Hi, Can anyone shed any light on what is happening here. 9kw single phase oven in commercial premises. Intermittent fault when opening the 45a D.P switch for the oven this trips the rcd. This is a split rcd board, the rcd side contains 3 rings & the oven unprotected side contains 3 lighting circuits & a free standing electric cooker. Rcd test o.k. Ir test are all above 4 Mohms. ramp test 27ma.
Cheers
Cheers