Earth Leakage Safety Switch

[101RRS]

My house does not have an Earth Leakage Safety Switch on its powerboard and I want to get one fitted. I know very little about these.

Are these something that has to be fitted by an electrician or do they just plug in on the switch board (like circuit breakers replacing the old fuse blocks)

If to be fitted by an electrician what sort of price are we looking at?

Thanks

Garry

[Mick_Marsh]

They don't just plug in. Get a sparky to do it and he'll supply a safety certificate for the job.
I'll PM a comparitive price to you later.

regards
Mick

[VladTepes]

Its a sparkies job.
best money you'll ever spend.

Saved my wife when she stood on an extension cord that evidently had a short in it. Thing went BANG, the power cut out in a poofteenth flat, and wifes foot was blackened with sooty stuff as was the floor. She lived though.



On second thoughts... how well do you get on with yours.....

[sheerluck]

....On second thoughts... how well do you get on with yours.....

Once you get it done, there'll be no "drop the hairdryer in the bath" trick any more.

Unfortunately my wife has the reflexes of a cat and manages to catch the hairdryer before it hits the water:p

[101RRS]

Got evap air con fitted to the house today and part of the job was to fit earth leakage. I always thought there was just one that covered the whole house but apparently no longer. Now one goes in to replace the circuit breaker on each line - normally the power points. So I got the electrician to also put on the second powerpoint circuit as well. So, I now have earth leakage on the two powerpoint circuits but not lights, water heater, or stove.

I asked why they do not do one to cover the whole house and he indicated that is how it used to be done but no longer - the ones he fitted were the same size as a circuit breaker.

Garry

[Lotz-A-Landies]

Having seperate ELCB is a good thing. It helps you localise and identify the problem appliance without shutting off the rest of the house.

At work we have them on each bedspace, in fact our ED and ICU are cardiac protected a level higher than the ordinary ELCB. You'll have to ask a sparky what the specific differences are, but it means that all our equipment and the areas themselves have to be re-certified each year.

[Mick_Marsh]

Normal ELCB's trip at 30mA detected earth leakage. Hospitals and other selected industrial areas (such as wet areas) trip at 10mA detected earth leakage.
One ELCB for the house was simple for the installer. One active to earth fault detected and the whole house tripped off.
It is much better that each circuit is individually protected so that your viewing of 4WD TV is not interupted when the missis drops the hairdryer into the hand basin.

[sheerluck]

Have to agree that having a separate RCD (ELCB/RCCB call it what you want) helps in the convenience stakes, having the whole house trip because you have a slightly dodgy fridge is a big pain in the whatsits.

[gazk]

I have an earth leakage circuit breaker on each circuit in the house except the HWS and to the sub-board in my shed. A few months back when lightning struck the ground very close nearby it blew the main fuse (80Amp) into the powerboard and tripped the earth leakage CBs. It also did some damage in the shed - scorching a few switches and blowing a fluoro tube apart.
The integral energy guy who replaced the main fuse said that the earth leakage CBs had protected the house appliances from damage. The neighbours weren't so lucky - lots of damaged appliances. He said that he had also seen some circuit breakers blown off powerboards that day.

[Pedro_The_Swift]

there arent many things that will withstand a lightning strike.

1.21 gigawats is a fair bit after all--
https://www.aulro.com/afvb/images/imported/2010/11/1105.jpg

[austastar]

Hi,
we have one ELCB which protects most of the power circuits, but not the lighting, fridge, hot water and a 20A welding power point in the garage.
It can be a pain when yet another iron leaks and blows the ELCB and most of the house goes down. We go through about an iron every 3 years, I have resisted the urge to cut off the earth pin or make an earthless extension cord. for safety reasons.
When the kids were little, I was using the computer in one room just outside the kitchen, the kids were in the kitchen making toast. I heard a sound as the power went off and shot into the kitchen to find the eldest with a steel knife in the toaster hooking out a piece of broken bread.
The ELCB did its job perfectly, he didn't even feel a tingle when he must have touched the live element.
Go for it, put one on each fused circuit.
cheers

[bee utey]

Hi Austastar

The devices are now called RCD's (residual current devices) and trip by comparing the current between the active and neutral. Therefore an earthless extension cord will cause a trip just the same if some of the current goes out through a leak. Just think of double insulated tools, they don't have an earth.

