Induction hob tripping 30mA rcd

[Npt88]

Morning all.
I'm in search of ideas.
Been installing an induction hob on a 6mm radial backed up by a 32a mcb. Came to power up yesterday and with all hobs on its throwing out the 30mA main switch rcd. (It's a TT system). Iv tested all my cables and there all clear so it's taking it out on earth leakage. I'm thinking there may be a few other items in the house with leakage and this is just taking it over the threshold. I have done a ramp test etc on the rcd and its fine.
The way I see it I can either put everything on rcbos and pop a main switch in or 100mA time delayed. Or split load DB with 2 30mA rcds and separate the circuits. But they are both expensive options. Any ideas guys??
Or I suppose leave the earth disconnected JOKE!!

 

[monkeyelectric]

Does it trip straight away? Have you tried switching everything off at the board and leaving hob on to see if its leakage or do you have a leakage meter?

 

[Npt88]

No it's not tripping straight away. Only when I have 2+ hobs on. Nah only got a standard clamp meter and don't do mA. I'm off back in a bit because they've had the hob exchanged as they thought it was faulty so il try just leaving it on. If it is leakage that's not due to a fault how can I get round it without sounding like I just want more money and doing the options I said above.
Thanks

 

[monkeyelectric]

Split the tails and put a seperate rcd in for the hob, should'nt cost much, better confirm it is leakage first though, what was the main rcd tripping at?

 

[Npt88]

Agrhhhh that's a good idea It was tripping at 21mA
Thanks

 

[monkeyelectric]

No probs, 21mA is a bit low, i've never ever had an rcd trip at 30mA, we're being had! They're always 27 or below

 

[Npt88]

Yeh there always under like. But I don't fancy changing the rcd for one that could possibly be tripping at 27 for the extra 6mA and encounter the same problem. Il go back try this new hob. Try it on its own. If needs be pop in an rcd in an enclosure as you said

 

[DieselShunter]

Have you considered the radical approach of ringing or emailing the tech support department of the appliance manufacturer and asking them whether this is normal, and if so what they recommend as a solution?

Their response my provide useful ammunition for you explaining to the client why you're charging them for installation of a new 11kV sub-station.

 

[Npt88]

Yeah contacted ikea where it was purchased and its made by another firm and there not open during the weekends and I'm working away the next two weeks.