30mA RCD'S and cooker circuits

[batty]

Evening all

With the introduction of the 17th edition of the wiring regs and having to comply ie cables in walls. Cooker circuits needing to be put through 30mA RCD.

I was always told not to put Cooker and Immersion circuits through Rcd's and if neccassary they should be put through a 100mA TD Rcd. I was called out tonight to a customer. She has had some building work done and the builders electrician has fitted a 17th edition board with two RCD'S so Oven is on one of these RCD'S but it is occasionally tripping RCD out. She was told by electrician that fitted board that the element needs changing. I tried oven this evening and it got up to temp without tripping RCD. All i could say was that if i had fitted board i would have fitted RCBO rather than RCD. I could replace element but this would not guarantte RCD would not trip out. Oven is 6 years old. I do not no what the answer is. When i do new installations and rewires i shall be putting cooker circuits through metal conduit.

Batty

 

[davetheglitz]

Personally I haven't come across this tripping - but 30mA means there must be a breakdown of insulation somewhere. Insulation resistance must be around 8k ohms - very low!!!!

I've heard as a rumour that elements can need heat to drive out moisture - so if a trip was to occur it would be at the beginning of the heat up cycle. Not sure I believe this for the sealed elements that you get nowadays.

Have you done any insulation tests on the oven or the system?

 

[batty]

Hello Dave,

No i didn't do any testing as it was mainly to look for oven serial number as she had said element had gone wrong. She is going away so will not be using oven until she gets back. So will have a look then.

Batty

 

[The Godfather]

Evening guys, can I add, my boys have never seen this cooker tripping situation, as for the Immersion, well I could possibly understand that going leaky before finally breaking down.

Don

 

[ElectekAir]

I know this post is late. With cooker elements on RCD, if the cooker is not used for a while or at least all the elements fat, oil and moisture will get into the unused elements.

If you remove the cooker cct from rcd and put all the elements on high it will drive out the moisture and burn off the oil or fat, then simply put it back on to RCD and you wont need to change the elements.

Tell the homeowner to ensure that they turn on all the elements at least once a week.

Problem solved

 

[a1]

Tell the homeowner to ensure that they turn on all the elements at least once a week.

As if they'd listen. You ask people to push a "Test Button" once quarterly on their RCD / RCBO, and that isn't done.

 

[steptoe]

big favourite call out on XMAS day this one!

I remember going once to this job (60miles away, heavy snowfall in the sticks, took me about 2hours) at about 11am one xmas day, cooker not working.

was a youngish lad, about 19, was cooking xmas dinner for his girlfriend, cooker not working.

checked the main fuse,(1361), OK, 100mA rcd still on,(TT).

right go and see if neon lights up,

flicked the switch, 2gang vertical with big red switch,

and the bloke says,

WHATS THAT BIG RED SWITCH FOR..????

FFS, he hadnt even turned it on!!!!!!

some f**king idiots in this world......

 

[a1]

:^O

An oven is for life - not just Christmas. :^O

 

[Theorysparky]

phone call this week

shower not working ,,no red light water cold

pull the bit of string that hangs down and try again,,,,,muppets

 

[a1]

:^O :^O:^O

 

[SPECIAL LOCATION]

pull the bit of string that hangs down and try again,,,,,muppets

Nah... Pull in the bit of string is PUPPETS...

like in Thunderbirds, Stringray, Captain Scarlet... The Woodentops oh thats a bit old... :_|

MUPPETS..

is stickin yer arm up their ar5e!!! ; \ ]

NO strings!!! :^O :^O:^O

 

[Evans Electric]

Interesting comment from ElectekAir about drying out elements, thanks for sharing that. I found that the old sit-up-and- beg cookers (still get them in flats and older properties) would always trip RCDs , hence the fashion for using split load consumers. As regards immersion heaters, I always put them through an RCD for safety. Over the years I have removed old heaters to find them either split open or even just two prods left in the water but resistance is too high to blow fuse or trip.

I think the answer under the 17th is to fit all RCBOs ( Bl***y expensive though )

Deke

 

[binky]

Once had my own oven tripping RCD - turned out to be grill element breaking down. Replaced element, and problem disappeared. Think I might by some PAT testing gear, as this sort of thing is quite common

 

[kme]

WHY????

Your insulation tester`ll pick this up. Why get ANOTHER expensive bit of kit, so it can duplicate a fuction you already have??????

 

[Apache]

Because gadgets are fun?

 

[kme]

Because gadgets are fun?

Good answer. My wife disagrees though. She says gadgets are, erm...... expensive :_| .

BUT SHE`S N O T THE ONE THAT GETS TO PLAY WITH `EM.

So she wouldn`t know their TRUE value. ]

 

[SPECIAL LOCATION]

Because gadgets are fun?

but Girls are more fun! ] ]BlushingBlushing

 

[SPECIAL LOCATION]

but Girls are more fun! ] ]BlushingBlushing

oops SORRY! :|BlushingPray

 

[kme]

pmsl @ SL

 

[a1]

Well - they do say in the song that they just wanna have fun.