When my sparkie was last at my place he just threw out every individual power-point circuit breaker and installed the new type of RCD breakers. They aren't that dear any more.

[austastar]

Hi bee utey,

I guess mine needs updating at some stage then, it is 24 years old and has 'earth leakage circuit breaker' written on it.
thanks and cheers

[scarry]

And if you happen to have a small A/C inverter split system wired into a circuit with an RCD you will often get nuisance tripping,particularly if it is a Daikin.The larger A/C units should be on their own dedicated circuit so don't have an RCD.

[JA1969]

Hi All,

I'm a sparky and just want to let you know that there are two types of RCD's/ELCB's

The first is just RCD only. These are fairly older units and used to be installed adjacent to the existing fuses/circuit breakers, usually the width of four circuit breakers, and were mainly protecting the power circuits only.

The second type are RCD/MCB. These look exactly the same as your standard circuit breakers but have a built in RCD. Some are the width of two circuit breakers, but newer ones are only one circuit breaker wide. They may also have a small window that changes colour when a fault occurs. This differentiates from a residual current fault or just an overloaded circuit breaker. When you reset the breaker the window clears and is reset.

Some manufacturers make their RCD/MCB work in a way that when there is a fault, the breaker switch will only drop half way. To reset these you just turn the breaker off and back on again.

Individual RCD/MCB are the way to go. You only need to put these on lights, power, garage, pool/spa, etc. They are not needed on stove, hws, a/c circuits.

All new homes will have the lighting circuits protected but it was not necessary to protect these circuits in older homes.

I strongly recommend that the lighting circuits get protected in older homes as well. There was an accident near where I live about 10 years ago, where a young boy was electrocuted when he attempted to climb onto the family metal carport roof to retrieve a ball. When he touched the carport whilst standing on the ladder, his muscles contracted and he couldn't let go. It was later found out that when some backyard wannabe sparky run the wire to the carport light, it was run too close to the roof. At a later date a screw was put through the roof and caught the carport light switch wire (which meant that whenever the carport light was on, the carport was live). A RCD would have saved this boy's life.

Just another point I'd like to make regarding RCD's. It's important to press the test button on these regularly to make sure that they are working properly. Nothing lasts forever and they have been known to fail. I have a RCD tester which tells me the RCD trip time in milliseconds. When I have checked RCD's that have not been tested for a while the trip time has been as high as 45milliseconds. That will kill you! They should trip between 18 and 30 milliseconds.

I apologise for going on about this but I hope this information helps.

Jim

[Bushie]

........................................ I have a RCD tester which tells me the RCD trip time in milliseconds. When I have checked RCD's that have not been tested for a while the trip time has been as high as 45milliseconds. That will kill you! They should trip between 18 and 30 milliseconds.

Jim

When you say haven't been tested for a while, do you mean tested by pressing the test button, or tested by meter/test equipment etc.

My understanding from that would be that if they are not tested by actuation then they may become a bit 'sticky'. Have I got this right ?



Martyn

[JA1969]

That's right Bushie. Test by pushing the test button is all you need to do. Most manufacturers recommend testing monthly.

[Aaron IIA]

Saved my wife when she stood on an extension cord that evidently had a short in it. Thing went BANG, the power cut out in a poofteenth flat, and wifes foot was blackened with sooty stuff as was the floor.

If you got a BANG, a blackened foot and sooty stuff, it is more likely that the fuse/overload circuit breaker is what tripped. A ELCB/RCD will trip too quick to display any of these symptoms. If a short exists between active and neutral, with no earth involved, the ELCB/RCD will not trip.

Aaron.

[101RRS]

Well after 50 years living without a earth leakage switch or the other one it got used the other day - was only fitted just over a month ago.

A friend was over and using his laptop while sitting in my recliner. I was in another room and heard a zap and the power points were all off. I asked what happened and he said that there was a flash in the room and the sound of a zap - he also indicated that his laptop was now on battery. On investigating I found that the 240v power cord to his laptop power supply had been cut to the copper in the wires. He had moved from the recline to situp position in the chair and the metal frame had acted like a pair of scissors and cut through the insulation shorting out the wires.

Thankfully he would not have been electrocuted as the leather and padding would have insulated him from the frame and it seems the earth leakage switch cut to power so quickly that the laptop did not suffer a power surge. On checking the switch board - all circuit breakers were still on and only the earth leakage safety switch had tripped.

