 in a bathroom, if it is not a class II appliance it has to be on earth leakage. (See Table 7.1 of SANS 10142-1 )

[DieterT]

Question: My electrician said:

"It is optional to have the lights and/or geyser on ELU but also not a must. This is normally left at the discretion of the tenant/owner."

Is that correct and not regulated at all?

If I was the tenant/owner and the electrician said to me

"It is optional to have the lights and/or geyser on ELU but also not a must. This is normally left at the discretion of the tenant/owner."

I would tell him to get the out!

Of course it is regulated. Conditions has to be met as mentioned. Some parts of the installation has to be under earth leakage and some parts not, should it meet the required conditions.
Nowhere ever was a choice ever given to the tenant/owner what has and does not have to be under earth leakage.
Maybe it could be that he found the lights and geyser to be effectively earthed and thus primary protection is adhered to and then only he could recommend to you in order to avoid nuisance tripping to have them removed from earth leakage or recommend for extra protection and to avoid nuisance tripping to have multiple ELUs in the DB board. If this is not the case then this electrician is "besig om n lat vir sy gat te pluk" and I hope for every job he does for you that he gives you a CoC

I have seen this way too many times. Earth leakage tripping, get to the house and find everything is wired under earth leakage (most of the time because it was some MnT job and they do so to cover themselves)
Sparky then goes and rewires the DB so it's just the plugs under earth leakage and the rest above....you ask what is wrong with this picture? The sparky never gone to check the primary form of protection. In effect taking secondary form of protection away, there is no more protection. But you say I can see the earth connected to the appliance/geyser/lights, but is it really, is the earth resistance such that should a fault occur and you are touching the conductive surface that, that fault condition will dissipate to earth via the earth connection, or through you as person to earth? and or is the earth resistance as such should a fault occur the circuit breaker would trip (yes a poor earth influences the CB from tripping as per designed curve)

Did the sparky check that before rewiring the DB in order to stop the nuisance tripping? I tell you most probably not, cause most of them can't even get it right on the CoC.
Do yourself a favour and watch next time someone does a CoC if they are testing the earth resistance from incoming earth to each point of consumption and conductive surfaces for earth continuity and earth resistance.

[Houses4Rent]

Thanks, that is all a bit too high for laymen like me. The EL tripped without any apparent reason. That is when sparky removed lights from EL.

"We took the lights off from earth leakage which could be the cause of the power tripping. The hot water cylinder was not on Earth leakage. "

[AndyD]

Thanks, that is all a bit too high for laymen like me. The EL tripped without any apparent reason. That is when sparky removed lights from EL.

"We took the lights off from earth leakage which could be the cause of the power tripping. The hot water cylinder was not on Earth leakage. "

I would personally say a circuit should not be removed from the earth leakage for 2 reasons;
Firstly the level of protection on that circuit has been reduced to overload only meaning it's now less safe than it was originally.
Secondly if it's causing the earth leakage to trip then there's nearly always a fault that needs actually finding and remedying rather than a half-assed workaround.

The earth leakage offers a fair to good level of fire protection, if there's a poor termination that's overheating or burning or some kind of arcing fault the earth leakage will almost always by the protective device that trips long in advanced of the 10A or 20A circuit breaker. Removing circuits from the earth leakage breaker because of a tripping problem is something I'd expect from a DIY'er but I hold electricians to higher standards and hope it's something they wouldn't do regardless of whether the regs specifically forbid it or not. The regs are the absolute minimum permissible standard and not to be considered pinnacle of electrical good practice.

The fact is however that probably in the majority of cases that a circuit is removed from the RCD because it's causing tripping it would be against the regs because the circuit itself or the fixed appliance has a fault or intermittent fault such as low insulation which would be below the allowed value stated in the regs.

There's many options available other than removing a circuit from an earth leakage breaker such as;

• Find the fault.
• Redesign the circuit if there's high standing/functional leakage.
• Find the damn fault.
• Install an RCBO for that circuit.
• Install a second RCD an split the DB circuits accordingly.
• Did I mention find the fault?

Earth leakage faults are often caused by;

1. Rodent damage.
2. Insect infestation.
3. Water ingress
4. Physical damage or excessive wear and tear to cables or a part of an appliance.
5. Poor terminations or other types of arcing faults.

In all of these cases just removing the circuit from the earth leakage is asking for trouble.

[Leecatt]

I agree, so many times I have found that the earth leakage is tripping due to BURNING WIRES inside of a light fitting or connection box. Removing the light circuit from the earth leakage does not resolve the problem, it exacerbates it.

[Brett Nortje]

I agree, so many times I have found that the earth leakage is tripping due to BURNING WIRES inside of a light fitting or connection box. Removing the light circuit from the earth leakage does not resolve the problem, it exacerbates it.

