Immersion

Bruthal

dupeters wrote: »

Maybe bruthal,
but what if it the element has a fault of 28mA? And it was causing the rcd to trip? along with say 3mA of cumulative?
Adding it to its own rcbo would be ok for now.

I really don't get your line of thinking. To change an element that is not tripping an rcbo simply because it might in the future is pointless.

i think for safety sake (and because it is a cheap purchase/remidy) that changing the whole immersion coil would be the right way to continue.
I know if it was my house with my kids using hot water every day i couldn't sleep knowing my immersion had a fault which i had not repaired but transferred to another device?

If it is not tripping an rcbo, and is earthed properly, it is fine. There is no danger. If that concerns you that badly, you should avoid using all electrical devices.

Something leaking 30ma has a leakage impedance of 7666 ohms. Too high to be of much danger.

Helpmefarm

Try isolating one element at a time both live and netural needs to be disconnected and find which element has the fault and use the good one to keep you going! New immersions not expensive as cheap as a seperate rcbo and ya wont need an expensive electrican like me!

Bruthal

Helpmefarm wrote: »

Try isolating one element at a time both live and netural needs to be disconnected and find which element has the fault and use the good one to keep you going! New immersions not expensive as cheap as a seperate rcbo and ya wont need an expensive electrican like me!

He might need an expensive plumber though.

Gr1f

Hi guys, any idea where i can get an Immersion Element for decent price in Dublin/Bray? Mine's gone.

LooksLikeRain

Eurosales in sandyford usually have them in stock

2011

Gr1f wrote: »

Hi guys, any idea where i can get an Immersion Element for decent price in Dublin/Bray? Mine's gone.

Chadwicks and Heat Merchants in Bray.

Cerco

You could also try the wholesalers facing Chadwickes on Boghall Rd. - used to T.R. Reilly I think.

Gr1f

Gr1f wrote: »

Hi guys, any idea where i can get an Immersion Element for decent price in Dublin/Bray? Mine's gone.

Got one and all fixed after much swearing and gnashing of teeth.

kingden2006

if you know which circuit it is just bell the cable out using your multimeter from your fuse board to your immersion,that will tell you wether or not there is a break in the cable or not,but you are much better of using an insulation resistance meter/megger,because sometimes if the cable is broke using a multimeter you"ll still get continuity because it"s not completely broken,thats why you should use a megger.
also if you already have an mcb you only need and rcd not an rcbo.

Bruthal

kingden2006 wrote: »

if you know which circuit it is just bell the cable out using your multimeter from your fuse board to your immersion,that will tell you wether or not there is a break in the cable or not,but you are much better of using an insulation resistance meter/megger,because sometimes if the cable is broke using a multimeter you"ll still get continuity because it"s not completely broken,thats why you should use a megger.
also if you already have an mcb you only need and rcd not an rcbo.

A multimeter would show up open circuits better than the higher voltage meggar, particularly where the open circuit gap is microscopic.

jca

I'd say its leaking to earth when under mains voltage. I wouldn't take any chances with an Immersion.

Bruthal

jca wrote: »

I'd say its leaking to earth when under mains voltage. I wouldn't take any chances with an Immersion.

What chances are being taken? If its an earth fault, RCD trips. Even in the days before RCDs I often seen elements which had split, so the actual element conductor was into the water. Still no serious danger despite the automatic assumptions of water and electricity = doom.

kingden2006

yes your right there bruthal

jca

Bruthal wrote: »

What chances are being taken? If its an earth fault, RCD trips. Even in the days before RCDs I often seen elements which had split, so the actual element conductor was into the water. Still no serious danger despite the automatic assumptions of water and electricity = doom.

Its tripping the RCD. Replace it, End of.
Elements exposed to the water:eek: What did you do?? Put a tuppence piece in place of the ceramic fuse.... A tidy merchant...

Bruthal

jca wrote: »

Its tripping the RCD. Replace it, End of.

I always have to laugh at that "end of" phrase, as if it means infallibility on the users part. Would you replace an immersion that is tripping an RCD if it was a neutral touching an earth in the switch for example? Or under the immersion cover itself? No simple tests, just replace?

More often than not, they do need replacing, but I like to test and confirm, rather than just replace without question.

Elements exposed to the water:eek: What did you do?? Put a tuppence piece in place of the ceramic fuse.... A tidy merchant...

And what do you do when a fuse blows, replace the immersion?

jca

Bruthal wrote: »

I always have to laugh at that "end of" phrase, as if it means infallibility on the users part. Would you replace an immersion that is tripping an RCD if it was a neutral touching an earth in the switch for example? Or under the immersion cover itself? No simple tests, just replace?

More often than not, they do need replacing, but I like to test and confirm, rather than just replace without question.



