Powder coat oven keeps tripping mains rcd all off a sudden?

[adamfromayr]

Hi

Okay my powder coat oven i built was fine until today!

I had it working kept on for more than an hour etc

Pretty pleased with it all

2 x 2000w elements fitted and then wired into a 32a blue socket to the 42a isolator switch

But today its started tripping i looked insid emy control panel and all looks good and heating elements heat up maybe for 2 mins, then trips my mains rcd

I was guessing damp weather? condensation or something? as was working okay and for no reason today starts tripping all off a sudden? any idea guys?

 

[adamfromayr]

hows it a fire waiting to happen? Its all HIGH TEMP cabling and high temp crimps etc etc and now running it through armoured conduit up to the new elements

Just a wee note too all: I Tetsed the AMP On the element cables and its running 18amps for bothe elements!

Test the new elements hopefully Friday

 

[westward10]

Those spade connectors on the element don't appear to have fared well with the heat the insulation is all but burnt off.

 

[MFS Electrical]

Disagree dude, As only when the oven is switch on it trips!

Take on board what these lads are telling you, the oven may be on that RCD but there are multiple other things on the RCD as well. The RCD trips at 0.03Amps (in reality it’s lower) it could well be cumulative leakage from the multiple circuits that this RCD feeds and the possible leakage from the oven is just enough to meet the trip threshold. Of course It could also be the oven itself and only the oven causing the problem.
Check your Elements for any signs of expansion or burn marks and check where those wires pass through the enclosure as they could have been rubbing and chafed through. Otherwise it would be time to get a spark in.

 

[westward10]

Time to get a skip in.

 

[MFS Electrical]

Still waiting on new elements guys, o did the prep work today and look at this: CONDENSATION? Shocking as in an oven but in a cold Garage?

So is the Condensation causing the RCD To trip? The heating the element mixed with the almost wet surface, Least im owning up here guys see piccie!

Im going too add The New Covered Cable and also make a small access port, this time doing it 100% and adding Silica Jel sachets inside the base! to prevent the nasty condomsensation as seen in my piccie!

View attachment 46254

It seems as though the wire that connects to the left side of that element may be touching the earthed braid or the enclosure at the slot

 

[MFS Electrical]

I know i asked for help but i think its doesnt have to be covered as im using special oven high temp cable and crimps, all the photos on google on inside ovens dont have anything covering the crimps and oven cable they are always left bare, so im not covering the ends in anything! the cable i will cover in high temp cable outer sheath from high temp cable ive got, i think if i make sure the new armoured conduit going into the base of my oven and up to the first element is 100% dry free and i cover the elements in a steel grill im going to be okay! Will also use silca gel pouches in the steel box section where the cables run

Hopefully that will be that

The box section will be holding far more heat than in the back of an oven the temp in that box section will continue to heat up and exceed the rating of the cable you probably need vents and perhaps a fan for that box section to keep the temp down

 

[pirate]

Folks call me pedantic...
post #41
CONDENSATION later becomes condomsensation...
the former occurs when, say, a hot steamy air mass hits a cold surface...
the latter? I couldn't possibly comment...

 

[murpad]

Think you definitely need to check element connections, JB connections, also what size is flex as it looks like it's feeding both elements

 

[a-z electrics]

When you say you've "checked the cables" have you done an insulation resistance test to earth? Or have I missed something..

 

[adamfromayr]

Hey You Guys!!!!!!

Okay as promised im Back no i didnt fry myself lol

Okay you guys, went and did it much better, My big mistake is bringing in the feed in from the side and down a narrow box section, NO NO NO i tell you!

Simply not good enough Adam is it!

So after scratching my greying hair! i cam up that for sure these elements "need more space! narturally i wanted all my oven space for cooking things! sadly i had to give up some of the much needed space to allow the elements plenty of breathing space, space where its no where near any other metals!

So i decided to make a new Base! and ineserted the elements in the middle if the sheet metal¬

I then raised the sheet metal of the orginal oven base using 2 x box sections and wired into a metal clad housing and fed it from a new hole in the back!

So far its working 100% guys

If anyone else ever does this keep in mind that you will need a good bit of depth for the elements! Looking at around 10-15cm! at least

Anyway guys thanks for all you taking the time to help me out!

and took all your comments on board!

Will i make a bigger oven? yes i sure will you guys, i sure will!

Until then this old Locker will keep em buring

Till we speak again

Adios my Amigos!