Leakage

[m4tty]

Hi,

What appliances in domestic houses are most likely to have earth leakage causing an RCD to trip?

Apart from Washing Machine, Tumble, Dishwasher, Fridge Freezer, Microwave

Thanks

 

[Badger]

Hi,What appliances in domestic houses are most likely to have earth leakage causing an RCD to trip?

Apart from Washing Machine, Tumble, Dishwasher, Fridge Freezer, Microwave

Thanks

PC (computers) , Kettle, Toaster, Heaters (Fan type)

 

[Revved Up Sparky]

Hi,What appliances in domestic houses are most likely to have earth leakage causing an RCD to trip?

Apart from Washing Machine, Tumble, Dishwasher, Fridge Freezer, Microwave

Thanks

In my experience, any inductive load (Def: An electrical load which pulls a large amount of current (an inrush current) when first energized. After a few cycles or seconds the current "settles down" to the full-load running current) is probably more likely to cause an RCD to trip. Most recently I was called to a house with a tripping problem and it was caused by a faulty waste disposal unit.

 

[sparkytim]

I have also had problem with double pole switched sockets tripping RCD when switching Off!

Replaced with single pole standard type and solved problem

Other causes can be transient vloltages on supply, common problem on overhead supplies with dicky joint on pole

If lights fliker on windy nights good sign of problems up pole

Get DNO in check it out.

RCDs 30 m A nightmares!

 

[batty]

I have also had problem with double pole switched sockets tripping RCD when switching Off!Replaced with single pole standard type and solved problem

Other causes can be transient vloltages on supply, common problem on overhead supplies with dicky joint on pole

If lights fliker on windy nights good sign of problems up pole

Get DNO in check it out.

RCDs 30 m A nightmares!

I don't understand the double pole switching thing that just does not make sense to me.

 

[revjames]

cookers and old fridges...

 

[ADS]

I don't understand the double pole switching thing that just does not make sense to me.

That's about the only thing in this thread that is making sense to me

Line and Neutral could be being cut at slightly different times (might only be milliseconds apart) and the RCD is sensing the imbalance.

headbang Ha Ha, Scrap That!! I've just realised what I said. Once line or neutral are cut there won't be any current flow to be 'imbalanced' (if thats a word) headbang

.

.

Hi,Apart from Washing Machine, Tumble, Dishwasher, Fridge Freezer, Microwave

Thanks

PC (computers) , Kettle, Toaster, Heaters (Fan type)

cookers and old fridges...

Why would these appliances have earth leakage under normal operation?

If they leaked 3 mA each you'd be in trouble with an RCD -

I don't understand how they are leaking current to earth - whether they are inductive or not, that's nothing to do with the cpc.

 

[sparkytim]

That's about the only thing in this thread that is making sense to meLine and Neutral could be being cut at slightly different times (might only be milliseconds apart) and the RCD is sensing the imbalance.

headbang Ha Ha, Scrap That!! I've just realised what I said. Once line or neutral are cut there won't be any current flow to be 'imbalanced' (if thats a word) headbang

.

.

Why would these appliances have earth leakage under normal operation?

If they leaked 3 mA each you'd be in trouble with an RCD -

I don't understand how they are leaking current to earth - whether they are inductive or not, that's nothing to do with the cpc.

All heating elements are leaky and often its only when several are all in circuit at the same time you get a total leakage thats exceeds the 24 m A or so threshold for 30 m A RCDs ( as shown by ramp test)

 

[ianmacd]

I don't understand the double pole switching thing that just does not make sense to me.

+1

 

[revjames]

(as shown by ramp test)

essential for any installations in a garage...... :coat

 

[springcrocus]

There is an interesting article HERE that tries to explain the "why" of nuisance tripping.

 

[ADS]

All heating elements are leaky and often its only when several are all in circuit at the same time you get a total leakage thats exceeds the 24 m A or so threshold for 30 m A RCDs ( as shown by ramp test)

If someone wants to explain to me how my kettle is leaking current to earth, I'm all ears

 

[revjames]

If someone wants to explain to me how my kettle is leaking current to earth, I'm all ears

simple. current takes the normal path through the heating element. some current manages to sneak past the insulation and flows back through the metal covering of the element back to earth.

 

[sparkytim]

I concur with above

 

[fletchflash]

another one is surge protection leads for rcd tripping

 

[ADS]

simple. current takes the normal path through the heating element. some current manages to sneak past the insulation and flows back through the metal covering of the element back to earth.

So you're telling me if I do an insulation resistance test - line & neutral connected together to earth - on my kettle, I'll get a reading of about 115 K ohms (which would give 2 mA leakage).

I'm not having it - I'll be doing the test tomorrow

 

[sparkytim]

depends how old is the kettle?

try it when cold then when hot

Have you got a leakage meter?

i.e. low current reading (m Amps) clamp meter

clamp round meter tails L& N enclosed by clamp but Not the earth and see what it reads with kettle of then on.

This is a good way to track down Rcd tripping situations as recommended by Megger

 

[revjames]

So you're telling me if I do an insulation resistance test - line & neutral connected together to earth - on my kettle, I'll get a reading of about 115 K ohms (which would give 2 mA leakage).I'm not having it - I'll be doing the test tomorrow

no I'm not saying your kettle is doing that. The post was about which items in particular are most likely to be prone to leakage currents. Any type of heating element, particularly those found in cookers, kettles storage heaters are the most likely culprits.

 

[batty]

I have a customer with old storage heater were I did cu change. Put it on Rcbo to comply with regs have had to go back countless times to reset trip now when cold element is fine but when heating up insulation breaks down and trips out so at present time its on Mcb when weather gets better I will go back and change element. Now if it wasn't for Rcbo I would not have to do this. 17th edition has a lot to answer to I think. I don't understand what ADS is saying here.

 

[ADS]

no I'm not saying your kettle is doing that. The post was about which items in particular are most likely to be prone to leakage currents. Any type of heating element, particularly those found in cookers, kettles storage heaters are the most likely culprits.

No, the question was:

Hi,What appliances in domestic houses are most likely to have earth leakage causing an RCD to trip?

Apart from Washing Machine, Tumble, Dishwasher, Fridge Freezer, Microwave

Thanks

And I'm not having it that all the items, listed on this thread, leak current to earth - I think this is another myth

I'll give you the computer and some other electronic devices - but not the rest.

If all the items listed leaked between 1 mA and 2 mA in normal operation then you would have to comply with 543.7.1.3 in pretty much every installation you did.

543.7.1.3 The wiring of every final circuit and distribution circuit intended to supply one or more items of equipment, such that the total protective conductor current is likely to exceed 10 mA, shall have a high integrity protective connection complying with one or more of the following:

It then goes on to list 5 requirements - Pg 133 BRB

So, there is no way that those items are going to leak enough current to trip an RCD unless they were actually faulty.

depends how old is the kettle?try it when cold then when hot

Have you got a leakage meter?

i.e. low current reading (m Amps) clamp meter

clamp round meter tails L& N enclosed by clamp but Not the earth and see what it reads with kettle of then on.

This is a good way to track down Rcd tripping situations as recommended by Megger

I have an IR tester - thats good enough

Tested my kettle this morning - hot and cold - 500v L & N connected together tested to earth - >299 Mohm

Not a chance of leaking to earth