We have a newly installed RCD that trips in a very puzzling way. Let me
explain.

We have two separate consumer units. One has a split load RCD and supplies
the back of the house - it has never tripped. The other is an older "fuse
wire" consumer unit with 16 circuits supplying the front of the house. It is
protected by an RCD on its incoming feed and it is this RCD that trips
several times per day.

There is no single cause that trips it - sometimes it is a light, sometimes
the computer, etc. What is really puzzling is that the TV can trip it. The
TV is in the back of the house fed from the other consumer unit and
therefore is not even supplied through the troublesome RCD.

The RCD has been checked with an RCD tester and it passed OK.

Any ideas? Our electricians are baffled.

Thanks