So a clear demonstration of how these things work to not only save lives but protect equipment.

Garry

[ozscott]

My house is 15 years old. If my safety switch trips and kills all power in the house except the stove does that mean that it will trip if someone shorts a bayonet fitting out? Ie does the one switch do both lighting and GPO circuits?

Cheers

[rovercare]

My house is 15 years old. If my safety switch trips and kills all power in the house except the stove does that mean that it will trip if someone shorts a bayonet fitting out? Ie does the one switch do both lighting and GPO circuits?

Cheers

If your lights go out when its tripped then yes

[bee utey]

My house is 15 years old. If my safety switch trips and kills all power in the house except the stove does that mean that it will trip if someone shorts a bayonet fitting out? Ie does the one switch do both lighting and GPO circuits?

Cheers
15 years ago my sparkie wired a RCD (safery switch) only to the power points. He said that the fridges/stoves shouldn't be on the same circuit as you would lose your food every time you had a nuisance trip and didn't catch it. He didn't wire the lights as that was not a requirement then. He was just through getting his licence so he had just learnt all the rules.

So in your case I doubt if your lights are on the RCD.

These days you ask a sparkie to come and replace each and every circuit breaker with a separate RCD as they are now the same size. That way you don't lose all of the house at once, and everything is protected.

[rovercare]

15 years ago my sparkie wired a RCD (safery switch) only to the power points. He said that the fridges/stoves shouldn't be on the same circuit as you would lose your food every time you had a nuisance trip and didn't catch it. He didn't wire the lights as that was not a requirement then. He was just through getting his licence so he had just learnt all the rules.

So in your case I doubt if your lights are on the RCD.

These days you ask a sparkie to come and replace each and every circuit breaker with a separate RCD as they are now the same size. That way you don't lose all of the house at once, and everything is protected.


Lights weren't a requirement for a long time, used to be allowed to bang on an RCD to cover the whole house, so dependant on the time it went in will be whether the lights are covered

If the lights go out when the RCD is tripped then they have RCD protection, simple really

Oh, Ovens, Stoves, cook tops, Dedicated A/C, HWS, ccts are never protected as these devices have far to much leakage for a 30mA RCD to not buisance trip

Never would the fridge of been left off the RCD protected power cct, one, that would necessitate seperating the existing power cct and its still a GPO and must be RCD protected

[scarry]

When RCD's first appeared on the market,& before they were mandatory,fridge was left off.This was because most fridges had a lot of heaters in them & would cause nuisance tripping.They were never designed to go on an RCD circuit.

Today things are completely different,all modern fridges(less than 20yrs old approx) are ok on an RCD circuit,any tripping means there is a fault with the cabinet.

As others have also said,all power points must be RCD protected,but some hard wired appliances on their own circuits,such as hot water systems,stoves,ovens,some A/c units,etc,are left off.

[Vern]

can't say i've ever seen an older house where the fridge is wired on its own circuit:(. I do this nowadays (occasionally) and stick it on its own rcd/rcbo:)

[bee utey]

can't say i've ever seen an older house where the fridge is wired on its own circuit:(. I do this nowadays (occasionally) and stick it on its own rcd/rcbo:)
Must have been a short term thing, my previous house wasn't wired that way and the old fridge used to trip the rcd occasionally. Next time the sparkie visits here the breakers will all be upgraded.:)

[George130]

We finally got a mast power switch to the fuse box last year. I never liked not being able to isolate the main board.
At the same time sparkie fitted the seperate power for the AC.

[Aaron IIA]

My house is 15 years old. If my safety switch trips and kills all power in the house except the stove does that mean that it will trip if someone shorts a bayonet fitting out? Ie does the one switch do both lighting and GPO circuits?

Cheers

Don't rely on the "safety switch" to trip if someone shorts a light bayonet fitting. If they are insulated from earth and touch both electrodes of the light, they will get the full 240V. They should survive, as the current will be going directly from one side of the hand to the other. The dangerous shocks are those that go across the chest.

Aaron.

[drivesafe]

Hi folks, I make it a point not to get involved in 240VAC threads because I am NOT an electrician, but have a look at the link below.

One of the companies I deal with is involved with the production of this safety gear and it may be of interest to some on this thread.

:: Protex :: (http://www.protectelec.com.au/pages/index.php)