Help please!

[Prince1983]

Hi All,

I hope you guys are well and have had a good day!

its actually my first time on here and I was wondering if you could give me some advice please.

i wired up an oven with a cooker switch and then cooker outlet plate. Did the continuity test and insulation resistance test and everything was ok with results. I then switched the mcb on and everything was fine. I then switched on the cooker switch and the oven went bang!!! The RCD tripped but the MCB did not so looking for an earth fault. Then I disconnected everything. I did an insulation resistance test from the CU to the cooker switch and the readings were greater than 999M ohms. i then did an IR test from cooker switch to the outlet plate. everything was then also ok. i then did an IR test on the cooker lead and the earth to line reading was 0.26M ohms suowing an earth fault. I then connected from the Consumer Unit to the cooker switch and outlet plate without the cooker connected and everything was fine no trips. Could you please help me in deciphering this problem, thank you.

 

[Darkwood]

PS dont meggar with the hob/cooker connected you may damage it also the low M-ohms maybe the electronics etc in the hob/cooker like timer boards or displays ...hopefully you haven't damaged it with 500v ...another schoolboy error lets hope luck is on yourside.

This is really basic stuff i take it as you state Officer? as occupation you have no hands on experience .... you really could do with gaining some valuable experience under a well weathered competent sparks for a yr or 2 or you'll end up making some costly mistakes.

Dare i ask what kind of course you have done to get qualified and how long it lasted?

 

[Prince1983]

Thanks guys for your help. If I'm honest the large junction box type screws threw me, thus not expecting any markings and nor a link to the metal back. When I've normally connected a cooker it's to the cooker switch direct. Well I shall hope that Lady Luck is on my side and I shall update you tomorrow regarding the cooker. Thank you again for your help.

 

[Prince1983]

The course that I have done is the 2365 c&g which lasted one year intensive Monday to Friday 9-4 level 2 and 3.

 

[Darkwood]

Im not the biggest fan of intensive learning its attractive because its fast but is flawed as you get no onsite real world experience which is a must IMHO to give your theory some real reference...

I would recommend you get an experienced wing man who can guide you for a few years before jumping in he deep end feet first.

You can be taught how to swim through theory in the classroom but the reality could see you struggle if not drown as soon as you take to water.

I hope you take it as constructive advice as the basic mistakes here are worrying even if a moment of stupidity you followed it by Insulation testing with the appliances still connected which is all in your college notes yet you haven't applied it when on site.

 

[GLENNSPARK]

Thank you. I understand that was not the best thing to do but I immediately just took it as a connection box. I have now rectified that problem. But with the cooker flex into the the hob connection unit now reading at 0.26M ohms, is it safe to assume that the flex will need replacing and the rest of the hob will be ok or is it a case of having to buy a new hob? Your help is greatly appreciated and I still don't know why I did that, it was rather silly of me making that mistake.

leave leccy alone will you...

 

[ChrisElectrical88]

Scary stuff. How much did you charge for connecting this new cooker?

 

[Prince1983]

I didn't its my own

 

[GLENNSPARK]

Im not the biggest fan of intensive learning its attractive because its fast but is flawed as you get no onsite real world experience which is a must IMHO to give your theory some real reference...

I would recommend you get an experienced wing man who can guide you for a few years before jumping in he deep end feet first.

You can be taught how to swim through theory in the classroom but the reality could see you struggle if not drown as soon as you take to water.

I hope you take it as constructive advice as the basic mistakes here are worrying even if a moment of stupidity you followed it by Insulation testing with the appliances still connected which is all in your college notes yet you haven't applied it when on site.

i would have thought this young un would have been the wing man Dark...