The only reason those wires are burning is because there is 'too much heat per capita,' or, not enough area for electrons. think, now, if you were to have heat 'enveloping an area,' the more area there is, the more the heat spreads - like a hot spring where there is much more heat than a kettle, yet, there is so much less steam, yes?

If you really know your stuff, you might want to make fancy wires! these wires could be made out of something denser, or, a better conductor. you could make money with the people that take care of their stuff, but builders will always use the cheapest stuff.

[AndyD]

Most of the burning connections or terminations I come across are plain old poor installation techniques. It's little things like not using end ferrules on fine stranded wires when terminating, incorrectly sized connector blocks, too many wires in a termination, wires that are twisted too tight and they don't spread in the MCB cage clamp, even wires that have completely missed the cage clamp on MCB's and were just trapped behind it. Poor crimping technique on lugs is another....... the number of times I see lugs crimped using a pair of side cutters or hammer and screwdriver, I swear there must be a nationwide shortage of indent crimpers, oh yeah and over-tightened screws in plugs is another.

Poor installation technique still remains the most common cause of burning or arcing problems I come across but poor quality manufacturing is more recently becoming a serious contender for the title. Neutral bars with only a single screw per termination are quite common to see failures on, in the good old days where there were double screwed connections failures were pretty rare. Poor clamp terminals on MCB's are more common nowadays as well, I've come across a few MCB's in the last year or two where no matter how the wire is inserted it doesn't get firmly clamped by the termination, either that or the screws strip....and before someone suggests it, yes I do use a calibrated torque driver for wiring up panels.

[Justloadit]

The screws strip or the thread strips because they have reduced the thickness of the termination material, so that they can save a few cents. Thinner material means there is less area to cut the thread on.

Another issue I have found, especially with high current terminations, and areas in which there are high swings in temperature, is that the terminal screw unloosens, or more likely is that the copper in time with the high current flow, changes shape, aggravated by the pressure of the screw force on the copper. Over time the electrical contact degrades, whcih cause more temperature due to contact resistance, and the copper becomes annealed, and the start of a burning point.

Part of maintenance in panels is to check the terminations points every 6 months to ensure that they remain tight.

[AndyD]

Yep the copper settles over time but if the wire was correctly prepared it's usually minimised. It's a habit of some to use linesman's pliers to twist the wire strands tight before putting the wire into the lug or cage clamp or if there's two wires they twist both wires together tightly. This just means the wires don't settle into the shape of the clamp as it's tightened and the contact area between the clamp and the wire is a lot less..... leading to higher resistance...... leading to heat.

Molex have a nice beginners guide to crimping, it's biased toward production line crimping but it's an interesting read and good info.

[Justloadit]

The issue is rather the electrician in most instances. How perfectionist is he, or is he simply trying to make a quick buck.

I love tools, and in many instances, I have tools which I may only use once or twice a year.The fact remains, that when I have used that tool, I am confident that what I have done will stand the test of time.I am a believer of doing your best at what ever I do, even if it is digging a hole in the garden. I like to get the right tool for the job.

[AndyD]

Tools are important especially with processes like crimping, there's no substitute for using the correct crimper for the type and size of crimp you're using. I think your first point might be even more important though, the attitude of the person doing the work invariably reflects heavily on the quality of the finished job. I also used to think shoddy workmanship was about people trying to make a 'quick buck', I'm sure that's the motivation for some of the corner cutting I encounter almost daily but over the years I've started leaning more toward thinking it's a general personality deficit and simply a lack of pride or concern.

Maybe in the past there was an education angle as well, bad habits like old wives tales or urban myths get passed on from generation to generation. I know a few of the things I was taught by the journeymen and masters who were my mentors when I was an apprentice were not the best practices. In those days you just did what you were taught and there were very few ways to improve or verify your inherited knowledge but nowadays with the internet there's no excuse for not constantly checking and learning and keeping your knowledge accurate and up to date.

[jkamuz]

Just a quick question, is the use of porcelain screw connectors compliant. I prefer crimped joints.

Sent from my GT-I9100 using Tapatalk

[AndyD]

They're most commonly used internally in appliances like stoves, autoclaves, kilns and ovens where there's high temperatures. As far as I know there's nothing in the regs that would mean you can't use them but they wouldn't be the best or most appropriate connector for most applications.

[Dave A]

Just a quick question, is the use of porcelain screw connectors compliant. I prefer crimped joints.

per SANS 10142-1
It's definitely not compliant with SANS 10142-1 for earth connections (a joint must require a tool to disconnect). When it comes to phase and neutral conductors, it is cable type dependant as I recall.