During the winter we tend to only use Caravan Club sites. Every time I use my Erberspacher on the mains it trips the site box I am connected to. Sometimes immediately and as we have noted having been on for some hours and during the middle of the night when we wake up cold. What I find strange is the trip at the site box and not on the Van. Also if i connect the system at home on mains it tripped once but no more. Apart from any suggestions for the fault like a a possible faulty Earth does anybody also know how many amps a C.C. site box takes before it trips. We have tried it with everything else turned off and still it tripped on site. I took it to a Erberspacher Agent who tried first of all to tell me there was nothing wrong with it but when he used a Caravan Cable it tripped but then he tried another Cable and it tripped again,just baffled that it does not trip at the Van or on house mains.:Sad:?