And what do you do when a fuse blows, replace the immersion?

Obviously after doing wiring checks and the wiring is perfect, the RCD keeps tripping/the fuse keep blowing when re-connected to the immersion, yep, replace the immersion...end of.

Bruthal

jca wrote: »

Obviously after doing wiring checks and the wiring is perfect, the RCD keeps tripping/the fuse keep blowing when re-connected to the immersion, yep, replace the immersion...end of.

A right, thats a different "end of" than...

Its tripping the RCD. Replace it, End of.

Obviously, from the sound of it, you have not experienced split immersion failures. They were common enough in failures before RCDs were used on immersions. Immersion element open circuits inside casing, and arcs across the tiny opening, burning the mineral insulation, eventually splitting the copper jacket.

With no RCD to trip from earth fault, they continued working with the owner oblivious except that the water heated slower, if at all, with some current flowing into the water and onto the element casing. It could clearly be heard, as instead of a clean buzzing sound, (2 different tones for bath and sink if you put ear to cylinder when its on), it would make a distinctive sizzling sound, as the element conductor was exposed to the water.

And fuses didnt really blow with the above, as it was usually far enough from the live end of the element that the element conductor resistance was high enough to not blow fuses. The resistance of the bath element is about 18 ohms, so if the failure was half way along or more toward the neutral end, that would be 9 ohms, not enough to blow a 20 amp fuse, especially when the element conductor probably didnt contact the copper jacket, or if it did, it was not good contact, it often just ended up exposed to the water.

jca

Bruthal wrote: »

A right, thats a different "end of" than...

Obviously, from the sound of it, you have not experienced split immersion failures. They were common enough in failures before RCDs were used on immersions. Immersion element open circuits inside casing, and arcs across the tiny opening, burning the mineral insulation, eventually splitting the copper jacket.

With no RCD to trip from earth fault, they continued working with the owner oblivious except that the water heated slower, if at all, with some current flowing into the water and onto the element casing. It could clearly be heard, as instead of a clean buzzing sound, (2 different tones for bath and sink if you put ear to cylinder when its on), it would make a distinctive sizzling sound, as the element conductor was exposed to the water.

And fuses didnt really blow with the above, as it was usually far enough from the live end of the element that the element conductor resistance was high enough to not blow fuses. The resistance of the bath element is about 18 ohms, so if the failure was half way along or more toward the neutral end, that would be 9 ohms, not enough to blow a 20 amp fuse, especially when the element conductor probably didnt contact the copper jacket, or if it did, it was not good contact, it often just ended up exposed to the water.

One of the reasons not to ignore RCD/ELCB trips especially regarding the Immersion. It happened in the Fathers place back in the 70's on the bath element. The whole cylinder was delivering mild shocks to myself and the brother much to our amusement. The aul lad wasn't so impressed and he fixed it in typical miserly 70's style. Yep you've guessed it....He disconnected the bath element and it was sink only:pac::pac: For the next 20 years:D Oh yea a grand sparing man...

DieselPowered

mikehammer67 wrote: »

you need a megger

Which megger is needed for this type of troubleshooting?

jca

DieselPowered wrote: »

Which megger is needed for this type of troubleshooting?

I think you need to replace it;);)

DieselPowered

jca wrote: »

I think you need to replace it;);)

Thats not the question

jca

DieselPowered wrote: »

Thats not the question

Is that you Da?

DieselPowered

jca wrote: »

Is that you Da?

I'll hold out for someone that knows what they are talking about.

adrian92

Suggest remove the immersion circuit from the RCD ciruit. The normal leakage may be tripping all. Re wire to a non-RCD circuit or re-wire it with its own RCD.

kingden2006

an insulation resistance meter or megger as they are more commonly known as on building sites,they are used for measuring the resistance of insulation by sending a higher voltage down the cable normally 500 volts or 1000volts,you test between live and neutral,live and earth and neutral and earth the reading should be in the megaohms...this test only insure"s that there is no damage to the cable/insulation or leakage,whichever you like to call it.
i think the elcb is done away with now,as far as i know,but i could be wrong.

2011

adrian92 wrote: »

Re wire to a non-RCD circuit

No, that is not permitted.

2011

kingden2006 wrote: »

i think the elcb is done away with now,as far as i know,but i could be wrong.

It has not been done away with, just a name change. It is now referred to as an "RCD"

jca

DieselPowered wrote: »

I'll hold out for someone that knows what they are talking about.

I think the posters here and the immersion itself are telling you to replace the immersion. You've checked the wiring and it's ok? You've checked the switch and its ok? You may bite the bullet and replace the elements. A horrible job.

2011

I would think that everything has been covered thoroughly now.